Astronomical Calendar - A.D. 2021

Dominical Letter: "C" - Used in a Perpetual Calendar. For Non-Leap Year of 2021.


Authored By Glenn A. Walsh *** Sponsored By Friends of the Zeiss
Electronic Mail: < astrocalendar@planetarium.cc > *** Internet Web Cover Page: < http://www.planetarium.cc >
This Internet Web Page: < https://buhlplanetarium4.tripod.com/astrocalendar/2021.html >
SpaceWatchtower Blog
2021 January

Internet Web Site Master Index for the History of
The Buhl Planetarium and Institute of Popular Science, Pittsburgh

SpaceWatchtower Blog


ASTRONOMICAL / CALENDAR EVENTS --

A.D. 2021

January ** February ** March

April ** May ** June

July ** August ** September

October ** November ** December


2021

Equinoxes (EQX), Solstices (SOLC), and Cross-Quarter (XQ) Days

Chronological Cycles and Eras

Astro Calendar
Current Month

Astro Calendar
Archives


Constellations
For Year

Star Charts
For Year

Moon Phases:
2021 * Today
Archive

Planets, Stars, Sky Events:
Today *** This Week

Solar System *** Archive

Occultations:

Moon / Bright Stars
Moon / Bright Planet & Asteroid
Moon / Planets & Bright Stars
Major Planets & Moons
Archive

10,000-Year
Calendar

Astronomy Links

Science Links

Astronomical Glossary
Click here for links to the Moon, planets, star clusters, stars, and other astronomical terms referred to in this Astronomical Calendar.

2021 Equinoxes (EQX), Solstices (SOLC), and Cross-Quarter (XQ) Days - Archive

* Tue., Feb. 2 - Traditional Astronomical Cross-Quarter Day Imbolc, and also Candlemas, better known as Groundhog Day. (First traditional Astronomical Cross-Quarter Day of year; approximate mid-way point in Winter season: Feb. 1 Eve - Feb. 2).
(Groundhog Day at Gobler's Knob, Punxsutawney PA 15767, home of Punxsutawney Phil: - Sunrise: 7:26 a.m. EST / 12:26 UTC) .

* Wed., Feb. 3, 9:40 a.m. EST / 14:40 UTC - Actual Astronomical Cross-Quarter Day (First actual Astronomical Cross-Quarter Day of year; mid-way point in Winter season: ~Feb. 4).
Traditional Cross-Quarter Day.

* Sat., March 20, 5:37 a.m. EDT / 9:37 UTC - Vernal Equinox - Season of Spring begins in Earth's Northern Hemisphere: beginning of New Year (solar calendar) in Afghanistan and Iran. (~March 20)

* Sat., May 1 - Traditional Astronomical Cross-Quarter Day Beltaine, better known as May Day - Second traditional Astronomical Cross-Quarter Day of year; approximate mid-way point in Spring season (May 1).

* Wed., May 5, 2:36 p.m. EDT / 6:36 UTC - Actual Astronomical Cross-Quarter Day Beltaine, better known as May Day - Second traditional Astronomical Cross-Quarter Day of year; mid-way point in Spring season (~May 5-6).
Traditional Cross-Quarter Day.

* Sun., June 20, 11:32 p.m. EDT / June 21, 3:32 UTC - Summer Solstice - Season of Summer begins in Earth's Northern Hemisphere (~June 21).
Also see 1985-1991: Summer "Solstice Day," Annual Free Day at Buhl Planetarium.

* Sun., Aug. 1 - Astronomical Mid-Point of Summer - Traditional Astronomical Cross-Quarter Day, also known as “Lammas” (in the United Kingdom) and “Lughnassad” (in Ireland). Considered approximate date of First Harvest (third traditional cross-quarter day of the year), approximately between the Midsummer Solstice and the Autumnal Equinox (July 31 Eve - Aug. 1).

* Sat., Aug. 7, 2:53 a.m. EDT / 6:53 UTC - Astronomical Mid-Point of Summer - Actual Astronomical Cross-Quarter Day (halfway between the June Solstice and September Equinox: ~Aug. 6 to 7).
Traditional Cross-Quarter Day.

* Wed., Sept. 22 - Falls Prevention Awareness Day (First day of Fall: ~Sept. 22-23).

* Wed., Sept. 22, 3:21 p.m. EDT / 19:21 UTC - Autumnal Equinox - Season of Autumn begins in Earth's Northern Hemisphere. (~Sept. 22)
Also see: Harvest Moon.

* Oct. 31 / Nov. 1 / Nov. 2 - Traditional Astronomical Cross-Quarter Day Samhain or "All-Hallowsmas", better known as Halloween (Oct. 31 - "All Hallows Eve"), All-Saints Day (Nov. 1), All-Souls Day (Nov. 2) (fourth and last traditional cross-quarter day of year).

What is a "Cross-Quarter Day" ?
What is the Astronomical significance of
Halloween, All-Saints Day, and All-Souls Day?
Link 1 *** Link 2 *** Link 3 *** Link 4

* Sat., Nov. 6, 11:50 p.m. EST / Nov. 7, 3:50 UTC - Actual Astronomical Cross-Quarter Day (fourth and last actual cross-quarter day of the year: ~Nov. 6-7).
Traditional Cross-Quarter Day.

* Tue., Dec. 21 - Homeless Persons' Memorial Day. (First day of Winter; longest night of the year: ~Dec. 21)

* Tue., Dec. 21, 10:59 a.m. EST / 15:59 UTC - Winter Solstice - Season of Winter begins in Earth's Northern Hemisphere. (~Dec. 21-22)
Also see: "The Stars of Winter" and "The Star of Bethlehem" Planetarium Sky Dramas (web sites include entire planetarium show scripts), performed each Winter in the Theater of the Stars of Pittsburgh's original Buhl Planetarium and Institute of Popular Science.

Chronological Cycles and Eras Corresponding to Anno Domini (A.D.) 2021 or 2021 Common Era (C.E.) - Archive

Unless otherwise indicated, all dates are given in terms of the Gregorian Calendar.
For recent years, January 14 of the Gregorian Calendar corresponds to January 1 of the Julian Calendar.

Dominical Letter: "C" - Used in a Perpetual Calendar. For Non-Leap Year of 2021.
Epact: 16.
Golden Number (Lunar Cycle): VIII.
Roman Indiction: 14.
Solar Cycle (28-year cycle of the Julian calendar): 14.
Julian Period (Year of): 6734.

Byzantine Year 7530 Begins Sept. 14.
Jewish Year (A.M.) 5782 Begins at local Sunset, Sept. 7.
Chinese / Asian Lunar New Year (Lunar Calendar) - Year of the Ox 4719 Begins Feb. 12.
Roman A.U.C. (Dates from the founding of the City of Rome) Year 2774 Begins Jan. 14.
Nabonassar Year 2770 Begins April 23.
Japanese (Reiwa) Year 3 - Begins May 1.
Grecian Year (Selucidae) 2333 Begins Sept. 14 (or Oct. 14).
Indian Year (Saka) 1943 Begins March 22.
Diocletian Era (Era of the Martyrs) Year 1738 Begins Sept. 11.
Islamic (Hegira) (FCNA date) Year 1443 Begins at first viewing of lunar crescent (New Moon) on evening (after local Sunset) of Aug. 9.
Baha'i Year 177 Begins at local Sunset on March 18.

NEWS: Astronomy, Space, Science

History of Buhl Planetarium and Institute of Popular Science, Pittsburgh


A.D. 2021

Astronomical Calendar: 2021 January
Monthly Observances This Month

Quadrantid Meteor Shower: Jan. 3 to 4

Moon Phases:
2021 * Today

Planets, Stars, Sky Events:
Today *** This Week
Solar System
Constellations *** Star Chart

Occultations:
Moon / Bright Stars
Moon / Bright Planet & Asteroid
Moon / Planets & Bright Stars
Major Planets & Moons

View International Space Station (ISS)
Rocket Launches This Month: Link 1 *** Link 2 *** Link 3 *** Link 4

Equinoxes (EQX), Solstices (SOLC), and Cross-Quarter (XQ) Days For This Year.
Chronological Cycles and Eras For This Year.
Dominical Letter: "C" - Used in a Perpetual Calendar. For Non-Leap Year of 2021.

Astronomical Glossary
of Terms Used

Astronomical Calendar
Archives

Other
Astronomical Calendars: Link 1 * Link 2

10,000-Year Calendar

Rise & Set Times

Current Sky Events & Astro Phenomena

News: Astronomy, Space, Science --

Weekly: SpaceWatchtower Blog

Daily: SpaceWatchtower Twitter Feed

History of Pittsburgh's Original
Buhl Planetarium and Institute of Popular Science

Astronomy Links

Science Links


a.m. = Ante-Meridiem (Morning: Midnight to a moment before Noon)

p.m. = Post-Meridiem (Afternoon & Evening: a moment after Noon to a moment before Midnight of the next day)

EST = Eastern Standard Time *** EDT = Eastern Daylight Saving Time *** UTC = Coordinated Universal Time

SPECIAL NOTES:
(1) All astronomical or sky observations are always weather-permitting.
(2) For calendar entries which describe a relationship between two or more celestial objects, unless otherwise noted all relationships between celestial objects are visual relationships as seen from Earth only.


* Nov. 1 to April 30 - Use of life jackets by every person on a small boat (less than 16 feet in length), during cold-weather months, is mandatory. (Nov. 1 to April 30)

* Thur., 2020 Dec. 31 - Make Up Your Mind Day. (Dec. 31)

* Thur., 2020 Dec. 31 - Eve of New Year's Day (Traditional). (Dec. 31)

* Thur., Dec. 31 (2017), 11:59:59 p.m. EST / 2018 Jan. 1, 4:59:59 UTC - Anniversary: Suspension of broadcasting, and conclusion of all-news radio programming after 42 years (having started all-news programming on 1975 Oct. 15), by KQV-AM 1410, Pittsburgh (one of the nation's oldest radio stations, having started on 1919 November 19): Link 1 *** Link 2 (Dec. 31)

* Thur., 2020 Dec. 31, 7:00:00 p.m. EST / 2021 Jan. 1, 0:00:00 UTC - Marks the beginning of the New Year by the Coordinated Universal Time scale, the time scale used by many scientists. (Dec. 31)

* Fri., Jan. 1 - Feast of the Circumcision of Christ - Eighth day of the 12 days of Christmas: Dec. 25 to Jan. 5. During the Gregorian Calendar reform, Pope Gregory XIII, chose the Feast of the Circumcision of Christ as the beginning of the New Year in the Roman Catholic Church's Liturgical Year; previously, the Feast of the Annunciation on March 25 (also the Vernal Equinox in the "original" Julian Calendar adopted by the second King of Rome, Numa Pompilius, in the 7th century B.C.) had been considered the beginning of the New Year. (Jan. 1)

* Fri., Jan. 1 - Last day of Kwanzaa - Week-long holiday observance honoring African-American heritage. (Dec. 26 to Jan. 1)

* Fri., Jan. 1 (1863) - Anniversary: Emancipation Proclamation issued by U.S. President Abraham Lincoln during the American Civil War, which decreed that slaves in the rebellious states are free forever. (Jan. 1)

* Fri., Jan. 1 - First Day Hikes in America’s State Parks. (Jan. 1)

* Fri., Jan. 1 - Public Domain Day (Annual) - Copyrighted works from 95 years ago are now copyright-free.
Also see: NPR News Story. (Jan. 1)

* Fri., Jan. 1 (1927) - Anniversary: Establishment of the nation's second radio network, the NBC Blue Network, which focused on news and public affairs programming. Due to a Federal Communications Commission (FCC) rule-making in 1942, NBC was forced to divest the NBC Blue Network, which became the ABC Radio Network. ABC Radio continued the news emphasis; ABC Radio was the first network to report the shooting of U.S. President John F. Kennedy on 1963 November 22 (6 minutes and 50 seconds after the shooting). (Jan. 1)

* Fri., Jan. 1, 12:00:00 Midnight (0:00:00) Prevailing Local Time - For Eastern Standard Time (EST) Zone in North America: 12:00:00 Midnight EST / 5:00:00 Coordinated Universal Time (UTC) which correlates with 12:00:00 Midnight EST - New Year's Day: New Calendar Year begins. (Jan. 1)

* Sat., Jan. 2, 9:00 a.m. EST / 14:00 UTC - Earth at perihelion (closest Earth approach to the Sun in New Year): 91,399,453 statute miles / 147,093,162 kilometers. (Jan. 2 to 5)

* Jan. 3 Evening to Jan. 4 Morning - Sun., Jan. 3, 10:00 a.m. EST / 15:00 UTC - (Best viewing: Midnight to Dawn) - Peak of Quadrantid Meteor Shower. (Jan. 3 to 4)

* Jan. 4 to 13, 8:00 to 10:00 p.m. Prevailing Local Time - CITIZEN SCIENCE: Monthly Globe at Night campaign, to raise public awareness of the impact of light pollution by encouraging everyone everywhere to measure local levels of night sky brightness and contribute observations on-line to a world map.

* Mon., Jan. 4 - Latest time of sunrise, for the year, for locales (such as Pittsburgh) at or near +40 North Latitude. (Jan. 4)

* Tue., Jan. 5 - National Bird Day. (Jan. 5)

* Tue., Jan. 5, Evening - "12th Night" of Christmas; end of the 12 days of Christmas, which began on Christmas Day. (Jan. 5)

* Wed., Jan. 6 - Feast of the Epiphany; the day after the "12th Night" of Christmas. Tradition celebrates Epiphany as day the Magi arrived in Bethlehem to present gifts to the Christ child. (Jan. 6)

* Wed., Jan. 6 - Orthodox Christmas Eve - As determined by Julian Calendar. (Jan. 6)

* Wed., Jan. 6 - National Returns Day - When the most UPS returns packages are sent back to retailers. (Jan. 5 to 6)

* Wed., Jan. 6, 4:37 a.m. EST / 9:37 UTC - Primary Moon Phase: Last Quarter.

* Thur., Jan. 7 - Orthodox Christmas - As determined by Julian Calendar. (Jan. 7)

* Fri., Jan. 8 (1918) - Mount Wilson Observatory Astronomer Harlow Shapley discovered true magnitude of Milky Way Galaxy and true location of Earth and our Solar System in the Milky Way Galaxy.
On 1941 November 19, Harvard College Observatory Director Harlow Shapley delivered the keynote address at the dedication for a rather unique 10-inch Siderostat-Type Refractor Telescope at Pittsburgh's original Buhl Planetarium and Institute of Popular Science. (Jan. 8)

* Fri., Jan. 8 (1851), 2:00 a.m. Paris Time - Earth's Rotation Day - Anniversary: French physicist Jean Leon Foucault develops a simple device to finally demonstrate and prove that the Earth rotates on its axis: Foucault Pendulum. He demonstrated the Foucault Pendulum, before scientists at the Paris Observatory, on 1851 February 3.
Near the end of his life, Jean Leon Foucault also developed the Siderostat-type Refractor Telescope. (Jan. 8)

* Sat., Jan. 9 - Library Card Registration Day. (2nd Saturday in January)

* Sat., Jan. 9 (1793) - First balloon flight in America. (Jan. 9)

* Sat., Jan. 9, 11:00 a.m. EST / 16:00 UTC - Moon at perigee: 228,283.7 statute miles / 367,387 kilometers.

* Sat., Jan. 9, 4:00 p.m. EST / 21:00 UTC - Mercury 1.7 degrees south of Saturn.

* Sun., Jan. 10 (1920) - Founding of the League of Nations. (Jan. 10)

* Sun., Jan. 10, 7:00 a.m. EST / 12:00 UTC - 2.3-DEGREE CIRCLE OF PLANETS LOW IN WESTERN SKY SHORTLY AFTER SUNSET: JUPITER, SATURN, MERCURY.

* Mon., Jan. 11 - Learn Your Name in Morse Code Day. (Jan. 11)

* Mon., Jan. 11 - National Milk Day. (Jan. 11)

* Mon., Jan. 11 - National Human Trafficking Awareness Day. (Jan. 11)

* Mon., Jan. 11 - National Clean Off Your Desk Day. (2nd Monday of January)

* Mon., Jan. 11, 6:00 a.m. EST / 11:00 UTC - Mercury 1.5 degrees south of Jupiter.

* Mon., Jan. 11, 3:00 p.m. EST / 20:00 UTC - Venus 1.5 degrees north of the Moon.

* Tue.,Jan. 12 (1958) - Establishment of the Special Committee on Space Technology of the National Advisory Committee for Aeronautics (NACA: established 1915 March 3), the predecessor of the National Aeronautics and Space Administration (NASA). (Jan. 12)

* Wed., Jan. 13 - New Year's Eve, according to the Julian Calendar. (Jan. 13)

* Wed., Jan. 13, 12:00 Midnight EST / 5:00 UTC - Primary Moon Phase: New Moon - Lunation #1213

* Wed., Jan. 13, 8:00 p.m. EST / Jan. 14, 1:00 UTC - Jupiter 3 degrees north of the Moon.

* Thur., Jan. 14 - Beginning of the New Year, according to the Julian Calendar. (Jan. 14)

* Thur., Jan. 14, 3:00 a.m. EST / 8:00 UTC - Mercury 2 degrees north of the Moon.

* Fri., Jan. 15 (1929) - Anniversary: Birthday of Martin Luther King, Jr. (Observed - USA: Third Monday in January): Birth of Rev. Dr. Martin Luther King, Jr.. (Jan. 15)

* Fri., Jan. 15 (2001) - Anniversary: Launch of Wikipedia, free-of-charge, on-line encyclopedia. (Jan. 15)

Sat., Jan. 16 (1786) - National Religious Freedom Day - Commemorates Virginia General Assembly's adoption of Thomas Jefferson's landmark Virginia Statute for Religious Freedom. (Jan. 16)

* Sun., Jan. 17 - Kid Inventors’ Day (K.I.D.), on January 17 in honor of the birth of famous inventor Benjamin Franklin, who invented the first swim flippers at the age of 12. (Jan. 17)

* Mon., Jan. 18 - Martin Luther King, Jr. Day (Observed - USA: Third Monday in January): Birth of Rev. Dr. Martin Luther King, Jr.: 1929 Jan. 15. (Third Monday in January)

* Wed., Jan. 20 (1937 to present, on years divisible by four) - U.S. Presidential Inauguration Day. (Jan. 20, on years divisible by four)

* Wed., Jan. 20, 4:01 p.m. EST / 21:01 UTC - Primary Moon Phase: First Quarter.

* Thur., Jan. 21 - Squirrel Appreciation Day. (Jan. 21)

* Thur., Jan. 21, 1:00 a.m. EST / 6:00 UTC - Mars 5 degrees north of the Moon.

* Thur., Jan. 21, 1:00 a.m. EST / 6:00 UTC - Uranus 3 degrees north of the Moon.

* Thur., Jan. 21, 8:00 a.m. EST / 13:00 UTC - Moon at apogee: 251,257.7 statute miles / 404,360 kilometers.

* Thur., Jan. 21, 7:00 p.m. EST / Jan. 22, 0:00 UTC - Mars 1.7 degrees north of Uranus.
ALSO: Mars, Uranus, and the Waxing Gibbous Moon congregate together, in the southwestern sky shortly after local sunset (Uranus will be very dim; binoculars or telescope may be necessary.)

* Sat., Jan. 23 - Sun rises for first time in year (after Sun setting for last time of previous year on November 18: total of 67 days of darkness) in the northern-most town in United States of America: Barrow, Alaska (330 miles north of the Arctic Circle). (Jan. 23)

* Sat., Jan. 23, 10:00 p.m. EST / Jan. 24, 3:00 UTC - Saturn in conjunction with the Sun (Saturn not visible, even with a telescope).

* Jan. 24 to 30 - Celebrate Catholic Schools Week. (End of January / Beginning of February)

* Jan. 24 to 30 - Tax Identity Theft Awareness Week. (Last business week of January / first business week of February).

* Sun., Jan. 24 - National Compliment Day. (Jan. 24)

* Mon., Jan. 25 (1915) - First transcontinental telephone call. (Jan. 25)

* Mon., Jan. 25, 6:00 p.m. EST / 23:00 UTC - Moon 0.3 degree north of Open Star Cluster M35

* Tue., Jan. 26 - Australia Day, commemorating the first landing in Australia by Captain Arthur Phillip. (Jan. 26)

* Wed., Jan. 27 (1967) - Anniversary: Apollo 1 Fire - Three astronauts perished in flash-fire during pre-launch test: Gus Grissom, Ed White, Roger Chaffee. (Jan. 27)

* Wed., Jan. 27 (1926) - First public demonstration, in London, of a black-and-white, mechanical television system. (Jan. 27)

* Wed., Jan. 27 - Holocaust Remembrance Day (UN). (Jan. 27)

* Wed., Jan. 27 - National Bubble-Wrap Appreciation Day, first used by IBM to safely ship computers in 1961. (Last Monday of January)

* Thur., Jan. 28 (1986) - Anniversary: STS Space Shuttle Challenger (Teacher-in-Space Mission) explosion shortly after launch; seven astronauts perished: Francis Scobee, Michael Smith, Elison Onizuka, Judith Resnik, Ronald McNair, Gregory Jarvis, Christa McAuliffe (Teacher-in-Space). (Jan. 28)
Viewed at Pittsburgh's original Buhl Planetarium and Institute of Popular Science (a.k.a. Buhl Science Center).

* Thur., Jan. 28 - Data Privacy Day. (Jan. 28)

* Thur., Jan. 28, 2:16 p.m. EST / 19:16 UTC - Primary Moon Phase: Full Moon - Wolf Moon.

* Thur., Jan. 28, 9:00 p.m. EST / Jan. 29, 2:00 UTC - Jupiter in conjunction with the Sun (Jupiter not visible, even with a telescope).

* Fri., Jan. 29 - Earned Income Tax Credit (EITC) Awareness Day. (Last Friday in January)

* Fri., Jan. 29 - Puzzle Day. (Jan. 29)

* Fri., Jan. 29 - Mercury at perihelion.

* Sun., Jan. 31 (1958) - Anniversary: First successful launch, by the USA, of an artificial satellite: Explorer 1. (Jan. 31)

Astronomical Calendar: 2021 February
Monthly Observances This Month

3 Space Probes Reach Mars in February:
Feb. 9: United Arab Emirates' Hope Orbiter
Feb. 10: China's Tianwen-1 Orbiter & Lander
Feb. 18: NASA's Perseverance Rover

Moon Phases:
2021 * Today

Planets, Stars, Sky Events:
Today *** This Week
Solar System
Constellations *** Star Chart

Occultations:
Moon / Bright Stars
Moon / Bright Planet & Asteroid
Moon / Planets & Bright Stars
Major Planets & Moons

View International Space Station (ISS)
Rocket Launches This Month: Link 1 *** Link 2 *** Link 3 *** Link 4

Equinoxes (EQX), Solstices (SOLC), and Cross-Quarter (XQ) Days For This Year.
Chronological Cycles and Eras For This Year.
Dominical Letter: "C" - Used in a Perpetual Calendar. For Non-Leap Year of 2021.

Astronomical Glossary
of Terms Used

Astronomical Calendar
Archives

Other
Astronomical Calendars: Link 1 * Link 2

10,000-Year Calendar

Rise & Set Times

Current Sky Events & Astro Phenomena

News: Astronomy, Space, Science --

Weekly: SpaceWatchtower Blog

Daily: SpaceWatchtower Twitter Feed

History of Pittsburgh's Original
Buhl Planetarium and Institute of Popular Science

Astronomy Links

Science Links


a.m. = Ante-Meridiem (Morning: Midnight to a moment before Noon)

p.m. = Post-Meridiem (Afternoon & Evening: a moment after Noon to a moment before Midnight of the next day)

EST = Eastern Standard Time *** EDT = Eastern Daylight Saving Time *** UTC = Coordinated Universal Time

SPECIAL NOTES:
(1) All astronomical or sky observations are always weather-permitting.
(2) For calendar entries which describe a relationship between two or more celestial objects, unless otherwise noted all relationships between celestial objects are visual relationships as seen from Earth only.


* Nov. 1 to April 30 - Use of life jackets by every person on a small boat (less than 16 feet in length), during cold-weather months, is mandatory. (Nov. 1 to April 30)

* Jan. 31 to February 6 - Celebrate Catholic Schools Week. (End of January / Beginning of February)

* Feb. 1 to 5 - Tax Identity Theft Awareness Week. (Last business week of January / first business week of February).

* Mon., Feb. 1 (2003) - Anniversary of STS Space Shuttle Columbia disintegration during re-entry; seven astronauts perished: Rick Husband, William McCool, David Brown, Kalpana Chawla, Michael Anderson, Laurel Clark, Ilan Ramon. (Feb. 1)

* Mon., Feb. 1 (1865) - National Freedom Day -Date in 1865 when U.S. President Abraham Lincoln signed a resolution proposing the Thirteenth Amendment to the United States Constitution prohibiting slavery. (Feb. 1)

* Mon., Feb. 1 - National Change Your Password Day!. (Feb. 1)

* Tue., Feb. 2 - African American Coaches Day about the benefits of working with a personal or business coach. (First Tuesday in February)

* Tue., Feb. 2 - Traditional Astronomical Cross-Quarter Day Imbolc, and also Candlemas, better known as Groundhog Day. (First traditional Astronomical Cross-Quarter Day of year; approximate mid-way point in Winter season: Feb. 1 Eve - Feb. 2).
(Groundhog Day at Gobler's Knob, Punxsutawney PA 15767, home of Punxsutawney Phil: - Sunrise: 7:26 a.m. EST / 12:26 UTC) .
Actual Cross-Quarter Day.

* Feb. 3 to 12, 8:00 to 10:00 p.m. Prevailing Local Time - CITIZEN SCIENCE: Monthly Globe at Night campaign, to raise public awareness of the impact of light pollution by encouraging everyone everywhere to measure local levels of night sky brightness and contribute observations on-line to a world map.

* Wed., Feb. 3 (1851) - Anniversary: Jean Leon Foucault first demonstrates, before scientists in the Meridian Room of the Paris Observatory, the Foucault Pendulum, which is a proof that the Earth rotates on its axis. He had invented the device on 1851 January 8.
Near the end of his life, Jean Leon Foucault also developed the Siderostat-type Refractor Telescope. (Feb. 3)

* Wed., Feb. 3 - National Girls and Women in Sports Day. (Feb. 3)

* Wed., Feb. 3, 9:40 a.m. EST / 14:40 UTC - Actual Astronomical Cross-Quarter Day (First actual Astronomical Cross-Quarter Day of year; mid-way point in Winter season: ~Feb. 3, 4).
Traditional Cross-Quarter Day.

* Wed., Feb. 3, 2:00 p.m. EST / 19:00 UTC - Moon at perigee: 229,979.4 statute miles / 370,116 kilometers.

* Thur., Feb. 4 - Transit Equity Day to honor Rosa Parks on her birthday, for her act of resistance by refusing to give up her seat on the bus in Montgomery, Alabama in 1955, which was a catalyst for the civil rights movement. (Feb. 4 - birthday of Rosa Parks)

* Thur., Feb. 4 - World Cancer Day (WCD). (Feb. 4)

* Thur., Feb. 4 - Thank A Mailman Day. (Feb. 4)

* Thur., Feb. 4 - Lichun - Beginning of first Solar term (of 24 Solar terms in one year) of traditional East Asia calendars (begins when the Sun reaches the celestial longitude of 315° and ends when it reaches the longitude of 330°); also known as the start of Spring (Occurs each year around Feb. 4)

* Thur., Feb. 4, 12:37 p.m. EST / 17:37 UTC - Primary Moon Phase: Last Quarter.

* Fri., Feb. 5 - National Weatherperson's Day - Birth of one of America's first weather observers, John Jeffries (picture): 1744 February 5. (Feb. 5)

* Fri., Feb. 5 - National Wear Red Day - Go Red for Women movement to heart disease in women (American Heart Association). (First Friday in Feb.)

* Sat., Feb. 6, 12:00 Midnight EST / 5:00 UTC - Venus 0.4 degree south of Saturn.

* Feb. 7 to 13 - World Orphan Week. (1st full week of February)

* Sun., Feb. 7 (1863) - Periodic Table (of Chemical Elements) Day. (Feb. 7)

* Mon., Feb. 8 (1910) - Anniversary: Founding of the Boy Scouts of America. (Feb. 8)

* Mon., Feb. 8 - National Clean Out Your Computer Day. (Second Monday in February)

* Mon., Feb. 8, 9:00 a.m. EST / 14:00 UTC - Mercury in inferi.or conjunction with the Sun (Mercury not visible, even with a telescope).

* Tue., Feb. 9 - The United Arab Emirates' first interplanetary space mission, the Hope Orbiter, arrives at Mars.

* Tue., Feb. 9 - Safer Internet Day. [Second day (Tuesday) of the second (business) week of February]

* Tue., Feb. 9, 3:00 p.m. EST / 20:00 UTC - Asteroid 2 Pallas in conjunction with the Sun (Pallas not visible, even with a telescope).

* Wed., Feb. 10 - China's Tianwen-1 orbiter and lander space probes arrive at Mars; lander scheduled to touch-down on the planet in May.

* Wed., Feb. 10, 6:00 a.m. EST / 11:00 UTC - Saturn 3 degrees north of the Moon.

* Wed., Feb. 10, 3:00 p.m. EST / 20:00 UTC - Venus 3 degrees north of the Moon.

* Thur., Feb. 11 (1732) - Anniversary of birth of first American President, George Washington, according to Julian Calendar (also known as "Old Style Calendar"), at use at that time; according to Gregorian Calendar, which we use today, George Washington's birthday occurred on Feb. 22. (Feb. 11)
Science & U.S. Presidents
See also: Washington's Birthday Observed / Presidents' Day * Washington's Birthday Actual (Julian Calendar) * Washington's Birthday Actual (Gregorian Calendar) * Lincoln's Birthday.

* Thur., Feb. 11 - International Day for Women and Girls in Science. (Feb. 11)

* Thur., Feb. 11 - National Inventors' Day, anniversary of the birth of the inventor Thomas Alva Edison. (Feb. 11)

* Thur., Feb. 11, 7:00 a.m. EST / 12:00 UTC - Venus 0.4 degree south of Jupiter.

* Thur., Feb. 11, 2:05 p.m. EST / 19:05 UTC - Primary Moon Phase: New Moon - Lunation #1214.

* Fri. through Mon., Feb. 12 to 15 - CITIZEN SCIENCE: The Great Backyard Bird Count. (Presidents' Day holiday weekend, starting on Friday)

* Fri., Feb. 12 - Chinese / Asian Lunar New Year, based on a lunisolar calendar of which dates indicate both the moon phase and the time of the solar year. This day is the first day of the Primary Moon Phase of New Moon (as determined from the China time zone), of the first Chinese lunar month in the Chinese Lunar Calendar system.This marks the beginning of the Chinese / Asian Lunar New Year Year of the Ox.

* Fri., Feb. 12 (1809) - Anniversary: Birth of 16th American President, Abraham Lincoln. (Feb. 12)
Science & U.S. Presidents
See also: Washington's Birthday Observed / Presidents' Day * Sa Washington's Birthday Actual (Julian Calendar) * Washington's Birthday Actual (Gregorian Calendar) * Lincoln's Birthday.

* Fri., Feb. 12 (1809) - Anniversary: Birth of English naturalist, Charles Darwin; Darwin Day. (Feb. 12)

* Sat., Feb. 13 - World Radio Day (WRD). (Feb. 13)

* Sat., Feb. 13 - Galentine’s Day - Fun holiday for women, created in 2010 by the NBC-TV program, Parks and Recreation. (Feb. 13 - always day before St. Valentine's Day)

* Sun., Feb. 14 - St. Valentine's Day. (Feb. 14)

* Sun., Feb. 14 - Library Lovers Day. (Feb. 14)

* Sun., Feb. 14 - International Book Giving Day. (Feb. 14)

* Sun., Feb. 14 - National Have a Heart Day to promote awareness of our food choices so as to get or maintain a healthy heart. (Feb. 14)

* Sun., Feb. 14 - National Organ Donor Day. (Feb. 14)
Also see: Story of the youngest heart-lungs transplant recipient, who received her first transplant operation shortly after visiting Pittsburgh's Buhl Planetarium in November of 1985.

* Sun., Feb. 14 - Autism Sunday / International Day of Prayer for Autism and Asperger Syndrome. (Second Sunday of February)

* Mon., Feb. 15 - Presidents' Day / Washington's Birthday Observed. (USA Federal Holiday: Third Monday in Feb.)
Science & U.S. Presidents
See also: Washington's Birthday Observed / Presidents' Day * Washington's Birthday Actual (Julian Calendar) * Washington's Birthday Actual (Gregorian Calendar) * Lincoln's Birthday.
Also see: The Astronomy President.

* Mon., Feb. 15 (1564) - Anniversary: Birth of Italian Astronomer Galileo Galilei. (Feb. 15)

* Mon., Feb. 15 (2013) - Chelyabinsk, Russia Meteor, a super-bolide caused by an approximately 20 m (66 ft) near-Earth asteroid, which caused wide-spread damage in Chelyabinsk, Russia. (Feb. 15)

* Mon., Feb. 15 (1820) - Susan B. Anthony Day - Anniversary of the birth of Susan B. Anthony and commemoration of women's suffrage in the United States. (Feb. 15)

* Mon., Feb. 15 - Singles Awareness Day. (Feb. 15)

* Tue., Feb. 16 - Mardi Gras / Fat Tuesday / Carnival Tuesday / Shrove Tuesday / Pancake Tuesday / Pancake Day. (Day before Ash Wednesday)

* Wed., Feb. 17 (1869) - Anniversary: Periodic Table of Chemical Elements. (Feb. 17)

* Wed., Feb. 17 (2015) - Fireball over Pittsburgh seen in several states. (Feb. 17)

* Wed., Feb. 17 -
** Ash Wednesday
** Beginning of Lent. (First Wednesday in Lent, 46 days before Easter Sunday)
Will Christians Agree to Fix the Date of Easter?

* Wed., Feb. 17 - Random Acts Of Kindness Day. (Feb. 17)

* Wed., Feb. 17, 11:00 a.m. EST / 16:00 UTC - Uranus 3 degrees north of the Moon.

* Thur., Feb. 18, 3:00 p.m. EST / 20:00 UTC - NASA's Perseverance Rover scheduled to land inside the Jezero Crater (width of 28 statute miles / 45 kilometers) on Mars.
Click Here for live coverage of landing event.

* Thur., Feb. 18 (1930) - Anniversary: Date of discovery of Planet Pluto (now designated Dwarf Planet 134340 Pluto) discovered by Clyde Tombaugh working at Lowell Observatory in Flagstaff, Arizona. (Feb. 18)

* Thur., Feb. 18 - Introduce a Girl to Engineering Day. (Thursday of National Engineering Week)

* Thur., Feb. 18, 5:00 a.m. EST / 10:00 UTC - Moon at apogee: 251,324.1 statute miles / 404,467 kilometers.

* Thur., Feb. 18, 6:00 p.m. EST / 23:00 UTC - Mars 4 degrees north of the Moon.

* Fri., Feb. 19 (1473) - Anniversary: Birth of famous Polish astronomer Nicolaus Copernicus. (Feb. 19)
A portrait of Nicolaus Copernicus, donated to Pittsburgh's original Buhl Planetarium and Institute of Popular Science by the Polish Arts League of Pittsburgh, hung on the Mezzanine of Buhl Planetarium.
Also see photograph of the inscription of the name "Copernicus," just under the outer planetarium dome of Pittsburgh's original Buhl Planetarium and Institute of Popular Science.

* Fri., Feb. 19 (1968) - Anniversary: National premiere on National Educational Television (NET - predecessor of PBS, the Public Broadcasting Service) of landmark children's television program, Mister Rogers' Neighborhood, which included puppet character King Friday the 13th (originated at WQED-TV channel 13 in Pittsburgh). (Feb. 19)

* Fri., Feb. 19, 1:47 p.m. EST / 18:47 UTC - Primary Moon Phase: First Quarter.

* Sat., Feb. 20 (1491) - Anniversary: "Comet of 1491" which, until 2002, was considered the closest comet to ever approach the Earth. Today, this comet is not considered the closest comet to ever approach the Earth, due to the unreliability of data. (Feb. 20)
More information.

* Sat., Feb. 20 - World Pangolin Day. (Feb. 20)

* Sat., Feb. 20 - Venus at aphelion.

* Feb. 21 to 27 - National Engineers Week. [Third or fourth week in February (Sunday through Saturday), which includes George Washington's actual birthday of February 22]

* Feb. 21 to 27 - Montessori Education Week. (Last week of February / first week of March)

* Feb. 21 to 27 - National Brotherhood / Sisterhood Week. (Week which includes Feb. 22, which coincides with George Washington's birthday)

* Sun., Feb. 21 - International Mother Language Day. (Feb. 21)

* Feb. 22 to 26 - Fair Use / Fair Dealing Week, commissioned by the Association of Research Libraries. (Last full business week of February)

* Feb. 22 to 26 - America Saves Week. (Last week of Feb. - Same week as Military Saves Week)

* Feb. 22 to 26 - Military Saves Week. (Last week of Feb. - Same week as America Saves Week)

* Mon., Feb. 22 (1732) - Anniversary: Birth of first American President, George Washington, according to Gregorian Calendar, which we use today; according to Julian Calendar (also known as "Old Style Calendar") at use at that time, George Washington's birthday occurred on Feb. 11. (Feb. 22)
Science & U.S. Presidents
See also: Washington's Birthday Observed / Presidents' Day * Washington's Birthday Actual (Julian Calendar) * Washington's Birthday Actual (Gregorian Calendar) * Lincoln's Birthday.

* Mon., Feb. 22 - National Brotherhood Day. (Feb. 22 - coincides with George Washington's birthday)

* Mon., Feb. 22, 3:00 a.m. EST / 8:00 UTC - Moon 0.4 degree north of M35 Open Star Cluster.

* Tue., Feb. 23 - World Spay Day. (Last Tuesday of every February)

* Wed., Feb. 24 (1914) - Anniversary: Concept of the Projection Planetarium. (Feb. 24)

* Thur., Feb. 25 - Equilux when considering Civil Twilight (Dawn before sunrise and Dusk after sunset) - When considering Civil Twilight, the day when daylight and darkness, both, have the same length of hours and minutes. Occurs twice each year, approximately 23 days before the Vernal Equinox and 23 days after the Autumnal Equinox. (Feb. 25-26, Oct. 15)

* Thur., Feb. 25 - Digital Learning Day. (4th Thursday in February)

* Feb. 26, 27, 28 - National Girl Scout Cookie Weekend. (Last weekend of February / first weekend of March)

* Sat., Feb. 27 - International Polar Bear Day. (Feb. 27)

* Sat., Feb. 27, 3:17 a.m. EST / 8:17 UTC - Primary Moon Phase: Full Moon - Snow Moon.

* Sun., Feb. 28 - Mercury reaches highest point in morning sky, with an apparent visual magnitude of 0.1. Mercury visible above eastern horizon shortly before local sunrise.

* Sun., Feb. 28 - Rare Disease Day. (Last day of February: Feb. 28 or 29)

* Sun., Feb. 28, ~4:55 a.m. Prevailing Local Time - Andromeda Galaxy (M31) rises in the northeastern sky.

* Feb. 29 to March 1 (1504 Feb. 29 to March 1) - Anniversary: Total Lunar Eclipse used by Christopher Columbus, to scare the natives of Jamaica into providing food and other provisions for his sailors. (Feb. 29 to March 1)
Also see first recorded lunar eclipse in continental North America.

Astronomical Calendar: 2021 March
Monthly Observances This Month

"March roars in like a lion and goes out like a lamb."
(Origin: Constellations Leo the Lion & Aries the Ram)

Standard Time Ends / Daylight Saving Time Resumes
Second Sunday in March at 2:00 a.m. Prevailing Local Time

Spring Begins: ~ March 19, 20, 21

Moon Phases:
2021 * Today

Planets, Stars, Sky Events:
Today *** This Week
Solar System
Constellations *** Star Chart

Occultations:
Moon / Bright Stars
Moon / Bright Planet & Asteroid
Moon / Planets & Bright Stars
Major Planets & Moons

View International Space Station (ISS)
Rocket Launches This Month: Link 1 *** Link 2 *** Link 3 *** Link 4

Equinoxes (EQX), Solstices (SOLC), and Cross-Quarter (XQ) Days For This Year.
Chronological Cycles and Eras For This Year.
Dominical Letter: "C" - Used in a Perpetual Calendar. For Non-Leap Year of 2021.

Astronomical Glossary
of Terms Used

Astronomical Calendar
Archives

Other
Astronomical Calendars: Link 1 * Link 2

10,000-Year Calendar

Rise & Set Times

Current Sky Events & Astro Phenomena

News: Astronomy, Space, Science --

Weekly: SpaceWatchtower Blog

Daily: SpaceWatchtower Twitter Feed

History of Pittsburgh's Original
Buhl Planetarium and Institute of Popular Science

Astronomy Links

Science Links


a.m. = Ante-Meridiem (Morning: Midnight to a moment before Noon)

p.m. = Post-Meridiem (Afternoon & Evening: a moment after Noon to a moment before Midnight of the next day)

EST = Eastern Standard Time *** EDT = Eastern Daylight Saving Time *** UTC = Coordinated Universal Time

SPECIAL NOTES:
(1) All astronomical or sky observations are always weather-permitting.
(2) For calendar entries which describe a relationship between two or more celestial objects, unless otherwise noted all relationships between celestial objects are visual relationships as seen from Earth only.


* Nov. 1 to April 30 - Use of life jackets by every person on a small boat (less than 16 feet in length), during cold-weather months, is mandatory. (Nov. 1 to April 30)

* Feb. 28 to March 6 - National Consumer Protection Week. (First full week of March)

* March 1 to 5 - Open Education Week. (First week of March)

* March 1 to 5 - National School Breakfast Week. (First school week of March)

* March 1 to 7 - World Orphan Week. (Feb. or March)

* Mon., March 1 (1504 Feb. 29 to March 1) - Anniversary of total lunar eclipse used by Christopher Columbus, to scare the natives of Jamaica into providing food and other provisions for his sailors. (Feb. 29 to March 1)
Also see Mo first recorded lunar eclipse in continental North America.

* Mon., March 1 - Beginning of Meteorological Spring Season in Northern Hemisphere. (March 1)

* Mon., March 1 - Beginning of Autumn Season in Australia. (March 1)

* Mon., March 1 - St. David's Day. (March 1)

* Mon., March 1 - World Compliment Day. (March 1)

* Mon., March 1 - Zodiacal Light visible, with difficulty, after evening twilight in the western sky of Earth's Northern Hemisphere, for the next two weeks. (February, March)

* Tue., March 2 - Read Across America sponsored by the National Education Association to motivate children to read, in addition to helping them master basic skills. (Annual--on or near March 2, birthday of Dr. Seuss)

* Tue., March 2, 12:00 Midnight EST / 5:00 UTC - Moon at perigee: 227,063.3 statute miles / 365,423 kilometers.

* Wed., March 3 - World Maths Day. (First Wednesday in March)

* Wed., March 3 (1915) - Establishment of the National Advisory Committee for Aeronautics (NACA), the predecessor of the National Aeronautics and Space Administration (NASA). (March 3)

* Wed, March 3 - World Wildlife Day. (March 3)

* Thur., March 4 - World Engineering Day. (March 4)

* Thur., March 4 (1681) - Pennsylvania Charter Day - William Penn received charter, for what became the Commonwealth of Pennsylvania, from Great Britain's King Charles II on 1681 March 4. (March 4)

* Thur., March 4 (1793 until 1933, on the year immediately following the year of a U.S. Presidential Election) - U.S. Presidential Inauguration Day. (March 4)

* Thur., March 4 - National Grammar Day. (March 4)

* Thur., March 4, 1:00 p.m. EST / 18:00 UTC - Asteroid 4 Vesta at opposition (Vesta visible, approx. local sunset to local sunrise, weather-permitting; binoculars or telescope necessary).

* March 5 to 14, 8:00 to 10:00 p.m. Prevailing Local Time - CITIZEN SCIENCE: Monthly Globe at Night campaign, to raise public awareness of the impact of light pollution by encouraging everyone everywhere to measure local levels of night sky brightness and contribute observations on-line to a world map.

* Fri., March 5 (1868) - Anniversary: Railway Air Brake patented by George Westinghouse in Pittsburgh. (March 5)

* Fri., March 5 - Employee Appreciation Day. (First Friday of March)

* Fri., March 5, 7:00 a.m. EST / 12:00 UTC - U.S. Space-walk #72 (ISS Expedition 64) outside of the International Space Station, lasting about 6:5 hours NASA Flight Engineer Kate Rubins and Japan Aerospace Exploration Agency (JAXA).
NASA-TV live coverage begins on March 5 at 5:30 a.m. EST / 10:30 UTC.

* Fri., March 5, 2:00 a.m. EST / 7:00 UTC - Mercury 0.3 degree north of Jupiter.

* Fri., March 5, 8:30 p.m. EST / March 6, 1:30 UTC - Primary Moon Phase: Last Quarter.

* Sat., March 6 - Open Data Day. (Feb. or March; 1st Sat. in March)

* Sat., March 6 (1869) - Professor Dimitri Ivanovich Mendeleev's first Periodic Table of the Elements was presented to, and published by, the Russian Chemical Society. (March 6)

* Sat., March 6, 6:00 a.m. EST / 11:00 UTC - Mercury - Greatest elongation (separation) west from the Sun (27 degrees); apparent visual magnitude: 0.0.
Good time to look for Mercury, just above the eastern horizon, shortly before local sunrise, weather-permitting; viewers should try to find a high vantage point, without visual obstructions from hills, trees, or buildings.

* March 7 to 13 - Sleep Awareness Week®. (Coincides, each year, with conversion to Daylight Saving Time; the calendar week before the time change)

* March 7 to 13 - Teen Tech Week. (March: Second Week)

* March 7 to 13 - Wildfire Prevention Week. [Pennsylvania: Spring (Second week of March), Autumn]

* Mon, March 8 - International Women's Day. (March 8)

* Tue., March 9, 6:30 p.m. EST / 23:00 UTC - Saturn 4 degrees north of the Moon.

* March 10 to April 12, September 24 through November 5 - Tsunami Preparedness Weeks. (mid-March through April, mid-September through early November)

* Wed., March 10 (1982) - 1982 date of first alignment of our Solar System's nine planets (including Pluto, which at that time was still considered a planet; Pluto is now designated a Dwarf Planet) since A.D. 1128. A 1974 book, The Jupiter Effect, had erroneously predicted several catastrophes to occur on this date in 1982, including a major earthquake on the San Andreas Fault in California. (March 10)

* Wed., March 10 (1876) - Anniversary: First successful telephone transmission of clear speech - when Alexander Graham Bell transmitted, "Mr. Watson, come here, I want to see you." Three days earlier, on March 7, Alexander Graham Bell received a U.S. patent for the telephone. (March 10)

* Wed., March 10, 11:00 a.m. EST / 16:00 UTC - Jupiter 4 degrees north of the Moon.

* Wed., March 10, 7:00 p.m. EST / March 11, 0:00 UTC - Neptune in conjunction with the Sun (Neptune not visible, even with a telescope).

* Wed., March 10, 8:00 p.m. EST / March 11, 1:00 UTC - Mercury 4 degrees north of the Moon.

Thur., March 11 - World Kidney Day. (March 11)

* Fri., March 12 - National Plant a Flower Day. (March 12)

* Fri., March 12 - World Day Against Cyber Censorship. (March 12)

* Fri., March 12 (1989) - Anniversary: Original proposal founding the World Wide Web on the Internet. (March 12).

* Fri., March 12 (1912) - Anniversary: Founding of the Girl Scouts of the United States of America. (March 12)

* Sat., March 13 (1781) - Anniversary: Planet Uranus discovery announced by Sir Frederick William Herschel. (March 13)

* Sat., March 13 (1938), 8:00 a.m. Prevailing Time - Anniversary: Beginning of the radio news program CBS World News Roundup, the longest-running, network news broadcast in America. (March 13)

* Sat., March 13, 5:21 a.m. EST / 10:21 UTC - Primary Moon Phase: New Moon - Lunation #1215.

* March 14 to 20 - Sunshine Week / Transparency Week. (2nd full week of March; includes Freedom of Information Day on March 16).

* Sun., March 14 - Pi Day, a holiday commemorating the mathematical constant π (pi). (March 14: 3.14)

* Sun., March 14 - Day of Planetaria. (2nd Sunday in March)

* Sun., March 14 - Mercury at aphelion.

* Sun., March 14, 2:00 a.m. Prevailing Local Time (Standard Time) - DAYLIGHT SAVING TIME BEGINS - Beginning in 2007, EARLY DUE TO NEW FEDERAL LAW. Civil Time changes from 2:00 a.m. Standard Time to 3:00 a.m. Daylight Saving Time (Second Sunday in March, 2:00 a.m. Prevailing Local Time).
Some States to Abandon Daylight Saving Time ?
Science of Daylight Saving Time.

* March 15 to 21 - Brain Awareness Week. (Second full week of March: Monday through Sunday)

* March 15 to 21 - Fix-a-Leak Week. (U.S. Environmental Protection Agency - third week of March: Monday through Sunday)

* Mon., March 15 - Napping Day. (Monday after the annual beginning of Daylight Saving Time)

* Mon., March 15 - Ides of March. (March 15)
Also see: Ides of March article on StarDate.org.

* Mon., March 15 - Buzzards return to Hinckley, Ohio (Cleveland suburb). (March 15)

* Mon., March 15 (1892) - First patent granted for the invention of the escalator, which resulted in production of the first escalator installed on the Old Iron Pier at Coney Island in New York City in 1896. (March 15)

* Tue., March 16 - Equilux - The actual day with equal hours and minutes of the Sun above the horizon, and equal hours and minutes of the Sun below the horizon. Occurs twice each year, approximately 3-to-4 days before the Vernal Equinox and 3-to-4 days after the Autumnal Equinox. (March 16, September 25)

* Tue., March 16 (1926) - Anniversary: American engineer, professor, physicist, and inventor Robert H. Goddard launched the first liquid-fueled (gasoline and liquid oxygen) rocket. (March 16)

* Tue., March 16 - Freedom of Information Day, the birthday of James Madison, who is widely regarded as the Father of the Constitution and as the foremost advocate for openness in government. (March 16)

* Tue., March 16, 10:00 p.m. EDT / March 17, 2:00 UTC - Uranus 3 degrees north of the Moon.

* Wed., March 17 - St. Patrick's Day. (March 17)

* Thur., March 18 - Transit Driver Appreciation Day. (March 18)

* Thur., March 18 - Awkward Moments Day. (March 18)

* Thur., March 18, 1:00 a.m. EDT / 5:00 UTC - Moon at apogee: 251,811.9 statute miles / 405,252 kilometers.

* Fri., March 19 (1918) - Anniversary: Standard Time Act authorized by the U.S. Congress, which legally established time zones in the United States. The law also established Daylight Saving Time (DST) to conserve energy during World War I, after being promoted by Pittsburgh business and civic leader Robert Garland. (March 19)
Previously, five North American time zones had been established by the American and Canadian railroads at precisely 12:00 Noon on 1883 November 18, upon a time signal sent over the telegraph from the Allegheny Observatory in Pittsburgh.

* Fri., March 19 - National Read To Me Day. (March 19)

* Fri., March 19 - St. Joseph's Day - Swallows return to Mission San Juan Capistrano, California. (March 19)

* Fri., March 19 - World Monopoly Day. (March 19)

* Fri., March 19, 2:00 p.m. EDT / 18:00 UTC - Mars 1.9 degrees north of the Moon.

* March 20 to 26 - Pennsylvania Medicine Cabinet Clean-up Week. (Week Beginning with the Vernal Equinox)

* March 20 to April 11 - Annual National Cherry Blossom Festival, Washington DC. (~ Vernal Equinox to mid-April)

* Sat., March 20 - Nowruz - Persian New Year Spring Festival, celebrated on the Vernal Equinox, particularly in Iran.

* Sat., March 20, 5:37 a.m. EDT / 9:37 UTC - Vernal Equinox - Spring Season begins in Northern Hemisphere of Earth. (~March 20)
Beginning of New Year (Solar Calendar) in Afghanistan and Iran / Persia (Nowruz), including being a holy day for the Zoroastrian Religion, and Bahá'í Naw-Rúz, one of nine holy days of the Bahá'í Faith. (~ March 19, 20, 21)

* Sat., March 20 - Sun - Earth Day. (NASA: Day of, or near, the Vernal Equinox, the first day of Spring)

* Sat., March 20 - Hypatia Day / Women in Science Day. (March 20)

* Sun., March 21 - Rosie The Riveter Day, commemorating the World War II poster, created by Pittsburgh's Westinghouse Electric Company, which promoted women doing their part in the war effort. (March 21)

* Sun., March 21 - World Poetry Day. (March 21)

* Sun., March 21 - Kick Butts Day to prevent youth use of tobacco products. (March 21).

* Sun., March 21 (1617) - Anniversary: Funeral of Native American Pocahontas (a.k.a. Rebecca Rolfe) at age ~ 21. (March 21)

* Sun., March 21, 10:40 a.m. EDT / 14:40 UTC - Primary Moon Phase: First Quarter.

* Sun., March 21, 1:00 p.m. EDT / 17:00 UTC - Moon 0.7 degree north of Open Star Cluster M35.

* March 22 to 26 - Solar Week. (Mid-to-Late March, Mid-to-Late October)

* March 22 to 26 - Flood Safety Awareness Week. (Pennsylvania: March).

* March 22 to 28 - National Drug & Alcohol Facts Week. (End of March / Beginning of April; Previously 4th week of January)

* Mon., March 22 - World Water Day. (March 22)

* Mon., March 22, 8:00 p.m. EDT / March 23, 0:00 UTC - Mars 7 degrees north of star Aldebaran.

* Tue., March 23 (1989) - National Near-Miss Day - Apollo Asteroid 1989FC, with a diameter of 300 meters, comes within 690,000 kilometers of the Earth in 1989. (March 23)

* Tue., March 23 - Diabetes Alert Day. (Fourth Tuesday of March)

* Wed., March 24 - Equal Pay Day - This date symbolizes how far into the year women must work to earn what men earned in the previous year. (Late March, Early to mid-April)

* Thur., March 25 - Feast of the Annunciation observed nine full months before Christmas Day. The Feast of the Annunciation on March 25 (also the Vernal Equinox in the "original" Julian Calendar adopted by the second King of Rome, Numa Pompilius, in the 7th century B.C.) had been considered the beginning of the New Year, until the Gregorian Calendar reform, when Pope Gregory XIII chose the Feast of the Circumcision of Christ (Jan. 1) as the beginning of the New Year in the Roman Catholic Church's Liturgical Year. (March 25)

* Thur., March 25 - Lady Day in England, the first of the four traditional English quarter days, was New Year's Day up to 1752 when, following the move from the Julian Calendar to the Gregorian Calendar, January 1 became the start of the year. Lady Day (for the Virgin Mary) is the traditional name of the Feast of the Annunciation of the Blessed Virgin (March 25) in some English-speaking countries. (March 25)

* Thur., March 25 - National Medal of Honor Day. (March 25)

* Fri., March 26 - Make Up Your Own Holiday Day. (March 26)

* Fri., March 26, 3:00 a.m. EDT / 7:00 UTC - Venus in superior conjunction (Venus not visible, even with a telescope).

* Sat., March 27, local sunset to April 4, local sunset - Jewish holiday of Passover.

* Sat., March 27, 8:30 to 9:30 p.m. Prevailing Local Time - Earth Hour annual environmental observance. (Saturday Late in March, 8:30 to 9:30 p.m. Prevailing Local Time)

* Sun., March 28, 2:48 p.m. EDT / 18:48 UTC - Primary Moon Phase: Full Moon - Worm Moon.

* Mon., March 29 (1848) - Anniversary: Ice jam stops flow of Niagara Falls for about 30 hours. (March 29)

* Tue., March 30 - Pennsylvania Female Veterans' Day. (March 30)

* Tue., March 30 - National Doctors' Day. (March 30)

* Tue., March 30 - World Bi-Polar Day, International Society for Bi-Polar Disorders, Pittsburgh. (March 30)

* Tue., March 30 - Zodiacal Light visible, with difficulty, after evening twilight in the western sky of Earth's Northern Hemisphere, for the next two weeks. (February, March)

* Tue., March 30, 2:00 a.m. EDT / 6:00 UTC - Moon at perigee: 223,885.6 statute miles / 360,309 kilometers.

* Wed., March 31 - World Back-Up Day. (March 31)

* Wed., March 31 - Last day of Calendar Year First Quarter. (March 31)

* Wed., March 31 - National Crayon Day. (March 31)

* Wed., March 31 (1851) - Anniversary: Jean Leon Foucault first demonstrates, to the general public, in the Pantheon in Paris, the Foucault Pendulum, which is a proof that the Earth rotates on its axis. He had invented the device on 1851 January 8 and first demonstrated it to scientists on 1851 February 3.
Near the end of his life, Jean Leon Foucault also developed the Siderostat-type Refractor Telescope. (March 31)

* Wed., March 31 (1918) - Anniversary: Daylight Saving Time (DST) established in the United States by the Standard Time Act, to conserve energy during World War I, after being promoted by Pittsburgh business and civic leader Robert Garland. However, DST was not popular, and the U.S. Congress repealed the law after the War. (March 31)

* Wed., March 31 (1949) - Anniversary: RCA Victor releases first 45-RPM (revolutions-per-minute) phonograph record format. (March 31)

Astronomical Calendar: 2021 April
Monthly Observances This Month

" April showers bring May flowers !"

Meteor Shower -
Lyrid: April 22

Moon Phases:
2021 * Today

Planets, Stars, Sky Events:
Today *** This Week
Solar System
Constellations *** Star Chart

Occultations:
Moon / Bright Stars
Moon / Bright Planet & Asteroid
Moon / Planets & Bright Stars
Major Planets & Moons

View International Space Station (ISS)
Rocket Launches This Month: Link 1 *** Link 2 *** Link 3 *** Link 4

Equinoxes (EQX), Solstices (SOLC), and Cross-Quarter (XQ) Days For This Year.
Chronological Cycles and Eras For This Year.
Dominical Letter: "C" - Used in a Perpetual Calendar. For Non-Leap Year of 2021.

Astronomical Glossary
of Terms Used

Astronomical Calendar
Archives

Other
Astronomical Calendars: Link 1 * Link 2

10,000-Year Calendar

Rise & Set Times

Current Sky Events & Astro Phenomena

News: Astronomy, Space, Science --

Weekly: SpaceWatchtower Blog

Daily: SpaceWatchtower Twitter Feed

History of Pittsburgh's Original
Buhl Planetarium and Institute of Popular Science

Astronomy Links

Science Links


a.m. = Ante-Meridiem (Morning: Midnight to a moment before Noon)

p.m. = Post-Meridiem (Afternoon & Evening: a moment after Noon to a moment before Midnight of the next day)

EST = Eastern Standard Time *** EDT = Eastern Daylight Saving Time *** UTC = Coordinated Universal Time

SPECIAL NOTES:
(1) All astronomical or sky observations are always weather-permitting.
(2) For calendar entries which describe a relationship between two or more celestial objects, unless otherwise noted all relationships between celestial objects are visual relationships as seen from Earth only.


* Nov. 1 to April 30 - Use of life jackets by every person on a small boat (less than 16 feet in length), during cold-weather months, is mandatory. (Nov. 1 to April 30)

* March 10 to April 12, September 24 through November 5 - Tsunami Preparedness Weeks. (mid-March through April, mid-September through early November)

* March 20 to April 11 - Annual National Cherry Blossom Festival, Washington DC. (~ Vernal Equinox to mid-April)

* March 27, local sunset to April 4, local sunset - Jewish holiday of Passover.

* March 28 to April 3 - National Week of the Ocean. (End of March, First Week of April)

* March 28 to April 5 - Holy Week. (Week of Palm Sunday through Holy Saturday; Traditionally, also including Easter Sunday, and possibly including Easter Monday)
Will Christians Agree to Fix the Date of Easter?

* March 29 to April 2 - National Retirement Planning Week®. (Early to mid-April)

* April 1 to 30 - National Kite Month. (April; plus in some years: some days in March and May)

* 2030 April 1 - U.S. Census Day - As required by the U.S. Constitution, the day once every ten years when a census is taken of all people living in the United States of America. (April 1 on years divisible by 10)

* Thur., April 1 - First day of calendar year Second Quarter. (April 1)

* Thur., April 1 - April Fools' Day - The end of a week-long (March 25 to April 1) New Year's festival in France during the Middle Ages, until January 1 was declared New Year's Day in 1564. After 1564, people in France who celebrated New Year's on April 1 were considered "April Fools." (April 1)

* Thur., April 1 - Maundy Thursday / Holy Thursday. (Thursday before Easter Sunday)
Will Christians Agree to Fix the Date of Easter?

* Thur., April 1 (1960) - Anniversary of launch of first successful weather satellite, TIROS-1. (April 1)
Also see: Space Race To Create Quantum Satellite.

* Thur., April 1 (1954) - Anniversary of first broadcast of educational television station WQED-TV 13 in Pittsburgh, the nation's first community-supported television station. (April 1)

* Fri., April 2 - Good Friday. (Friday before Easter Sunday)
Will Christians Agree to Fix the Date of Easter?

* Fri., April 2 (1968) - Anniversary: World Premiere of the very influential, science-fiction motion picture, 2001: A Space Odyssey, which was presented in many theaters, including Pittsburgh's Warner Theater, in "Cinerama," an early wide-screen format that preceded the Omnimax format. (April 2)

* Fri., April 2 - Light It Up Blue, in North America, is dedicated to raising awareness of autism (April 2) / World Autism Awareness Day. (April 2)

* Fri., April 2 - Reconciliation Day. (April 2)

* April 3 to 11 - National Robotics Week. (Early to mid-April)

* April 3 to 12, 8:00 to 10:00 p.m. Prevailing Local Time - CITIZEN SCIENCE - Annual Globe at Night campaign, to raise public awareness of the impact of light pollution by encouraging everyone everywhere to measure local levels of night sky brightness and contribute observations on-line to a world map.

* Sat., April 3 - Holy Saturday. (Saturday before Easter Sunday)
Will Christians Agree to Fix the Date of Easter?

* Sat., April 3 (1513) - Anniversary of the Discovery of Florida by Ponce de Leon. (April 3)

* Sat., April 3, 12:23 p.m. EDT / 16:23 UTC - Double-shadow (shadows of 2 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise.

* April 4 to 10 - National Library Week. (First, second, or third week of April)

* Sun., April 4 (Sunrise in Pittsburgh: 6:58 a.m. EDT / 10:58 UTC) - Easter Sunday. [46 days after Ash Wednesday; the first Sunday after the full moon (the Paschal Full Moon) following the March equinox (ecclesiastically, the equinox is reckoned to be on March 21, even though the equinox occurs, astronomically speaking, on March 20 in most years)]
Will Christians Agree to Fix the Date of Easter?

* Sun., April 4 (1968) - Anniversary: Assassination of American Baptist Minister and civil rights activist Dr. Martin Luther King, Jr. (April 4)
Dr. King's writing on how small the Earth is, compared to the great expanse of the Universe.

* Sun., April 4 - Land-Mine Awareness Day. (April 4)

* Sun., April 4 - Park Day - Annual hands-on preservation event to help Civil War — and now Revolutionary War — battlefields and historic sites take on maintenance projects large and small. (First Saturday of April)

* Sun., April 4, 2:00 a.m. Prevailing Local Time (Daylight Saving Time) - DAYLIGHT SAVING TIME CONTINUES - Change in Federal law, thus that change from Standard Time to Daylight Saving Time occured the second Sunday in March: 2:00 a.m. Standard Time then became 3:00 a.m. Daylight Saving Time on the second Sunday in March. (Previously, first Sunday of April)
Some States to Abandon Daylight Saving Time ?
Science of Daylight Saving Time.

* Sun., April 4, 6:02 a.m. EDT / 10:02 UTC - Primary Moon Phase: Last Quarter.

* April 5 to 12 - International Dark-Sky Week. (Week of the New Moon in April)

* April 5 to 11 - National Public Health Week. (First week of April)

* Mon., April 5 - Easter Monday. (Monday after Easter Sunday)
Will Christians Agree to Fix the Date of Easter?

* Tue., April 6 (2019) - Anniversary: GPS Week Number Roll-Over Event on Coordinated Universal Time (UTC) derived from GPS devices. The potential problem revolves around the way that GPS handles the week element of the data that forms part of the navigation signal; specifically the CNAV and MNAV message types. The week number is encoded into the data stream by a 10-bit field. A binary 10-bit word can represent a maximum of 1,024 weeks, which is approximately 19.7 years. Each 19.7 year period is known in GPS terms as an “epoch”. At the end of each epoch the receiver resets the week number to zero and starts counting again – a new epoch begins. The first epoch started when GPS was launched in January 1980; hence the first epoch of GPS time came to an end on 21st August 1999. As we approach the end of the second epoch, which will fall on 6th April 2019, we may well see problems caused by the rollover. Some GPS receivers, or other systems that utilise the date and time function, may not be able to cope. (April 6)

* Tue., April 6 (1965) - Anniversary: launch of Early Bird satellite (Intelsat I), first commercial communications satellite placed in a geo-stationary orbit above the Earth. (April 6)

* Tue., April 6 - National Library Workers Day. (Tuesday of National Library Week)

* Tue., April 6 (1917) - Anniversary: United States entry into World War I. (April 6)

* Tue., April 6 - Tartan Day - Celebration of Scottish heritage. (April 6)

* Tue., April 6, 4:00 a.m. EDT / 8:00 UTC - Saturn 4 degrees north of the Moon.

* Wed., April 7 - Global Day of the Engineer. (Early April: First Wednesday of April)

* Wed., April 7 - National Bookmobile Day. (Wednesday of National Library Week)

* Wed., April 7 - National Walking Day / Move More in April. (First Wednesday of April)

* Wed., April 7 - National Alcohol Screening Day (Early April: April 7)

* Wed., April 7 - No Housework Day. (April 7)

* Wed., April 7, 12:15 a.m. EDT / 4:15 UTC - Double-shadow (shadows of 2 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise.

* Wed., April 7, 1:42 a.m. EDT / 5:42 UTC - Double-shadow (shadows of 2 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise.

* Wed., April 7, 3:00 a.m. EDT / 7:00 UTC - Jupiter 4 degrees north of the Moon.

* Wed., April 7, 3:00 a.m. EDT / 7:00 UTC - Asteroid and Dwarf PlanetCeres in conjunction with the Sun (Ceres not visible, even with a telescope).

* Thur., April 8 (1920) - Anniversary: Death of Astronomer, Educator, and Maker of Telescopes and Precise Scientific Instruments, Dr. John A. Brashear. (April 8)

* Thur., April 8 (1960) - Anniversary: Project Ozma -The first major project in the Search for Extraterrestrial Intelligence (SETI), begun by National Radio Astronomy Observatory (NRAO) researcher Frank Drake pointing an 85-foot / 26-meter radio telescope dish at the NRAO facility at Green Bank, West Virginia toward Tau Ceti, a star similar to our Sun just 12 light-years away. (April 8)

* Thur., April 8 - Teen Literature Day. (Thursday of National Library Week)

* Thur., April 8 - Holocaust Remembrance Day. (27th day of Nisan on the Hebrew Calendar; corresponds to different dates, each year, on the Gregorian Calendar).

* Fri., April 9 (1865) - American Civil War ended with the surrender by Confederate General Robert E. Lee. (April 9)
Also see the Civil War Museum of the Andrew Carnegie Free Library and Music Hall in Carnegie, Pennsylvania.

* Fri., April 9, 3:42 a.m. EDT / 7:42 UTC - Launch of Soyuz MS-18 spacecraft, from the Baikonur Cosmodrome in Kazakhstan, bound for the International Space Station, with NASA astronaut Mark Vande Hei and two Russian cosmonauts, Oleg Novitsky and Pyotr Dubrov. The Week of the Young Child™. (Mid-April)

* April 10 to 17 - Money Smart Week®. (Mid-April)

* Sat., April 10 (1845) - Anniversary: The Great Pittsburgh Fire - While the Great Chicago Fire of 1871 is better known, this is a painting (1846) of the Great Pittsburgh Fire on 1845 April 10, by witness William Coventry Wall. Started on a very windy day by a woman who started an outdoor fire to heat wash water, which she had left unattended, the Great Pittsburgh Fire consumed one-third of this city of, then, more than 20,000 population (which already had four daily newspapers), representing around two-thirds of the wealth of the city (between $6 million and $12 million damage). While the fire destroyed 1,200 buildings and displaced 12,000 people, only two deaths were reported.

* Sat., April 10 (1996) - World record fastest wind gust on the Earth's surface (not related to a tornado) recorded by automated, unstaffed weather instrument station on Australia's Barrow Island during Tropical Cyclone Olivia: 253 miles per hour. (April 10)
Also see: Western and Northern Hemispheres' record fastest wind gust on the Earth's surface.

* Sat., April 10 - Be My Neighbor Day Volunteer Day in Pittsburgh. (2nd Saturday in April)

* Sat., April 10 - Siblings Day. (April 10)

* Sat., April 10, 3:01 p.m. EDT / 19:01 UTC - Double-shadow (shadows of 2 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise.

* April 11 to 17 - U.S. CFTC’s SmartCheck Week - To Emphasize Continual Background Checks of Financial Professionals. (Second week of April)

* April 11 to 17 - Pan American Week. (Week of April 14, Pan American Day)

* April 11 to 17 - National Dog-Bite Prevention Week. (Second full week of April)

* Sun., April 11 - NASA will conduct first test of Ingenuity helicopter flying over Mars, April 11 or later.

* Sun., April 11 - Good Deeds Day. (Sunday in late March or early to mid-April)

* Sun., April 11 - National Pet Day. (April 11)

* Sun., April 11, 10:30 p.m. EDT / April 12, 2:30 UTC - Primary Moon Phase: New Moon - Lunation #1216.

* Mon., April 12 (1961) - International Day of Human Space Flight - Anniversary of when Russia launched the first human into space and orbit of the Earth, Yuri Gagarin. (April 12)

* Mon., April 12 (1981) - First launch of an American Space Shuttle (STS), Columbia. (April 12)

* Mon., April 12 (1934) - World record fastest wind gust on the Earth's surface (not related to a tornado), until 1996 April 10, recorded at Mount Washington Weather Observatory, New Hampshire: 231 miles per hour. This is still the fastest wind gust on the Earth's surface (not related to a tornado) recorded in the Western Hemisphere and in the Northern Hemisphere, and the fastest wind gust on the Earth's surface (not related to a tornado) observed by humans. (April 12)
Also see: World record fastest wind gust on the Earth's surface.

* Mon., April 12 (1955) - Anniversary - Announcement: Successful polio vaccine, developed by University of Pittsburgh virology researcher Dr. Jonas Salk. (April 12)

* Mon., April 12 (1861) - The American Civil War began. (April 12)
Also see the Civil War Museum of the Andrew Carnegie Free Library and Music Hall in Carnegie, Pennsylvania.

* Mon., April 12 - Drop Everything and Read Day in honor of the birthday of children's author Beverly Cleary. (April 12)

* Mon., April 12, Sunset (In Pittsburgh - April 12 Sunset: 7:56 p.m. EDT / 23:56 UTC) - Commencement of the month of observance of Ramadan in the Islamic religion. The month lasts 29 to 30 days, dependent on visual sightings of the New Crescent Moon.

"> * Tue., April 13 - Citizen Science Day. (April 13)

* Tue., April 13 - Scrabble Day. (April 13)

* Tue., April 13 - FND International Awareness Day - Regarding Functional Neurological Symptom Disorder (FNsD). (April 13)

* Tue., April 13 (1970), 10:07:53 p.m. EST / April 14, 3:07:53 UTC
(SPECIAL NOTE: In 1970, Daylight Saving Time did not begin until April 26, the last Sunday in April.) -
Anniversary: Apollo 13 Accident.
Apollo 13 aborted mission to land on the Moon after an oxygen tank explosion severely crippled the spacecraft. After a 1970 April 11 launch, the three astronauts, James A. Lovell, John A. "Jack" Swigert, and Fred W. Haise, returned safely to Earth on 1970 April 17. Due to the plan to return Apollo 13 to Earth, after going around the Moon, the Apollo 13 astronauts flew farther from Earth than any other humans, to-date. (April 13)

* April 14 to 15 (1865) - Assassination of U.S. President Abraham Lincoln. (April 14 to 15)
Also see the Civil War Museum of the Andrew Carnegie Free Library and Music Hall in Carnegie, Pennsylvania.

* Wed., April 14 (1845) - First Light using a now-historic 11-inch Merz und Mahler Telescope at the Cincinnati Observatory, America's first public observatory. (April 14)

* Wed., April 14 - Pan American Day. (April 14)

* Wed., April 14, 4:21 a.m. EDT / 8:21 UTC - Double-shadow (shadows of 2 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise.

* Wed., April 14, 2:00 p.m. EDT / 18:00 UTC - Moon at apogee: 252,350.6 statute miles / 406,119 kilometers.

* Wed., April 14 (1970), 7:21 p.m. EST / April 15, 0:21 UTC
(SPECIAL NOTE: In 1970, Daylight Saving Time did not begin until April 26, the last Sunday in April.) -
Due to the Moon being nearly at apogee (farthest point in lunar orbit from the Earth, for month of 1970 April), the Apollo 13 astronauts became the first humans to travel farther from the Earth than any other humans, which is still true to-date; distance from Earth: 248,655 mile / 400,171 kilometers. This record was necessary, due to the abort of the lunar landing mission of Apollo 13. (April 14)

* Wed., April 14 (1912), 11:40 p.m. (Ship Time) - Anniversary of the sinking of the RMS Titanic on the ship's maiden voyage. (April 14)
Also see: Titanic Sunk by the Moon?

* Mid-April - Big Night for Spring Peepers - First night (or first several nights), after the ground has thawed, with temperatures ~ +40 to +50 degrees Fahrenheit (F), and it rains, when there is a massive migration of frogs and salamanders in New Hampshire and other New England states. (Mid-April)

* Thur., April 15 - SPECIAL NOTE: DEADLINE FOR FEDERAL TAX RETURNS EXTENDED TO MONDAY, 2021 MAY 17, DUE TO COVID-19 PANDEMIC EMERGENCY - Tax Day (USA) - Individual Federal tax returns due or postmarked by end of day. (April 15, unless delayed by a holiday)

* Thur., April 15 - Russian cosmonaut Sergey Ryzhikov hands-over command of the International Space Station to NASA astronaut Shannon Walker, who had arrived with the SpaceX Crew-1 mission in 2020 November, beginning ISS Expedition 65.

* Thur., April 15, 12:00 Noon LOCAL SUN TIME - In the middle of April of each year, Sundial Time and Local Clock Time are in general agreement, for locales which lie on a Time-Zone Meridian (such as Philadelphia, which lies on the Eastern Time Zone Meridian - or Greenwich, England, which lies on the Greenwich Time Zone Meridian or Prime Meridian). (~ April 15)

* April 16 to 22 - Earth Week. (Week leading to and including Earth Day, April 22: April 16 to 22)

* Fri., April 16 - National Healthcare Decisions Day. (April 16)

* Fri., April 16 - National Stress Awareness Day. (April 16)

* Fri., April 16 - World Voice Day. (April 16)

* Fri., April 16, 9:34 p.m. EDT / April 17, 1:34 UTC - Soyuz MS-17 spacecraft leaves International Space Station, with NASA astronaut Kate Rubins and Russian cosmonauts Sergey Ryzhikov and Sergey Kud-Sverchkov, scheduled to land near Dzhezkazgan, Kazakhstan, on April 17 at 12:57 a.m. EDT / 4:57 UTC.

* April 17 to 25 - National Park Week. (Third or fourth week of April, including both weekends)

* April 17, Nov. 26 - Record Store Day. (Second or third Saturday in April & Black Friday in November)

* Sat., April 17 - National Junior Ranger Day. (Saturday in National Park Week)

* Sat., April 17 - World Hemophilia Day. (April 17)

* Sat., April 17 - Blah, Blah, Blah Day. (April 17)

* Sat., April 17, 8:00 a.m. EDT / 12:00 UTC - Mars 0.1 degree north of the Moon; occultation: Africa (most of central and eastern sections, Middle East (southern section), India, Southeast Asia, Indonesia, Philippines (most of country).

* Sat., April 17, 8:00 p.m. EDT / April 18, 0:00 UTC - Moon 0.9 degree north of Open Star Cluster M35.

* April 18 to 24 - National Volunteer Week. (Mid-April)

* April 18 to 24 - National Sky Awareness Week (SAW), a week set-aside to “look up” and to see the myriad of cloud patterns and formations that grace the sky. (Last full week of April)

* April 18 to 24 - Preservation Week for library and archive materials. (Last week of April)

* April 18 to 24 - National Infertility Awareness Week®. (Last week of April)

* April 18 to 24 - Administrative Professionals Week. (Last full week of April)

* April 18 to 24 - National Re-entry Week. (Last week of April)

* April 18 to 24 - National Crime Victims' Rights Week. (Early to mid-April)

* April 18 to 24 - National Minority Cancer Awareness Week. (Third week of April)

* Sun., April 18 - Electrical Lineman Appreciation Day. (April 18)

* Sun., April 18, 10:00 p.m. EDT / April 19, 2:00 UTC - Mercury in superior conjunction with the Sun (Mercury not visible, even with a telescope).

* April 19 to 23 - National Environmental Education Week. (EE Week - Week near Earth Day: April 22)

* April 19 to 23 - Severe Weather Awareness Week. (Pennsylvania: Mid-April)

* Mon., April 19 (1965) - Anniversary: Commencement by WINS-AM 1010, New York City, of, what is now, the oldest continuously operating all-news radio station in the United States: Link 1 *** Link 2 (April 19)

* Mon., April 19 - Patriots' Day. (Third Monday of April)

* Tue., April 20 (1946) - Dissolution of the League of Nations; succeeded by the United Nations (UN), which was formed on 1945 October 24. (April 20)

* Tue., April 20, Evening - l World Night in Defence of the Starlight. (April 20, Evening)

* Tue., April 20, 2:59 a.m. EDT / 6:59 UTC - Primary Moon Phase: First Quarter.

* Wed., April 21 - Administrative Professionals Day. (Wednesday of Administrative Professionals' Week, last full week of April)

* Wed., April 21 - Generally, last day to expect frost in areas around +40 degrees north latitude, such as Pittsburgh. (April 21)

* Thur., April 22 (1970) - Anniversary: Earth Day. (April 22)

* Thur., April 22 (1994) - Anniversary - Announcement: Discovery of the Top Quark, the most massive of all observed elementary particles. (April 22)

* Thur., April 22 - National Take Our Daughters and Sons To Work Day. (Fourth Thursday of April)

* Thur., April 22, 6:11 a.m. EDT / 10:11 UTC - Launch of SpaceX Crew Dragon Crew-2 mission to the International Space Station, from Launch Complex 39A at NASA's Kennedy Space Center near Cape Canaveral, Florida, with NASA astronauts Shane Kimbrough and Megan McArthur, JAXA (Japan space agency) astronaut Akihiko Hoshide, and ESA (European Space Agency) astronaut Thomas Pesquet.

* Thur., April 22, 8:00 a.m. EDT / 12:00 UTC (Best viewing: Midnight to Dawn) - Peak of Lyrid Meteor Shower. (April 22)

* Fri., April 23 - World Book and Copyright Day / World Book Night. (April 23)

* Fri., April 23 - World Laboratory Day. (April 23)

* April 24 to 30 - World Immunization Week. (Last week of April: April 24 to 30)

* Sat., April 24 (1990) - Launch of Hubble Space Telescope (April 24).

* Sat., April 24 (1800) - Library of Congress established by an act of the U.S. Congress. (April 24)

* Sat., April 24 - Save the Frogs Day. (Last Saturday in April)
Also see news article.

* Sat., April 24 - World Healing Day. (Last Saturday of April)

* Sat., April 24, 10:00 a.m. to 2:00 p.m. Prevailing Local Time - National Prescription Drug Take-Back Day sponsored by the U.S. Drug Enforcement Administration. (Last Saturday in April)

* April 25 to May 2 - Orthodox Holy Week. (Week of Orthodox Palm Sunday through Orthodox Holy Saturday; Traditionally, also including Orthodox Easter Sunday)
Will Christians Agree to Fix the Date of Easter?

* April 25 to May 2 - National Infant Immunization Week (NIIW). (Mid-to-late April)

* Sun., April 25 - Orthodox Palm Sunday. (Sunday before Orthodox Easter Sunday)
Will Christians Agree to Fix the Date of Easter?

* Sun., April 25 (1953) - DNA Day - Commemorates the day in 1953 when James Watson, Francis Crick, Maurice Wilkins, Rosalind Franklin, and colleagues published papers in the journal Nature on the structure of DNA. (April 25)

* Sun., April 25 - World Penguin Day. (April 25)

* Sun., April 25 - World Malaria Day. (April 25)

* April 26 to 30 - National Work Zone Awareness Week. (Early to mid-April)

* Mon., April 26 (1920) - The 1920 Great Debate on the Scale of the Universe between Harlow Shapley of the Mount Wilson Observatory (who gave the keynote address at the 1941 dedication of the rather unique 10-inch Siderostat-Type Refractor Telescope at Pittsburgh's original Buhl Planetarium and Institute of Popular Science) and Allegheny Observatory Director Heber D. Curtis. (April 26)

* Mon., April 26 - World Intellectual Property Day. (April 26)

* Mon., April 26 - Help a Horse Day. (April 26)

* Mon., April 26, 11:31 p.m. EDT / April 27, 3:31 UTC - Primary Moon Phase: Full Moon - Pink Moon.

* Tue., April 27 - Mercury at perihelion.

* Tue., April 27, 3:00 a.m. EDT / 7:00 UTC - Mars 0.5 degree north of Open Star Cluster M35.

* Tue., April 27, 11:00 a.m. EDT / 15:00 UTC - Moon at perigee: 222,064.3939393925 statute miles / 357,378 kilometers.
Large tides along ocean coast-lines predicted, due to proximity to Full Moon phase late the previous evening.

* April 28 to May 6 (2001) - First Outer Space Tourist: Dennis Tito. (April 28 to May 6)

* April 28, 29 - Holocaust Remembrance Days (USA). (April 28, 29)

* Wed., April 28 - Orthodox Holy Wednesday. (Wednesday before Orthodox Easter Sunday)
Will Christians Agree to Fix the Date of Easter?

* Wed., April 28 - Workers' Memorial Day. (April 28)

* Thur., April 29 - Launch of Tianhe 1, the core module for the low-Earth orbit space station being constructed by China, using a Chinese Long March 5B rocket from the Wenchang Space Launch Center in China's Hainan province.

* Thur., April 29 - Orthodox Maundy Thursday / Holy Thursday. (Thursday before Orthodox Easter Sunday)
Will Christians Agree to Fix the Date of Easter?

* April 30, Sept. 30 - National PrepareAthon ! Day - Day to emphasize preparation for disasters and emergencies. (April 30, Sept. 30)

* Fri., April 30 - Arbor Day - National Arbor Day Foundation. (Last Friday of April)

* Fri., April 30 - Teach Children to Save Day. (Last Friday of April)

* Fri., April 30 - Orthodox Good Friday. (Friday before Orthodox Easter Sunday)
Will Christians Agree to Fix the Date of Easter?

* Fri., April 30 - International Jazz Day. (April 30)

* Fri., April 30, 4:00 p.m. EDT / 20:00 UTC - Uranus in conjunction with the Sun (Uranus not visible, even with a telescope).

* Sat., May 1 - Traditional Astronomical Cross-Quarter Day Beltaine, better known as May Day - Second traditional Astronomical Cross-Quarter Day of year; approximate mid-way point in Spring season. (May 1)
Actual Cross-Quarter Day.

* Wed., May 5, 2:36 p.m. EDT / 6:36 UTC - Actual Astronomical Cross-Quarter Day Beltaine, better known as May Day - Second traditional Astronomical Cross-Quarter Day of year; mid-way point in Spring season (~May 5-6).
Traditional Cross-Quarter Day.

Astronomical Calendar: 2021 May
Monthly Observances This Month

" April showers bring May flowers !"

SpaceX Crew Dragon Crew-1 Splash-down Scheduled May 2

Total Lunar Eclipse: May 26

Meteor Shower -
n-Aquarid (Eta Aquarid): May 4 to 7

Moon Phases:
2021 * Today

Planets, Stars, Sky Events:
Today *** This Week
Solar System
Constellations *** Star Chart

Occultations:
Moon / Bright Stars
Moon / Bright Planet & Asteroid
Moon / Planets & Bright Stars
Major Planets & Moons

View International Space Station (ISS)
Rocket Launches This Month: Link 1 *** Link 2 *** Link 3 *** Link 4

Equinoxes (EQX), Solstices (SOLC), and Cross-Quarter (XQ) Days For This Year.
Chronological Cycles and Eras For This Year.
Dominical Letter: "C" - Used in a Perpetual Calendar. For Non-Leap Year of 2021.

Science Experiments Children & Teens Can Do At Home !

Astronomical Glossary
of Terms Used

Astronomical Calendar
Archives

Other
Astronomical Calendars: Link 1 * Link 2

10,000-Year Calendar

Rise & Set Times

Current Sky Events & Astro Phenomena

News: Astronomy, Space, Science --

Weekly: SpaceWatchtower Blog

Daily: SpaceWatchtower Twitter Feed

History of Pittsburgh's Original
Buhl Planetarium and Institute of Popular Science

Astronomy Links

Science Links


a.m. = Ante-Meridiem (Morning: Midnight to a moment before Noon)

p.m. = Post-Meridiem (Afternoon & Evening: a moment after Noon to a moment before Midnight of the next day)

EST = Eastern Standard Time *** EDT = Eastern Daylight Saving Time *** UTC = Coordinated Universal Time

SPECIAL NOTES:
(1) All astronomical or sky observations are always weather-permitting.
(2) For calendar entries which describe a relationship between two or more celestial objects, unless otherwise noted all relationships between celestial objects are visual relationships as seen from Earth only.


* April 24 to May 1 - National Infant Immunization Week (NIIW). (Mid-to-late April)

* April 25 to May 2 - Orthodox Holy Week. (Week of Orthodox Palm Sunday through Orthodox Holy Saturday; Traditionally, also including Orthodox Easter Sunday)
Will Christians Agree to Fix the Date of Easter?

* April 28 to May 6 (2001) - First Outer Space Tourist: Dennis Tito. (April 28 to May 6)

* May 1 to 7 - Choose Privacy Week. (May 1 to 7)

* Sat., May 1 - Traditional Astronomical Cross-Quarter Day Beltaine, better known as May Day - Second traditional Astronomical Cross-Quarter Day of year; approximate mid-way point in Spring season. (May 1)
Actual Cross-Quarter Day.

* Sat., May 1 - Law Day. (May 1)

* Sat., May 1 - Loyalty Day. (May 1)

* Sat., May 1 - Orthodox Holy Saturday. (Saturday before Orthodox Easter Sunday)
Will Christians Agree to Fix the Date of Easter?

* Sat., May 1 - National Wildfire Community Preparedness Day. (First Saturday in May)

* Sat., May 1 - National Scrapbooking Day. (First Saturday in May)

* Sat., May 1 - National Comic Book Day. (First Saturday in May)

* Sat., May 1 (1971) - 50th Anniversary: National Railroad Passenger Corporation - Amtrak (original nickname: Railpax), America's national passenger railroad system: Link 1 *** Link 2. (May 1)

* May 2 to 8 - National Travel and Tourism Week. (First full week of May)

* May 2 to 8 - National Small Business Week. (End of April, beginning of May)

* May 2 to 8 - North American Occupational Safety and Health Week. (First full week of May)

* May 2 to 8 - Arson Awareness Week. (First full week of May)

* May 2 to 8 - National Travel and Tourism Week. (First full week of May)

* May 2 to 8 - National Small Business Week. (End of April, beginning of May)

* May 2 to 11, 8:00 to 10:00 p.m. Prevailing Local Time - CITIZEN SCIENCE - Annual Globe at Night campaign, to raise public awareness of the impact of light pollution by encouraging everyone everywhere to measure local levels of night sky brightness and contribute observations on-line to a world map.

* Sun., May 2 (Sunrise in Pittsburgh: 6:18 a.m. EDT / 10:18 UTC) - Orthodox Easter Sunday. [46 days after Orthodox Ash Wednesday; the first Sunday after the full moon (the Paschal Full Moon) following the March equinox (ecclesiastically, the equinox is reckoned to be on March 21, even though the equinox occurs, astronomically speaking, on March 20 in most years)]
Will Christians Agree to Fix the Date of Easter?

* Sun., May 2, 2:57 a.m. EDT / 6:57 UTC - Scheduled time of Spash-down of SpaceX Crew Dragon Crew-1 capsule in the Gulf of Mexico.
Watch Live!

* May 3 to 7 - Small Worlds Week - NASA celebrates the Solar System's two smallest planets: Mercury and Mars. (First school-week of May)

* May 3 to 7 - National PTA Teacher Appreciation Week. (First full school-week of May)

* May 3 to 9 - Children's Book Week (Last week of April and / or first week of May, beginning on Monday; Moved from 2007 Nov. 12 to 18; 2019: Centennial).

* May 3 to 9 - Public Service Recognition Week (PSRW). (First full week of May)

* Mon., May 3 - Sun Day. (May 3)

* Mon., May 3 - World Press Freedom Day (May 3).

* Mon., May 3 - Password Day. (May 3)

* Mon., May 3 (1971) - 50th Anniversary of the National Public Radio (NPR) news program, "All Things Considered" (ATC). (May 3)

* Mon., May 3 - National Day of Prayer. (~ May 3)

* Mon., May 3, 1:00 p.m. EDT / 17:00 UTC - Saturn 4 degrees north of the Moon.

* Mon., May 3, 3:50 p.m. EDT / 19:50 UTC - Primary Moon Phase: Last Quarter.

* Mon., May 3, 6:00 p.m. EDT / 22:00 UTC - Mercury 2 degrees south of the Pleiades Open Star Cluster.

* Tue., May 4 - "Star Wars" Day - "May the Fourth Be With You." (May 4)

* Tue., May 4 - Bird Day - Created in 1894 in the Western Pennsylvania community of Oil City. (May 4)

* Tue., May 4 - Greenery Day / Japan Arbor Day. (May 4)

* Tue., May 4 - World Asthma Day. (First Tuesday in May)

* Tue., May 4 - National Teacher Day. (Tuesday of Teacher Appreciation Week)

* Tue., May 4 - Give Local America Day to raise money for local non-profit organizations. (First Monday or Tuesday of May)

* Tue., May 4, 5:00 p.m. EDT / 21:00 UTC - Jupiter 5 degrees north of the Moon.

* Wed., May 5 - National Astronaut Day. (May 5)

* Wed., May 5 - Cinco de Mayo. (Mexico: May 5)

* Wed., May 5, 2:36 p.m. EDT / 6:36 UTC - Actual Astronomical Cross-Quarter Day Beltaine, better known as May Day - Second traditional Astronomical Cross-Quarter Day of year; mid-way point in Spring season (~May 5-6).
Traditional Cross-Quarter Day.

* Wed., May 5, 10:00 p.m. EDT / May 6, 2:00 UTC (Best viewing: Midnight to Dawn) - Peak of n-Aquarid (Eta Aquarid) Meteor Shower - remnants from Halley's Comet. (May 4 to 7)

* May 6 to 12 - National Nurses Week (from May 6, also known as National Nurses Day, through May 12, the birthday of Florence Nightingale, the founder of modern nursing).

* Thur., May 6 - National Nurses Day / National RN Recognition Day (May 6).

* Thur., May 6 - Read Your Farmers’ Almanac In The Bathroom Day. (May 6)

* Wed., May 6 - Bike to School Day. (First Wed. in May)

* Thur., May 6 - National Tourist Appreciation Day. (May 6)

* Fri., May 7 - International Space Day: Link 1 *** Link 2. (First Friday in May)

* Fri., May 7 - World Password Day. (May 7)

* May 8 to 16 - Armed Forces Week. [USA: Second Saturday to Sunday of following week in May (ends the fourth Sunday if the month begins on a Sunday, as in 2016)]

* Sat., May 8 - International Migratory Bird Day. (Second Saturday in May)

* Sat., May 8 - National Train Day. (Celebrated on the Saturday closest to the anniversary of the driving of the Golden Spike for the completion of the First Transcontinental Railroad in the United States of America: 1869 May 10)

* Sat., May 8 - Stamp-Out Hunger Food Drive. (Second Saturday of May)

* Sat., May 8 - World Fair Trade Day. (Second Saturday of May)

* Sat., May 8 (1828) - World Red Cross and Red Crescent Day. (May 8)

* Sat., May 8 (1945) - Victory in Europe Day. (May 8)

* May 9 to 15 - Bicycle Week / Bike-to-Work Week. (Second week of May)

* May 9 to 15 - Hurricane Preparedness Week. (Mid-May)

* May 9 to 15 - Women's Health Week. (Week that begins on Mothers' Day)

* May 9 to 15 - National Hospital Week (Second week of May)

* May 9 to 15 - Food Allergy Awareness Week (FAAW).

* Sun., May 9 - Mothers' Day. (Second Sunday in May)

* May 10 to 16 / Oct. 4 to 10 - International Astronomy Week. (Begins on the Monday preceding the Saturday designated as International Astronomy Day). (April or May / September or October)

* May 10 to 14 - Neuropathy Awareness Week. (Second full week of week-days in May)

* Mon., May 10 - Women's Checkup Day. (Monday after Mothers' Day - Monday of Women's Health Week)

* Mon., May 10 (1869) - Driving of the Golden Spike for the completion of the First Transcontinental Railroad in the United States of America. (May 10)

* May 11 to 16 - POSTPONED TO Oct. 13 to 17 - National Police Week. [Week including National Peace Officers' Memorial Day (May 15)]

* Tue., May 11, 3:00 p.m. EDT / 19:00 UTC - Primary Moon Phase: New Moon - Lunation #1217.

* Tue., May 11, 6:00 p.m. EDT / 22:00 UTC - Moon at apogee: 252,594.8461 statute miles / 406,512 kilometers.

* Wed., May 12 - National Lab Day. (May 12)

* Wed., May 12 - International Nurses Day, the birth date of pioneering nurse Florence Nightingale, and the end of the annual Nurses Week. (May 12)

* Wed., May 12 - National School Nurse Day. (Wednesday Of National Nurses Week)

* Wed., May 12 - National Student Nurses Day. (Wednesday Of National Nurses Week - originally May 8)

* Wed., May 12 - Limerick Day. (May 12)

* Wed., May 12, 6:00 p.m. EDT / 22:00 UTC - Venus 0.7 degree north of the Moon; occultation: majority of the islands of New Zealand, eastern portion of Polynesia, Easter Island.

* Thur., May 13 (1611) - “Galileo Confirmation Day,” anniversary of the day Jesuit priests held a banquet in honor of Galileo Galilei, for his discovery of four moons orbiting the planet Jupiter. (May 13)

* Thur., May 13 - Christian Feast of the Ascension. (Thursday: 40th day of Easter)

* Thur., May 13, 2:00 p.m. EDT / 18:00 UTC - Mercury 2 degrees north of the Moon.

* Fri., May. 14 - Wear Your Life-Jacket to Work Day. (Friday before the beginning of Safe Boating Week)

* May 15 to September 30 - Recreational Boating Season. (May 15 to Sept. 30)

* Saturday - May 15 / Oct. 9 - International Astronomy Day. [Saturday closest to First Quarter Primary Phase of the Moon, in April or May (Spring - Saturday of International Astronomy Week) and in September or October (Autumn)]: Link 1 *** Link 2 *** Link 3 *** Link 4

* Sat., May 15 - National Peace Officers' Memorial Day. (May 15)

* Sat., May 15 - International Day of Families. (May 15)

* Sat., May 15 - Armed Forces Day. (USA: Third Saturday in May)

* May 16 to 22 - Emergency Medical Services (EMS) Week. (Third full week of May)

* May 16 to 23 - Infrastructure Week. (MId-May)

* Sun., May 16 (Pittsburgh - Sunset: 8:31 p.m. EDT / May 17, 0:31 UTC) - Beginning of observance of Shavuot in the Hebrew religion. The observance, lasting two days, begins and ends at Sunset.

* Sun., May 16, 1:00 a.m. EDT / 5:00 UTC - Mars 1.5 degrees south of the Moon.

* May 17 to 21 - National Transportation Week / National Defense Transportation Week. [Week in which National Defense Transportation Day falls (Friday)]

* May 17 to 23 - National Tire Safety Week.[End of May (third week, Monday to Sunday) / Beginning of June]

* May 17 to 23 - National Etiquette Week.

* Thur., April 15 - SPECIAL NOTE: DEADLINE FOR FEDERAL TAX RETURNS EXTENDED TO MONDAY, 2021 MAY 17, DUE TO COVID-19 PANDEMIC EMERGENCY - Tax Day (USA) - Individual Federal tax returns due or postmarked by end of day. (April 15, unless delayed by a holiday)

* Tue., May 18 - International Museum Day. (May 18)

* Tue., May 18 - Visit Your Relatives Day. (May 18)

* Tue., May 18, 7:00 a.m. to 8:00 p.m. EDT / 11:00 UTC to May 19, 0:00 UTC - Primary Election Day: Pennsylvania (Third Tuesday in May except during Presidential Election Years when it is held on the Fourth Tuesday in April).

* Wed., May 19 - National May Ray Day This is a day to be outside, enjoying the sunshine and soaking up some rays from our nearest star. (May 19)

* Wed., May 19 - Emergency Medical Services for Children (EMSC) Day. [Wednesday of Emergency Medical Services (EMS) Week]

* Wed., May. 19 - Hepatitis Testing Day. (May 19)

* Wed., May. 19, 3:12 p.m. EDT / 19:12 UTC - Primary Moon Phase: First Quarter.

* Thur., May 20 (1877) - Anniversary: The Duquesne Incline cable car railway in Pittsburgh. (May 20)

* Thur., May 20 - Weights and Measures Day. (May 20)

* Thur., May 20 - Endangered Species Day. (May 20)

* Thur., May 20 - Food Revolution Day. (May 20)

* Thur., May 20 - Global Accessibility Awareness Day. (Third Thursday in May)

* Thur., May 20, 9:00 p.m. EDT / May 22, 1:00 UTC - NBC-TV - Red Nose Day / Comedy Day. (Third or fourth Thursday in May)

* May 21 to 28 - National Safe Boating Week in the beginning of the Recreational Boating Season. (First full week before Memorial Day Weekend)

* Fri., May. 21 - Wear Your Life-Jacket to Work Day. (Friday at beginning of, or before the beginning of, Safe Boating Week)

* Fri., May 21 - Bike-to-Work Day. (Third Friday in May)

* Fri., May 21 - National Defense Transportation Day. (Third Friday in May - Friday of National Defense Transportation Week)

* Fri., May 21 (1881) - Founding of the American Red Cross. (May 21)

* Fri., May 21 (1927) - Charles Lindbergh completes first solo trans-Atlantic flight and first non-stop flight between the Americas and main-land Europe, when landing in Paris in his Spirit of St. Louis airplane. (May 21)

* Fri., May 21 - World Day for Cultural Diversity for Dialogue and Development. (UN: May 21)

* Fri., May 21 - National Day of Service. (May 21)

* Sat., May 22 - National Maritime Day. (May 22)
Pittsburgh's original Buhl Planetarium and Institute of Popular Science displayed the largest Mercator's Projection Map of the World, originally produced by the U.S. Maritime Commission for display at the 1939 World's Fair in New York City.

* Sun., May 23 - World Turtle Day. (May 23)

* Sun., May 23 - World Crohn's and Colitis Day. (May 23)

* Sun., May 23 - "143" Day. "143" is short-hand created by Mister Rogers meaning "I love you."

* Sun., May 23, 11:15 a.m. EDT / 15:15 UTC - Double-shadow (shadows of 2 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise.

* May 24 to 30 - Camping & Caravanning Week. [End of May (last week) / Beginning of June]

* Mon., May 24 - Victoria Day - In Canada, informally considered the beginning of the Summer season. (Last Monday before May 25; the Monday between May 18 and 24)

* Tue., May 25 (1961) - Anniversary: When U.S. President John F. Kennedy, in a special speech before a joint session of the U.S. Congress, proposes a new national goal: "First, I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to the earth." (May 25)

* Tue., May 25 - National Missing Children's Day. (May 25)

* Tue., May 25, 10:00 p.m. EDT / May 26, 2:00 UTC - Moon at perigee: 222,022.76207 statute miles / 357,311 kilometers.
Large Tides predicted along ocean coast-lines, due to Full Moon phase just 9 hours and 14 minutes later.

* Wed., May 26 - National Senior Health & Fitness Day. (Last Wednesday in May)

* Wed., May 26, 7:14 a.m. EDT / 11:14 UTC - Primary Moon Phase: Full Moon - Flower Moon.
A so-called "Super-Moon" - the closest and, hence, largest Full Moon of 2021, due to lunar perigee just 9 hours and 14 minutes earlier.

* Wed., May 26, 7:18:43 a.m. EDT / 11:18:43 UTC - Time of greatest eclipse for Total Lunar Eclipse / Total Eclipse of the Moon, much of it visible throughout the Western Hemisphere as well as visible in central and eastern Asia and Australia. In the case of much of North America, the Moon will set and the Sun will rise in the middle of the eclipse. Areas which will see a "Super-Moon" Total Lunar Eclipse, with 14 minutes of totality, weather-permitting: Australia, parts of western North America, western South America, South-East Asia - Link 1 *** Link 2 *** Link 3 *** Link 4
ALWAYS SAFE TO LOOK AT A LUNAR ECLIPSE / ECLIPSE OF THE MOON WITH THE NAKED-EYES (ONE-POWER), BINOCULARS, OR A TELESCOPE.

* Thur., May 27, 12:29 p.m. Hawaii - Aleutian Standard Time (HAST) / 6:29 p.m. EDT / 22:29 UTC - Time in Honolulu, the state capital of Hawaii, of twice-annual Lāhainā Noon, the time when the Sun appears at the Zenith in the sky [directly overhead--with no solar shadow visible (weather-permitting)] at Local Solar Noon; Lāhainā Noon can only occur in the Tropics, in locations between the Tropic of Cancer and the Tropic of Capricorn on the world globe. (~May 27, ~July 16):
Link 1 *** Link 2.

* Fri., May 28 - Don't Fry Day - The National Council on Skin Cancer Prevention Encourages Sun Safety Awareness. (Friday before Memorial Day).

* Fri., May 28, 5:28 p.m. EDT / 21:28 UTC - Double-shadow (shadows of 2 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise.

* Sat., May 29 (1919) - Results from the 1919 May 29 Total Solar Eclipse experiment confirmed Albert Einstein's General Theory of Relativity. (May 29)

* Sat., May 29 - 529 College Savings Programs Day. (May 29)

* Sat., May 29, 2:00 a.m. EDT / 6:00 UTC - Mercury 0.4 degree south of Venus.

* Sat., May 29, 8:13 p.m. EDT / May 30, 0:13 UTC - Manhattan-Henge - View of Half Sun on the Manhattan, New York City, east--west street grid: Link 1 *** Link 2. (May 29, July 13)

* May 30 to June 5 - Black Birders Week. (End of May / Beginning of June)

* Sun., May 30 - Decoration Day. (USA: May 30)
Now observed as Memorial Day. (USA: Last Monday in May)

* Sun., May 30 (2020), 3:22:45 p.m. EDT / 19:22:45 UTC - Anniversary: FIRST PRIVATE CREWED SPACE LAUNCH - Launch (from historic Launch Pad 39A, Kennedy Space Center, Florida) of SpaceX Falcon 9 rocket with a Crew Dragon spacecraft to dock with the International Space Station (ISS); astronauts: Robert Behnken and Douglas Hurley:
Link 1 *** Link 2 *** Link 3 *** Link 4

* Sun., May 30, 8:12 p.m. EDT / May 31, 0:12 UTC - Manhattan-Henge - View of Full Sun on the Manhattan, New York City, east--west street grid: Link 1 *** Link 2. (May 30, July 12)

* Sun., May 30, 9:00 p.m. EDT / May 31, 1:00 UTC - Saturn 4 degrees north of the Moon.

* Mon., May 31 - Memorial Day. (USA: Last Monday in May)
Originally observed as Decoration Day. (USA: May 30)

* Mon., May 31 - World No Tobacco Day (WNTD). (May 31)

Astronomical Calendar: 2021 June
Monthly Observances This Month

Solar Eclipse / Eclipse of the Sun: June 10

Meteor Shower -- Arietid: peaks June 8.

Summer Solstice: June 20 to 22

Moon Phases:
2021 * Today

Planets, Stars, Sky Events:
Today *** This Week
Solar System
Constellations *** Star Chart

Occultations:
Moon / Bright Stars
Moon / Bright Planet & Asteroid
Moon / Planets & Bright Stars
Major Planets & Moons

View International Space Station (ISS)
Rocket Launches This Month: Link 1 *** Link 2 *** Link 3 *** Link 4

Equinoxes (EQX), Solstices (SOLC), and Cross-Quarter (XQ) Days For This Year.
Chronological Cycles and Eras For This Year.
Dominical Letter: "C" - Used in a Perpetual Calendar. For Non-Leap Year of 2021.

Science Experiments Children & Teens Can Do At Home !

Astronomical Glossary
of Terms Used

Astronomical Calendar
Archives

Other
Astronomical Calendars: Link 1 * Link 2

10,000-Year Calendar

Rise & Set Times

Current Sky Events & Astro Phenomena

News: Astronomy, Space, Science --

Weekly: SpaceWatchtower Blog

Daily: SpaceWatchtower Twitter Feed

History of Pittsburgh's Original
Buhl Planetarium and Institute of Popular Science

Astronomy Links

Science Links


a.m. = Ante-Meridiem (Morning: Midnight to a moment before Noon)

p.m. = Post-Meridiem (Afternoon & Evening: a moment after Noon to a moment before Midnight of the next day)

EST = Eastern Standard Time *** EDT = Eastern Daylight Saving Time *** UTC = Coordinated Universal Time

SPECIAL NOTES:
(1) All astronomical or sky observations are always weather-permitting.
(2) For calendar entries which describe a relationship between two or more celestial objects, unless otherwise noted all relationships between celestial objects are visual relationships as seen from Earth only.


* May 15 to September 30 - Recreational Boating Season. (May 15 to Sept. 30)

* May 30 to June 5 - Black Birders Week. (End of May / Beginning of June)

* June 1 to 7 - National CPR and AED Awareness Week. (June 1 to 7)

* June 1 to 10, 8:00 to 10:00 p.m. Prevailing Local Time - CITIZEN SCIENCE - Annual Globe at Night campaign, to raise public awareness of the impact of light pollution by encouraging everyone everywhere to measure local levels of night sky brightness and contribute observations on-line to a world map. (Monthly)

* Tue., June 1 - Beginning of Meteorological Season of Summer in Northern Hemisphere of Earth / Meteorological Season of Winter in Southern Hemisphere. (June 1)

* Tue., June 1 - Beginning of Hurricane Season in the Atlantic Ocean and Caribbean Sea. (June 1)

* Tue., June 1 - International Children's Day. (June 1)

* Tue., June 1 - Global Day of Parents. (June 1)

* Tue., June 1, 5:00 a.m. EDT / 9:00 UTC - Jupiter 5 degees north of the Moon.

* Tue., June 1 (1980), 5:00 p.m. EDT / 21:00 UTC - Anniversary: Beginning of 24 / 7 / 365 News Broadcasting on Cable Television - Cable News Network (CNN): Link 1 *** Link 2 (June 1)

* Wed., June 2 - Global Running Day. (First Wednesday of June)

* Wed., June 2 - National Gun Violence Awareness Day. (June 2)

* Wed., June 2, 3:24 a.m. EDT / 7:24 UTC - Primary Moon Phase: Last Quarter.

* Thur., June 3 - World Bicycle Day (UN). (June 3)

* June 4, 5, 6 - ASPCA National Pet Adoption Weekend. (First weekend of June)

* Fri., June 4 (1784) - French woman is first woman ride in a free-floating balloon. (June 4)

* Fri., June 4 - National Donut Day - Created by The Salvation Army in Chicago in 1938 to honor those of their members who served doughnuts to, "dough-boys", American soldiers in Europe during World War I. (First Friday of June)

* Fri., June 4, 7:22 p.m. EDT / 23:22 UTC - Double-shadow (shadows of 2 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise.

* Sat., June 5 - Reset the Net Day for privacy on the Internet. (June 5)

* Sat., June 5 - United Nations World Environment Day. (June 5)
( For 2010 United Nations World Environment Day Host City for North America: Pittsburgh.)

* Sat., June 5 - National Trails Day®. (First Saturday in June)

* Sat., June 5 - Name Tag Day. (First Saturday in June)
Pittsburgh Name Tag Day Event.

* June 6 to 12 - OSHA Safe and Sound Week. (Second week of June)

* June 6 to 12 - Work-Force Development Week. (Second week of June)

* Sun., June 6 (1944) - Anniversary: D-Day Allied invasion of Normandy during World War II. (June 6)

* Sun., June 6 (1968) - Anniversary: Assassination of U.S. Senator (D-NY) and Presidential Candidate Robert F. Kennedy. (June 6)

* Sun., June 6 - National Cancer Survivors Day®. (First Sunday in June)

* Sun., June 6, 6:00 p.m. EDT / 22:00 UTC - Asteroid 3 Juno at opposition (Juno visible, approx. local sunset to local sunrise, weather-permitting)

* Mon., June 7, 2:00 a.m. EDT / 6:00 UTC - Uranus 2 degrees north of the Moon.

* Mon., June 7, 10:00 p.m. EDT / June 8, 2:00 UTC - Moon at apogee: 252,418.37668 statute miles / 406,228 kilometers.

* Tue., June 8 - World Oceans Day. (June 8)

* Tue., June 8 (Best viewing: Midnight to Dawn) - Peak of Arietid Meteor Shower. (June 7 to 9)

* Thur., June 10 - Mercury at aphelion.

* Thur., June 10, 6:41:54 a.m. EDT / 10:41:54 UTC - Time of maximum eclipse for the Annular Solar Eclipse / Annular Eclipse of the Sun.
The Annular Solar Eclipse / Annular Eclipse of the Sun visible in portions of Russia (part of northeastern Siberia), northwestern Greenland, the North Pole, and eastern Canada (parts of the provinces of Ontario and Quebec, and the territory Nunavut).
A Partial Solar Eclipse / Partial Eclipse of the Sun visible in northern portions of Asia and Europe, as well as most of Canada, Alaska, and the northeastern United States.
Details: Link 1 *** Link 2 *** Link 3
Internet Live-Stream Web-Cast of 2021 June 10 Solar Eclipse / Eclipse of the Sun
NEVER LOOK DIRECTLY AT ANY SOLAR ECLIPSE / ECLIPSE OF THE SUN, UNLESS YOU HAVE THE PROPER EQUIPMENT AND PROPER TRAINING TO DO SO SAFELY !!!!
SOLAR ECLIPSE / ECLIPSE OF THE SUN: TIPS FOR SAFE VIEWING

* Thur., June 10, 6:52 a.m. EDT / 10:52 UTC - Primary Moon Phase: New Moon - Lunation #1218.

* Thur., June 10, 9:00 p.m. EDT / June 11, 1:00 UTC - Mercury in inferior conjunction with the Sun (Mercury not visible, even with a telescope).

* June 11 to 18 - Cephalopod Week highlighting sea creatures including squids and octopi. (Science Friday / National Public Radio: 3rd week of June, dating Friday to Friday)

* Fri., June 11 (1638; originally recorded as June 1 O.S. of the Julian Calendar) - First earthquake recorded in North America: New England / St. Lawrence Valley region. (June 11)

* Fri., June 11 (1997) - First photograph taken by a cellular telephone camera / Birth of Camera-Phone. (June 11)

* Fri., June 11, 10:39 p.m. EDT / June 12, 2:39 UTC - Double-shadow (shadows of 2 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise.

* Sat., June 12 - Venus at perihelion.

* Sat., June 12 - International NASH Day to raise awareness about non-alcoholic Steatohepatitis & Fatty Liver Disease. (June 12)

* Sat., June 12 - National Get Outdoors Day. (Second Saturday in June)

* Sat., June 12, 3:00 a.m. EDT / 7:00 UTC - Venus 1.5 degrees south of the Moon.

* June 13 to 19 - National Flag Week. (Week including Flag Day, June 14)

* June 13 to 19 - Fire-Fighter Safety Stand-Down Week / Fire and Emergency Services Safety and Health Week. (Third week of June)

* Sun., June 13 - National Children's Day. (Second Sunday in June)

* Sun., June 13, 4:00 p.m. EDT / 20:00 UTC - Mars 3 degrees south of the Moon.

* June 14 to 20 - Men's Health Week. (Week leading to and including Father's Day)

* Mon., June 14 (1777) - Flag Day - USA. Anniversary of date U.S. Congress adopted 13 stars and 13 stripes as the American flag; now flag includes 50 stars for each of the 50 states in the Union. (June 14)

* Mon., June 14 (1770) - Discovery of Lexell's Comet, by comet hunter Charles Messier, which became the closest comet to approach Earth in recorded history: Link 1 *** Link 2. (June 14)

* Mon., June 14 - At mid-northern latitudes (~40 degrees North Latitude, which is the latitude of Pittsburgh), earliest sunrise of the year (Pittsburgh - earliest sunrise: 5:49 a.m. EDT / 9:49 UTC). (June 14)

* Mon., June 14 - World Blood Donor Day. (June 14)

* Tue., June 15 (1215) - Anniversary of the Magna Carta, also known as The Great Charter of the Liberties of England, originally issued. (June 15)

* Wed., June 16 (1904) - Bloomsday - Commemoration and celebration of the life of Irish writer James Joyce, during which the events of his novel Ulysses (which is set on 1904 June 16) are relived. (June 16)

* Thur., June 17 - "Dump the Pump" Day, sponsored by the American Public Transportation Association and local public transit agencies nationwide, including Pittsburgh's Port Authority of Allegheny County. (Third Thursday in June)

* Thur., June 17 - Recess at Work Day. (Third Thursday in June)

* Thur., June 17, 11:54 p.m. EDT / June 18, 3:54 UTC - Primary Moon Phase: First Quarter.

* Fri., June 18 - Phi Day. (June 18)

* Fri., June 18 - Autistic Pride Day about shifting views of autism from "disease" to "difference." (June 18)

* Fri., June 18 - Wear Blue (Friday) Day to show their concern for the health and wellbeing of boys and men. (Friday of Men's Health Week / Friday before Fathers' Day)

* Fri., June 18 (1812) - Anniversary: Day the United States of America declared war on the British Empire, beginning the War of 1812. (June 18)

* Sat., June 19 (1865) - Juneteenth Independence Day commemorating the day in 1865 when the State of Texas abolished slavery, and more generally the end of slavery in the former Confederate States of America. (June 19)

* June 20 to 26 - Lightning Safety Awareness Week; see also Pittsburgh Post-Gazette article. (June)

* Sun., June 20 - International Sun-Day, a celebration of Astronomy and our planet's very important star, the Sun. (Sunday near the Summer Solstice)

* Sun., June 20 - Fathers' Day. (Third Sunday in June)

* Sun., June 20 - World Refugee Day. (June 20)

* Sun., June 20, 12:00 Noon Mountain Daylight Saving Time (MDT) / 2:00 p.m. EDT / 18:00 UTC - Summer Solstice Annual Event - Single beam of sunlight shines on a silver dollar embedded in the floor of the Art Museum at the University of Wyoming in Laramie, Wyoming. (June 20)

* Sun., June 20, 11:32 p.m. EDT / June 21, 3:32 UTC - Summer Solstice; Season of Summer begins in Earth's Northern Hemisphere / Season of Winter begins in Earth's Southern Hemisphere. (June 20 to 22)
Also see ---
** Solstice 24 Celebration special one-hour celebration (5:00 to 6:00 p.m. / 17:00 to 18:00 local time) for each of the Earth's 24 time zones.
** 1985 to 1991: Summer "Solstice Day" Annual Free Day at Buhl Planetarium.

* June 21 to 27 - National Pollinator Week. (Third or Fourth Week of June)

* Mon., June 21 - National Selfie Day. (June 21)

* Mon., June 21 (1948) - Columbia Records introduces 33 1/3-RPM (revolutions per minute), micro-groove LP (long-playing), vinyl record. (June 21)

* Mon., June 21 - Make Music Day music festivals around the world on or near the day of the Summer Solstice. (June 21)

* Mon., June 21 - International Day of Yoga. (June 21)

* Mon., June 21 - National Aboriginal Day - Canada. (June 21)

* Wed., June 23 {1868) - Date of patent for the first commercially successful typewriter. (June 23)

* Wed., June 23 - National Hydration (H2O) Day. (June 23)

* Wed., June 23 - United Nations Public Service Day. (June 23)

* Wed., June 23 - United Nations International Widows Day. (June 23)

* Wed., June 23, 6:00 a.m. EDT / 10:00 UTC - Moon at perigee: 223,666.28887 statute miles / 359,956 kilometers.

* Wed., June 23, 4:00 p.m. EDT / 20:00 UTC - Spectacular view of Mars in the foreground of the Beehive Open Star Cluster.

* June 24 (1947) & July 2 (1947) - Both dates are celebrated as World UFO Day for the first two well-publicized sightings / events regarding what has come to be known as Unidentified Flying Objects (UFOs) ---
** 1947 June 24: Sighting of 9 UFOs near Mount Rainier, Washington by businessman and private aircraft pilot Kenneth Arnold.
** 1947 July 2: Alleged crash, on the evening of 1947 July 4, of a UFO about 30-to-40 miles northwest of Roswell, New Mexico.
(June 24 & July 2)

* Thur., June 24 - Midsummer Day (Date of Summer Solstice in Roman times)
and St. Jean Baptiste Day / Quebec National Holiday. (June 24)

* Thur., June 24, 2:39 p.m. EDT / 18:39 UTC - Primary Moon Phase: Full Moon - Strawberry Moon.

* Fri., June 25 - Expected release of special report, by the U.S. Intelligence Community and U.S. Defense Department commissioned by the U.S. Congress, regarding Unidentified Aerial Phenomena (UAP) / Unidentified Flying Objects (UFOs).

* Fri., June 25, Late Evening (1638) - The first astronomical event recorded by native Europeans in continental North America was a total lunar eclipse on 1638 June 25 to 26. (June 25)
Also see information on the total lunar eclipse used by Christopher Columbus to scare natives into providing food and other provisions for his sailors: Link 1 *** Link 2.

* June 26 to 27 - Annual Ham / Amateur Radio Field Day weekend, sponsored in the United States by the American Radio Relay League (ARRL). When amateur radio operators test emergency radio equipment, operations, and procedures, which could be put in-use during hurricanes, tornadoes, or other public emergencies. (Always the fourth full weekend In June)
More information: Link 1 *** Link 2

* Sat., June 26 - Annual Pennsylvania Firefly Festival in the Allegheny National Forest near Tionesta, Pennsylvania, highlighting Synchronous Fireflies. (Fourth Saturday of June)

* Sat., June 26 (1974) - Introduction and first scanning of the Universal Product Code (UPC) bar-code, on a pack of Wrigley Company chewing gum. (June 26)

* Sat., June 26, 1:03 a.m. EDT / 5:03 UTC - Double-shadow (shadows of 2 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise.

* Sun., June 27 - At mid-northern latitudes (~40 degrees North Latitude, which is the latitude of Pittsburgh), latest sunset of the year (Pittsburgh - latest sunset: 8:54 p.m. EDT / June 28, 0:54 UTC). (June 27)

* Sun., June 27 (1967) - First Automatic Teller Machine (ATM) goes into use at Barclays Bank's Enfield Town Branch in North London, England. (June 27)

* Sun., June 27 - National HIV Testing Day (NHTD). (June 27)

* Sun., June 27, 5:00 a.m. EDT / 9:00 UTC - Saturn 4 degrees north of the Moon.

* Mon., June 28 - Tau Day - Day celebrating the value of 2Pi (~6.28), designated Tau, the ratio of a circle's circumference to its radius. (June 28)
More on Tau Day.

* Mon., June 28, 3:00 p.m. EDT / 19:00 UTC - Jupiter 4 degrees north of the Moon.

* June 30 to July 9, 8:00 to 10:00 p.m. Prevailing Local Time - CITIZEN SCIENCE - Annual Globe at Night campaign, to raise public awareness of the impact of light pollution by encouraging everyone everywhere to measure local levels of night sky brightness and contribute observations on-line to a world map. (Monthly)

* Wed., June 30 [June 17 O.S. (Old Calendar System / Julian Calendar) used in Russia at the time] (1908) - Anniversary of the Tunguska Blast caused by an air blast of large meteoroid or comet fragment. (June 30)

* Wed., June 30 - Asteroid Day - Annual global awareness movement that brings people from around the world together to learn about asteroids and what we can do to protect our planet, our families, communities, and future generations. Asteroid Day is held on the anniversary of the 1908 June 30 Siberian Tunguska event, the largest asteroid impact on Earth in recent history. (June 30)

* Wed., June 30 (1970) - Anniversary: First commercial video telephone call (AT&T Bell Labs "PicturePhone") between Pittsburgh Mayor Pete Flaherty and ALCOA Chairman and Chief Executive Officer John Harper occurred in Pittsburgh on the day before general customer PicturePhone service began, when 38 PicturePhones were in use at eight Pittsburgh companies, as well as Pittsburgh's news / talk radio station, NBC owned-and-operated WJAS-AM 1320 (which was involved in the video telephone service inauguration). Two public demonstration, PicturePhone booths were also installed on the Mezzanine of the original Buhl Planetarium and Institute of Popular Science (a.k.a. Buhl Science Center), Pittsburgh's science and technology museum from 1939 to 1991, as part of the museum's Bell Telephone exhibit. (June 30)
Link 1 *** Link 2 *** Link 3 *** Link 4 *** Link 5
More on the History of Video Telephone Service
Photograph of a PicturePhone Mod II, used during the 1970 roll-out of the commercial video telephone service.
PicturePhone Service depicted in the film, "2001: A Space Odyssey"

* Wed., June 30 - Social Media Day. (June 30)

* Wed., June 30 - Last day of calendar year Second Quarter. (June 30)

* Wed., June 30 - Last day of Fiscal Year - Pennsylvania. (June 30)

Astronomical Calendar: 2021 July
Monthly Observances This Month

Meteor Shower -- S. Delta-Aquarid: peaks July 27 to 29.

July 20: "Moon Day"
Anniversary: 1st Landing of Humans on Another Celestial Body - Earth's Moon !

Moon Phases:
2021 * Today

Planets, Stars, Sky Events:
Today *** This Week
Solar System
Constellations *** Star Chart

Occultations:
Moon / Bright Stars
Moon / Bright Planet & Asteroid
Moon / Planets & Bright Stars
Major Planets & Moons

View International Space Station (ISS)
Rocket Launches This Month: Link 1 *** Link 2 *** Link 3 *** Link 4

Equinoxes (EQX), Solstices (SOLC), and Cross-Quarter (XQ) Days For This Year.
Chronological Cycles and Eras For This Year.
Dominical Letter: "C" - Used in a Perpetual Calendar. For Non-Leap Year of 2021.

Science Experiments Children & Teens Can Do At Home !

Astronomical Glossary
of Terms Used

Astronomical Calendar
Archives

Other
Astronomical Calendars: Link 1 * Link 2

10,000-Year Calendar

Rise & Set Times

Current Sky Events & Astro Phenomena

News: Astronomy, Space, Science --

Weekly: SpaceWatchtower Blog

Daily: SpaceWatchtower Twitter Feed

History of Pittsburgh's Original
Buhl Planetarium and Institute of Popular Science

Astronomy Links

Science Links


a.m. = Ante-Meridiem (Morning: Midnight to a moment before Noon)

p.m. = Post-Meridiem (Afternoon & Evening: a moment after Noon to a moment before Midnight of the next day)

EST = Eastern Standard Time *** EDT = Eastern Daylight Saving Time *** UTC = Coordinated Universal Time

SPECIAL NOTES:
(1) All astronomical or sky observations are always weather-permitting.
(2) For calendar entries which describe a relationship between two or more celestial objects, unless otherwise noted all relationships between celestial objects are visual relationships as seen from Earth only.


* May 15 to September 30 - Recreational Boating Season. (May 15 to Sept. 30)

* June 30 to July 9, 8:00 to 10:00 p.m. Prevailing Local Time - CITIZEN SCIENCE - Annual Globe at Night campaign, to raise public awareness of the impact of light pollution by encouraging everyone everywhere to measure local levels of night sky brightness and contribute observations on-line to a world map. (Monthly)

* Tue., June 30, 11:00 p.m. EDT / July 1, 3:00 UTC - Mercury at inferior conjunction with the Sun (Mercury not visible, even with a telescope).

* July 1 to 3 (1863) - Anniversary of the Battle of Gettysburg, Pennsylvania of the American Civil War: Link 1 *** Link 2. (July 1 to 3)

* Wed., July 1 (1970) - Anniversary: Beginning of commercial video telephone service (AT&T Bell Labs "PicturePhone"), when 38 PicturePhones were in use at eight Pittsburgh companies, as well as Pittsburgh's news / talk radio station, NBC owned-and-operated WJAS-AM 1320 (which was involved in the video telephone service inauguration). Two public demonstration, PicturePhone booths were also installed on the Mezzanine of the original Buhl Planetarium and Institute of Popular Science (a.k.a. Buhl Science Center), Pittsburgh's science and technology museum from 1939 to 1991, as part of the museum's Bell Telephone exhibit. The very first commercial video telephone call came the previous day (1970 June 30), when Pittsburgh Mayor Pete Flaherty called ALCOA Chairman and Chief Executive Officer John Harper. (July 1)
Link 1 *** Link 2 *** Link 3 *** Link 4 *** Link 5
More on the History of Video Telephone Service
Photograph of a PicturePhone Mod II, used during the 1970 roll-out of the commercial video telephone service.
PicturePhone Service depicted in the film, "2001: A Space Odyssey"

* Thur., July 1 (1867) - Anniversary: Dominion Day / Canada Day. (Canada: July 1).

* Thur., July 1 - First day of Fiscal Year - Pennsylvania. (July 1)

* Thur., July 1 - First day of calendar year. Third Quarter (July 1)

* Thur., July 1, 5:10 p.m. EDT / 21:10 UTC - Primary Moon Phase: Last Quarter.

* Fri., July 2 - Mid-point of year. (July 2)

* June 24 (1947) & July 2 (1947) - Both dates are celebrated as World UFO Day for the first two well-publicized sightings / events regarding what has come to be known as Unidentified Flying Objects (UFOs) ---
** 1947 June 24: Sighting of 9 UFOs near Mount Rainier, Washington by businessman and private aircraft pilot Kenneth Arnold.
** 1947 July 2: Alleged crash, on the evening of 1947 July 4, of a UFO about 30-to-40 miles northwest of Roswell, New Mexico.
(June 24 & July 2)
ALSO SEE: 143 UFO Sightings, By U.S. Navy Pilots, Remain Unidentified

* July 3 to Aug. 11 (approx.) - "The Dog Days of Summer": Link 1 *** Link 2. (July 3 to Aug. 11)

* Sat., July 3 (1918) - Anniversary: Migratory Bird Treaty Act of 1918 (MBTA). (July 3)

* Sun., July 4 (1776) - American Independence Day - USA Independence Day, traditionally celebrated with fireworks. Link 1 *** Link 2. (U.S.A.: July 4)

* Sun., July 4 (1054) - Anniversary of observation of a "Guest Star" (i.e. supernova), which created what today is known as the Crab Nebula. Supernova SN 1054 was observed in China, Japan, Baghdad, and by the Anasazi Pueblo Peoples in New Mexico. This was the first recorded observation of a major astronomical event in North America. (July 4)

* Sun., July 4 (2012) - Anniversary: Public announcement at CERN (European Organization for Nuclear Research) of the discovery of the Higgs Boson, an elementary particle in the Standard Model of particle physics. (July 4)

* Sun., July 4, 11:00 a.m. EDT / 15:00 UTC - Uranus 2 degrees north of the Moon.

* Mon., July 5 - American Independence Day Observed - Official Federal observance of Independence Day, traditionally celebrated with fireworks. [July 5 (U.S.A.: 1776 July 4)]

* Mon., July 5 (1687) - Publication of Sir Isaac Newton's Principia, regarding gravitation. (July 5)

* Mon., July 5 - Global SUN-day. (July 5)

* Mon., July 5 - International Day of LGBTQ+ People in Science, Technology, Engineering, and Math (#LGBTSTEMDay). (July 5)

* Mon., July 5, 11:00 a.m. EDT / 15:00 UTC - Moon at apogee, farthest point in orbit from the Earth: 251,867.2 statute miles / 405,341 kilometers.

* Mon., July 5, 6:00 p.m. EDT / 22:00 UTC - Earth at aphelion, farthest point in orbit from the Sun: 94,510,885 statute miles / 152,100,527 kilometers. (Beginning of July)

* Tue., July 6 (1867) - First wedding taking place in a balloon - Mr. J. W. Smithson, of Philadelphia, and Miss Maggie E. Fornshell, of Wooster, Ohio, were married in a balloon over Pittsburgh. (July 6)

* Wed., July 7 - Beginning of the Japanese Star Festivals of Tanabata, which celebrates the meeting of the deities Orihime and Hikoboshi (represented by th e stars Vega and Altair respectively), which, according to legend, are kept separate by the Milky Way except once a year, on the seventh day of the seventh lunar month of the lunisolar calendar. (July 7)

* Wed., July 7 - Global Forgiveness Day. (July 7)

* Thur., July 8 - National Summer Learning Day. (2nd Thursday of July)

* Thur., July 8, 1:00 a.m. EDT / 5:00 UTC - Mercury 4 degrees south of the Moon.

* Fri., July 9, before Sunrise - Good time to look for Mercury, which reaches highest point in southeastern sky, just above horizon, brightly shining at apparent visual magnitude of +0.3.

* Fri., July 9, 9:16 p.m. EDT / July 10, 1:16 UTC - Primary Moon Phase: New Moon - Lunation # 1219.

* Sat., July 10 (1856) - Anniversary: Birth of physicist and electrical engineer Nikola Tesla, who helped George Westinghouse in Pittsburgh perfect the Alternating Current form of Electricity: Link 1 *** Link 2. (July 10)
Also see: Tesla Coil.

* Sun., July 11 (1767) - Anniversary: Birth of 6th U.S. President John Quincy Adams, America's Astronomy President. (July 11)

* Sun., July 11 - World Population Day. (United Nations: July 11)

* Sun., July 11 - All-American Pet Photo Day. (July 11)

* Mon., July 12, 5:00 a.m. EDT / 9:00 UTC - Venus 3 degrees south of the Moon.

* Mon., July 12, 6:00 a.m. EDT / 10:00 UTC - Mars 4 degrees south of the Moon.

* Mon., July 12, 8:20 p.m. EDT / July 13, 0:20 UTC - Manhattan-Henge - View of Full Sun on the Manhattan, New York City, east--west street grid: Link 1 *** Link 2. (July 12)

* Tue., July 13, 3:00 a.m. EDT / 7:00 UTC - Venus 0.5 degree north of Mars.

* Tue., July 13, 8:21 p.m. EDT / July 14, 0:21 UTC - Manhattan-Henge - View of Half Sun on the Manhattan, New York City, east--west street grid: Link 1 *** Link 2. (July 13)

* Wed., July 14 (1965) - First close-up photographs taken of another planet: Nauka science module NASA fly-by spacecraft Mariner 4, which flew-by Mars. (July 14)

* Wed., July 14 - Tape Measure Day (July 14)

* Wed., July 14 (1789) - Bastille Day / French National Day, which celebrates the Storming of the Bastille in Paris at the beginning of the French Revolution. (July 14)

* Thur., July 15 - St. Swithun's Day - According to tradition, the weather occurring on St. Swithun's Day will continue for forty days. This legend does have a scientific basis. At this time of year, for most years, the jet stream settles into a reasonably steady pattern until the end of August. (July 15)

* Thur., July 15, 1:16 p.m. EDT / 17:16 UTC - Launch of Russian Proton Rocket with the new Nauka Science Module for the International Space Station.

* Fri., July 16 (1958) - Anniversary: Both the U.S House of Representatives and the U.S. Senate approve the National Aeronautics and Space Act of 1958 (Pub.L. 85–568). (July 16)

* Fri., July 16 (1945), 5:29:21 a.m. Mountain War Time (MWT) / 7:29:21 a.m. Eastern War Time / 11:29:21 UTC (+ 2 seconds or - 2 seconds) -
Anniversary: First test, at the Trinity Site in New Mexico, of the first atomic bomb. (July 16)
Also see: Female Astrophysicist Helped Build 1st Atomic Bomb

* Fri., July 16 (1969), 9:32 a.m. EDT / 13:32 UTC - Anniversary: Launch of Apollo 11, the first mission to land two humans on the surface of Earth's Moon. (July 16)

* Fri., July 16, 12:38 p.m. Hawaii - Aleutian Standard Time (HAST) / 6:38 p.m. EDT / 22:38 UTC - Time in Honolulu, the state capital of Hawaii, of twice-annual Lāhainā Noon, the time when the Sun appears at the Zenith in the sky [directly overhead--with no solar shadow visible (weather-permitting)] at Local Solar Noon; Lāhainā Noon can only occur in the Tropics, in locations between the Tropic of Cancer and the Tropic of Capricorn on the world globe. (~May 27, ~July 16):
Link 1 *** Link 2.

* Sat., July 17 - World Emoji Day for computer / electronic communication. (July 17)

* Sat., July 17, 6:10 a.m. EDT / 10:10 UTC - Primary Moon Phase: First Quarter.

* Sat., July 17, 7:00 p.m. EDT / 23:00 UTC - Dwarf Planet Pluto at opposition (Pluto visible, with difficulty through telescope, approx. local sunset to local sunrise).

* Sun., July 18 - National Ice Cream Day. (3rd Sunday in July)

* Mon., July 19 - Dog Days of Summer: About 2200 years ago in Greece, date of the heliacal rising of Sirius; ancient mid-way point of "Dog Days of Summer": Link 1 *** Link 2. (July 19)

* Tue., July 20 (1969) - "Moon Day" - Anniversary ---
** July 20, 4:17:40 p.m. EDT / 20:17:40 UTC - Moment the Lunar Excursion Module (LEM - code-named "Eagle") landed on the Moon with astronauts Neil Armstrong and Buzz Aldrin.
** July 20, 10:56:20 p.m. EDT / July 21, 2:56:20 UTC - Moment the first human (Neil Armstrong) set foot on the Earth's Moon, during the NASA mission of Apollo 11: Link 1 *** Link 2. (July 20)
Special Note: Neil Armstrong was originally scheduled to first step on the Moon during the early morning hours of Monday ("Moonday"), July 21. Although this historic moment actually occurred earlier than scheduled, during the July 20 television prime-time in America, it actually did occur on "Moonday," July 21 at 2:56:20 Coordinated Universal Time (UTC), the time-scale used by many scientists.
Also see ---
** Launch of Apollo 11
** Personal remembrance of Apollo 11 mission
** American Lunar Society Founder on 50th Anniversary: 1st Humans Walk on Moon, KOKH’S QUESTION: After 50 Years, Why No Lunar Settlements ?

* Tue., July 20 - Space Exploration Day (July 20)

* Tue., July 20 (1976) - Anniversary: Landing of the NASA space probe, Viking 1, on the surface of Mars, the first U.S. spacecraft to safely land on the Red Planet: Link 1 *** Link 2. (July 20)
Also see: Special NASA radio reports to the public, regarding the Viking Mission to Mars.

* Wed., July 21 - Military Consumer Protection Day. (3rd Wednesday in July)

* Wed., July 21, 6:00 a.m. EDT / 10:00 UTC - Moon at perigee, closest point in orbit from the Earth: 226,502.2 statute miles / 364,520 kilometers.

* Wed., July 21, 3:00 p.m. EDT / 19:00 UTC - Venus 1.2 degrees north of star Regulus.

* Thur., July 22 - Pi Approximation Day, a holiday commemorating the mathematical constant π (pi). (July 22: 22 / 7)

* Thur., July 22 - National Intern Day. (4th Thursday of July)

* Fri., July 23, 12:28 p.m. EDT / 16:28 UTC - Docking of the new Russian Nauka Science Module with the International Space Station.

* Fri., July 23 - Hot Enough For Ya Day. (July 23)

* Fri., July 23, 10:37 p.m. EDT / July 24, 2:37 UTC - Primary Moon Phase: Full Moon - Buck Moon.

* Sat., July 24 - Mercury at perihelion, farthest point in orbit from the Sun.

* Sat., July 24 (1975) - End of "Space Race" between the United States and Russia (then known as the Union of Soviet Socialist Republics), which concluded with the Apollo (18) - Soyuz Test Project. (July 24)

* Sat., July 24 (1897) - Amelia Earhart Day, on the birthday of famous, pioneering female aviator Amelia Earhart. (July 24)

* Sat., July 24, 1:00 p.m. EDT / 17:00 UTC - Saturn 4 degrees north of the Moon

* July 25 to 31 - National Moth Week - CITIZEN SCIENCE project where citizen scientists can help map moth distributioWorld Day for Grandparents and the Elderlyn and provide needed information on other life history aspects around the globe. (Last full week of July)

* Sun., July 25 - "The Day Out of Time," the last day and extra day of the 13-Moon (each Moon or month consisting of 28 days), 364-day Mayan and "Galactic" year calendar: Link 1 *** Link 2. (July 25)

* Sun., July 25 - Parents' Day. (4th Sunday of July)

* Sun., July 25 - 1st Roman Catholic Church World Day for Grandparents and the Elderly. (4th Sunday in July).

* Sun., July 25, 9:00 p.m. EDT / July 26, 1:00 UTC - Jupiter 4 degrees north of the Moon.

* Mon., July 26 - First day of the 13-Moon (each Moon or month consisting of 28 days), 364-day "Galactic" year calendar, used for more than 5500 years by several cultures including the Maya, Inca, Druid, Egyptian, Essene, and the peoples of Polynesia. (July 26)

* Mon., July 26 (1990) - Anniversary: The Americans with Disabilities Act (ADA) signed into law by U.S. President George H.W. Bush: Link 1 *** Link 2 *** Link 3. (July 26)

* Mon., July 26 (1775) - United States Post Office established by decree of the Second Continental Congress, with Benjamin Franklin as first Postmaster General. (July 26)

* Tue., July 27 (1953) - Armistice ends fighting in United Nations police action in Korea. (July 27)

* Wed., July 28 - World Hepatitis Day. (July 28)

* Wed., July 28 (1914) - Commencement of World War I: Link 1 *** Link 2. (July 28)

* Thur., July 29 - Annual Rain Day in Waynesburg, Pennsylvania, about 50 statute miles / 80.4672 kilometers south of Pittsburgh. (July 29)

* Thur., July 29 (1958) - Anniversary: National Aeronautics and Space Administration (NASA) established by U.S. President Dwight D. Eisenhower, absorbing the former National Advisory Committee for Aeronautics (NACA: established 1915 March 3) with its Special Committee on Space Technology (established 1958 January 12): Link 1 *** Link 2. (July 29)

* Thur., July 29, 1:00 a.m. EDT / 5:00 UTC (Best viewing: Midnight to Dawn) - Peak of S. Delta-Aquarid Meteor Shower. (July 27 to 29)

* Thur., July 29, 12:00 Noon EDT / 16:00 UTC - Mars 0.7 degree north of star Regulus.

* Thur., July 29, 4:06 p.m. EDT / 20:06 UTC - Double-shadow (shadows of 2 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise.

* July 30 to Aug. 8, 8:00 to 10:00 p.m. Prevailing Local Time - CITIZEN SCIENCE - Annual Globe at Night campaign, to raise public awareness of the impact of light pollution by encouraging everyone everywhere to measure local levels of night sky brightness and contribute observations on-line to a world map. (Monthly)

* Fri., July 30 (1619) - First legislative assembly in America / New World convenes in Jamestown, Virginia. (July 30)

* Fri., July 30 - World Day against Trafficking in Persons. (July 30)

* Fri., July 30 - Father-in-Law Day.

* Fri., July 30, 2:53 p.m. EDT / 18:53 UTC - Launch (on a United Launch Alliance Atlas V Rocket) of Boeing's CST-100 Starliner OFT-2 mission to the International Space Station. This is the second launch attempt following a partial failure in December of 2019. There will be no crew on this mission.

* July 31 & Dec. 2 - National Mutt Day (July 31 & Dec. 2)

* Sat., July 31 - Dog Days of Summer: Rising of Sirius (the "Dog Star") ahead of the Sun (however, Sirius not visible until, at least, Aug. 7, due to glare of the Sun). (July 31)

* Sat., July 31 - Computer System Administrator Appreciation Day. (Last Friday in July)

* Sat., July 31, 9:16 a.m. EDT / 13:16 UTC - Primary Moon Phase: Last Quarter.

* Sat., July 31, 8:00 p.m. EDT / Aug. 1, 0:00 UTC - Uranus 1.8 degrees north of the Moon.

* Sun., Aug. 1 - Astronomical Mid-Point of Summer - Traditional Astronomical Cross-Quarter Day, also known as “Lammas” (in the United Kingdom) and “Lughnassad” (in Ireland). Considered approximate date of First Harvest (third traditional cross-quarter day of the year), approximately between the Midsummer Solstice and the Autumnal Equinox (July 31 Eve to Aug. 1).
Actual Cross-Quarter Day.

* Sat., Aug. 7, 2:53 a.m. EDT / 6:53 UTC - Astronomical Mid-Point of Summer - Actual Astronomical Cross-Quarter Day (halfway between the June Solstice and September Equinox: ~Aug. 6 to 7).
Traditional Cross-Quarter Day.

Astronomical Calendar: 2021 August
Monthly Observances This Month

Meteor Showers: Perseids - peaks Aug. 11 to 13; AMONG BEST OF YEAR !
Aurigids - peaks Sept. 1.

Moon Phases:
2021 * Today

Planets, Stars, Sky Events:
Today *** This Week
Solar System
Constellations *** Star Chart

Occultations:
Moon / Bright Stars
Moon / Bright Planet & Asteroid
Moon / Planets & Bright Stars
Major Planets & Moons

View International Space Station (ISS)
Rocket Launches This Month: Link 1 *** Link 2 *** Link 3 *** Link 4

Equinoxes (EQX), Solstices (SOLC), and Cross-Quarter (XQ) Days For This Year.
Chronological Cycles and Eras For This Year.
Dominical Letter: "C" - Used in a Perpetual Calendar. For Non-Leap Year of 2021.

Science Experiments Children & Teens Can Do At Home !

Astronomical Glossary
of Terms Used

Astronomical Calendar
Archives

Other
Astronomical Calendars: Link 1 * Link 2

10,000-Year Calendar

Rise & Set Times

Current Sky Events & Astro Phenomena

News: Astronomy, Space, Science --

Weekly: SpaceWatchtower Blog

Daily: SpaceWatchtower Twitter Feed

History of Pittsburgh's Original
Buhl Planetarium and Institute of Popular Science

Astronomy Links

Science Links


a.m. = Ante-Meridiem (Morning: Midnight to a moment before Noon)

p.m. = Post-Meridiem (Afternoon & Evening: a moment after Noon to a moment before Midnight of the next day)

EST = Eastern Standard Time *** EDT = Eastern Daylight Saving Time *** UTC = Coordinated Universal Time

SPECIAL NOTES:
(1) All astronomical or sky observations are always weather-permitting.
(2) For calendar entries which describe a relationship between two or more celestial objects, unless otherwise noted all relationships between celestial objects are visual relationships as seen from Earth only.


* May 15 to September 30 - Recreational Boating Season. (May 15 to Sept. 30)

* July 3 to Aug. 11 (approx.) - "The Dog Days of Summer": Link 1 *** Link 2. (July 3 to Aug. 11).

* July 30 to Aug. 8, 8:00 to 10:00 p.m. Prevailing Local Time - CITIZEN SCIENCE - Annual Globe at Night campaign, to raise public awareness of the impact of light pollution by encouraging everyone everywhere to measure local levels of night sky brightness and contribute observations on-line to a world map. (Monthly)

* July 31, August 1 & 2 (1971) - Anniversary: Apollo 15 astronauts Dave Scott and Pittsburgh native James B. Irwin became the seventh and eighth humans, respectively, to walk on the Moon.

* Sat., July 31 - Dog Days of Summer: Rising of Sirius (the "Dog Star") ahead of the Sun (however, Sirius not visible until, at least, Aug. 7, due to glare of the Sun). (July 31)

* Sat., July 31, 8:00 p.m. EDT / Aug. 1, 0:00 UTC - Uranus 1.8 degrees north of the Moon.

* Aug. 1 to 7 - Noctilucent Clouds - wispy-type clouds that shine at night, as they form as ice crystals around dust particles in Earth's atmosphere at the edge of space. This is the last week to get a good view of Noctilucent Clouds, as the length of daylight is now getting shorter each day, since the Summer Solstice. (Aug. 1 to 7)

* Aug. 1 to 7 - World Breast-Feeding Week (WBW). (Aug. 1 to 7)

* Aug. 1 to 7 - National Minority Donor Awareness Week. (Aug. 1 to 7)

* Aug. 1 to Aug. 7 - National Farmers Market Week. (First full week of August)

* Aug. 1 to Aug. 7 - National Stop on Red Week. (First full week of August)

* Sun., Aug. 1 (1818) - Anniversary: Birth of America's first female, professional astronomer, Maria Mitchell, who won a gold medal prize presented by the King of Denmark, for her discovery of a comet named in her honor: Miss Mitchell's Comet. (Aug. 1)
Also see: 1st U.S. Female Professional Astronomer: Leading Women's Suffragist

* Sun., Aug. 1 - Astronomical Mid-Point of Summer - Traditional Astronomical Cross-Quarter Day, also known as “Lammas” (in the United Kingdom) and “Lughnassad” (in Ireland). Considered approximate date of First Harvest (third traditional cross-quarter day of the year), approximately between the Midsummer Solstice and the Autumnal Equinox. (July 31 Eve to Aug. 1)
Actual Cross-Quarter Day.

* Sun., Aug. 1 - Lemonade Day in Western Pennsylvania, to teach children entrepreneurship and business.

* Sun., Aug. 1 - Friendship Day. (First Sunday in August)

* Sun., Aug. 1 - International Forgiveness Day. (First Sunday in August)

* Sun., Aug. 1 - National Sisters Day. (First Sunday in August)

* Sun., Aug. 1, 6:08 a.m. EDT / 10:08 UTC - Double-shadow (shadows of 2 of 4 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise, weather-permitting.

* Sun., Aug. 1, 10:00 a.m. EDT / 14:00 UTC - Mercury in superior conjunction with the Sun (Mercury not visible, even with a telescope).

* Mon., Aug. 2 (1955) - Space Race between the United States of America and the Union of Soviet Socialist Republics (now known as the Russian Federation) began in earnest, when the Soviet Union responded to the US announcement four days earlier of intent to launch artificial satellites for the International Geophysical Year, by declaring they would also launch a satellite "in the near future." (Aug. 2)

* Mon., Aug. 2 - Civic Holiday in certain Canadian provinces. (First Monday in August)

* Mon., Aug. 2, 2:00 a.m. EDT / 6:00 UTC - Saturn at opposition; Earth and Saturn closest for year. Saturn visible ~ local sunset to local sunrise, weather-permitting.

* Mon., Aug. 2, 4:00 a.m. EDT / 8:00 UTC - Moon at apogee; distance from Earth: 251,288.72385 statute miles / 404,410 kilometers.

* Tue., Aug. 3 - National Watermelon Day. (Aug. 3)

* Tue., Aug. 3 - Expected test launch of an un-crewed Boeing Starliner Capsule to the International Space Station (ISS). The launch was originally scheduled for July 30, but the launch was postponed at the last minute. The postponement was due to the ISS being thrown out-of-control by jet thrusters, which inadvertently activated following the addition of a new Russian space station module. Back-up launch date is August 4. The Boeing Starliner is another commercial spacecraft expected to transport NASA astronauts to the ISS, in addition to the SpaceX Crew Dragon.
Photograph of Boeing Starliner
NASA Live-Stream coverage of Starliner launch, now scheduled for Tuesday, 2021 August 3, 1:20 p.m. EDT / 17:20 UTC (Live-Stream coverage begins 12:30 p.m. EDT / 16:30 UTC):

* Tue., Aug. 3, Evening - National Night Out. (First Tuesday in August)

* Wed., Aug. 4 - Professional Engineers Day. (Aug. 4 ?)

* Fri., Aug. 6 - National Interview Day. (Aug. 6)

* Fri., Aug. 6 (1945), 8:15:43 a.m. Hiroshima Time (Japan Standard Time) / Aug. 5, 7:15:43 p.m. Eastern War Time / Aug. 5, 23:15:43 UTC -
Anniversary of the first war-time use of an Atomic Bomb over Hiroshima, Japan. (Aug. 6)
Also see: Female Astrophysicist Helped Build 1st Atomic Bomb

* Sat., Aug. 7, 2:53 a.m. EDT / 6:53 UTC - Astronomical Mid-Point of Summer - Actual Astronomical Cross-Quarter Day (halfway between the June Solstice and September Equinox: ~Aug. 6 to 7).
Traditional Cross-Quarter Day.

* Sat., Aug. 7 - National Lighthouse Day. (Aug. 7)

* Sat., Aug. 7 - Purple Heart Day. (Aug. 7)

* Aug. 8 to 14, after Sunset - International Starlight Week. (Week coinciding with annual Perseid Meteor Shower)

* Aug. 8 to 14 - National Health Center Week. (Second full week of August)

* Sun., Aug. 8 - International Cat Day. (Aug. 8)

* Sun., Aug. 8 (1786) - US Congress adopts silver dollar & decimal system of money. (Aug. 8)

* Sun., Aug. 8, 8:42 a.m. EDT / 12:42 UTC - Double-shadow (shadows of 2 of 4 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise, weather-permitting.

* Sun., Aug. 8, 9:50 a.m. EDT / 13:50 UTC - Primary Moon Phase: New Moon - Lunation #1220.

* Mon., Aug. 9 - Book Lovers Day. (Aug. 9)

* Mon., Aug. 9 (1945) - Anniversary: Second and last war-time use of an Atomic Bomb over Nagasaki, Japan. (Aug. 9)
Also see: Female Astrophysicist Helped Build 1st Atomic Bomb

* Mon., Aug. 9 (1944) - "Birthday": Smokey Bear - American campaign and advertising icon of the U.S. Forest Service for the Wildfire Prevention Campaign. (Aug. 9)

* Mon., Aug. 9 (1974) - Anniversary: First resignation of an American President. As a consequence of the Watergate Scandal, and prior to the U.S. House of Representatives approving three Articles of Impeachment of the President, the resignation of U.S. President Richard M. Nixon took effect at 12:00 Noon, after announcing his resignation on a nationally broadcast address the previous evening; recently appointed Vice President Gerald R. Ford, Jr. (who had been approved by the U.S. Senate for the appointment as Vice President after the resignation of Vice President Spiro T. Agnew) assumed the U.S. Presidency.
President Nixon's signature appears on the historic plaque left on the Moon at the site of the landing of the Lunar Excursion Module (LEM) of the Apollo 11 mission, where the first two humans set-foot on the Moon. President Nixon also spoke with NASA Astronauts Neil Armstrong and Buzz Aldrin, while they were on the Moon, in a conversation President Nixon called "the most historic phone call ever made from the White House." (Aug. 9)

* Mon., Aug. 9, local sunset - Islamic New Year Begins - Based on a Lunar Calendar.

* Tue., Aug. 10 (1846) - Founding of the Smithsonian Institution in Washington DC, originally from the bequest of British chemist James Smithson. The founding was spearheaded by Massachusetts Congressman and former U.S. President John Quincy Adams. (Aug. 10)
Samuel Pierpont Langley, second Director of Pittsburgh's Allegheny Observatory, became the third Secretary of the Smithsonian Institution, then considered the greatest scientific appointment in the nation.

* Tue., Aug. 10 - World Lion Day. (Aug. 10)

* Tue., Aug. 10 - Public Housing Health Centers Day. (Tuesday of National Health Center Week)

* Tue., Aug. 10, after Sunset - International Starry Night. (Aug. 10 - just before peak of annual Perseid Meteor Shower)

* Wed., Aug. 11 - For +40 degrees North Latitude (Latitude of Pittsburgh), annual Heliacal Rising of the Star Sirius (Dog Star), the brightest star in the night sky, the first time Sirius can be seen in the morning sky for the year. In ancient times, the Heliacal Rising of Sirius coincided with the flooding of the Nile River, which was and still is Egypt's life-line; the Heliacal Rising of Procyon (Little Dog Star), which annually occurred a little ahead of the Heliacal Rising of Sirius, gave the ancients extra warning for the soon-Heliacal Rising of Sirius. At that time, it was thought that the heat from the brightest star (Sirius), rising near the same time as the rising of the Sun, contributed to the great heat of the Summer Season. (Aug. 11)

* Wed., Aug. 11 (1919) - Anniversary: Death of industrialist and philanthropist Andrew Carnegie, who helped build 2,509 public libraries, Allegheny Observatory, 11-inch Brashear Refractor Telescope for original Carnegie Institute of Technology observatory, Mount Wilson Observatory, Carnegie Institution of Science, Carnegie Technical Schools (now Carnegie Mellon University), Carnegie Museum of Natural History (including Dinosaur Hall, which Andrew Carnegie funded and promoted). (Aug. 11)

* Wed., Aug. 11 - Health Care for the Homeless Day. (Wednesday of National Health Center Week)

* Wed., Aug. 11, 3:00 a.m. EDT / 7:00 UTC - Venus 4 degrees south of the Moon.

* Wed., Aug. 11, 2:00 p.m. EDT / 18:00 UTC - Mercury 1.2 degrees north of star Regulus.

* Thur., Aug. 12 (1981) - Anniversary: Introduction of IBM Personal Computer (PC). (Aug. 12)

* Thur., Aug. 12 - World Elephant Day. (Aug. 12)

* Thur., Aug. 12 - International Youth Day. (Aug. 12)

* Thur., Aug. 12 - Middle Child's Day. (Aug. 12)

* Thur., Aug. 12 - Farmworker Health Day. (Thursday of National Health Center Week)

* Thur., Aug. 12, 3:00 p.m. EDT / 19:00 UTC (Best viewing: Aug. 11, 12, & 13, Midnight to Dawn) - Peak of Perseid Meteor Shower, considered one of the best of the year! (Aug. 11 to 13).
Also see: NASA: Perseid Meteor Shower Has Most Fireballs.

* Aug. 13, 14, 15 weekend and September 10, 11, 12 weekend, 30 minutes before sunset - A Swift Night-Out - CITIZEN SCIENCE PROJECT to observe bird roosts of Chimney Swifts and Vaux's Swifts.
More on Citizen Science & Chimey Swifts. (Second Weekend August and September: Friday, Saturday, Sunday)

* Fri., Aug. 13 - "Friday the 13th" superstition; debunking this superstition, purpose of character King Friday the 13th on popular PBS children's television series, Mister Rogers' Neighborhood (originated at WQED-TV channel 13 in Pittsburgh). (Friday the 13th)

* Fri., Aug. 13 - International Lefthanders Day. (Aug. 13)

* Sun., Aug. 15 (1877) - Anniversary of Establishment of Telephone Greeting "Hello" - In preparation for introduction of the telephone in the city of Pittsburgh, in an unpublished letter from Thomas A. Edison to T.B.A. David, President of Pittsburgh's Central District and Printing Telegraph Company, Mr. Edison suggested "I don't think we shall need a call bell as Hello! can be heard 10 to 20 feet away." (Aug. 15)

* Sun., Aug. 15 (1945) - Anniversary - Announcement: Surrender of Japan and end of World War II (Aug. 15).
Victory Over Japan Day (United Kingdom) - Day of initial announcement of Japan surrender ending World War II. (Aug. 15)
Celebrated on September 2 in USA, for formal surrender on Battleship USS Missouri.

* Sun., Aug. 15 - Relaxation Day. (Aug. 15)

* Sun., Aug. 15, 5:39 a.m. EDT / 9:39 UTC - Dog Days of Summer: First visible (Sirius rises ahead of Sun at 7 degrees altitude) Heliacal rising of Sirius; modern mid-way point in "The Dog Days of Summer". (~ Aug. 7 to 15)

* Sun., Aug. 15, 10:41 a.m. EDT / 14:41 UTC - Double-shadow (shadows of 2 of 4 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise, weather-permitting.

* Sun., Aug. 15, 11:17 a.m. EDT / 15:17 UTC - Double-shadow (shadows of 2 of 4 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise, weather-permitting.

* Sun., Aug. 15, 11:19 a.m. EDT / 15:19 UTC - Primary Moon Phase: First Quarter.

* Sun., Aug. 15, 11:31 a.m. EDT / 15:31 UTC - TRIPLE-shadow (shadows of 3 of 4 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise, weather-permitting.

* Mon., Aug. 16 - Rollercoaster Day. (Aug. 16)

* Tue., Aug. 17 - Black Cat Appreciation Day. (Aug. 17)

* Tue., Aug. 17 - National Thriftshop Day. (Aug. 17)

* Tue., Aug. 17, 5:00 a.m. EDT / 9:00 UTC - Moon at perigee; distance from Earth: 229,363.01996 statute miles / 369,124 kilometers.

* Wed., Aug.18 - Serendipity Day. (Aug. 18)

* Thur., Aug. 19 (1871) - National Aviation Day, anniversary of the 1871 birth of Orville Wright, who with brother Wilbur, is credited with the first powered flight of a man. (Aug. 19)

* Thur., Aug. 19 (1839) - World Photography Day - Anniversary of the release of the first practical photographic process patent. (Aug. 19)

* Thur., Aug. 19 - World Humanitarian Day. (Aug. 19)

* Thur., Aug. 19, 12:00 Midnight EDT / 4:00 UTC - Mercury 0.1 degree south of Mars.

* Thur., Aug. 19, 8:00 p.m. EDT / Aug. 20, 0:00 UTC - Jupiter at opposition; Earth and Jupiter closest for year. Jupiter visible ~ local sunset to local sunrise, weather-permitting.

* Aug. 20, 21, 22 - Pledge to Fledge ! campaign for birders to share their love and information about the birding hobby with others. (Third weekend in August)

* Fri., Aug. 20 (1920) - National Radio Day. (Aug. 20)
This was the day, in 1920, when The Detroit News-owned amateur radio station 8MK began regular broadcasting; today, this station is all-news WWJ-AM 950. (Aug. 20)

* Fri., Aug. 20 (1619) - Beginning of slavery in North America with the first African slaves arriving in Jamestown, Virginia. (Aug. 20)

* Fri., Aug. 20, 6:00 p.m. EDT 22:00 UTC - Saturn 4 degrees north of the Moon.

* Sat., Aug.21 - World Honey Bee Day. (3rd Saturday in August)

* Sat., Aug.21 - Clear the (Animal) Shelters Day. (3rd Saturday in August)

* Aug. 22 to 28 - National Book Week Australia. (Last week of August)

* Sun., Aug. 22, 1:00 a.m. EDT / 5:00 UTC - Jupiter 4 degrees north of the Moon.

* Sun., Aug. 22, 8:02 a.m. EDT / 12:02 UTC - Primary Moon Phase: Full Moon - Sturgeon Moon.

* Sun., Aug. 22, 2:42 p.m. EDT / 18:42 UTC - Double-shadow (shadows of 2 of 4 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise, weather-permitting.

* Mon., Aug. 23 (1991) - Internaut Day - Anniversary, in 1991, of the Internet's World Wide Web (www). (Aug. 23)

* Mon., Aug. 23 - Health Unit Coordinator Day. (Aug. 23)

* Mon., Aug. 23 - International Day for the Remembrance of the Slave Trade and its Abolition. (Aug. 23)

* Tue., Aug. 24 (A.D. 79) - Historic eruption of Mount Vesuvius, in what is now Italy, which resulted in the destruction and burying of Pompeii and Herculaneum, among other settlements. (Aug. 24)

* Aug. 25 to 31 - Black Breast-Feeding Week. (Aug. 25 to 31)

* Wed., Aug. 25 - World Doctorates Day. (Aug. 25)

* Wed., Aug. 25 (1916) - Anniversary (1916: Centennial): Establishment of the United States Department of the Interior's National Park Service. (Aug. 25)

* Wed., Aug. 25 - National Kiss and Make-Up Day. (Aug. 25)

* Thur., Aug. 26 (1920) - Anniversary: Women's Equality Day - Certification of 19th Amendment to the United States Constitution, granting women the right to vote. (Aug. 26)

* Thur., Aug. 26 - National Dog Day & International Dog Day. (Aug. 26)

* Fri., Aug. 27 (1883) - Historic eruption of the Krakatoa Volcano in the Dutch East Indies (now Indonesia). (Aug. 27)
Loudest sound heard by man, in recorded history.

* Fri., Aug. 27 - Global Forgiveness Day. (Aug. 27)

* Sat., Aug. 28 (1912) - Anniversary: New Allegheny Observatory building, in Pittsburgh's Riverview Park, dedicated. (Aug. 28)

* Sat., Aug. 28, 5:00 a.m. EDT / 9:00 UTC - Uranus 1.5 degrees north of the Moon.

* Aug. 29 to Sept. 7, 8:00 to 10:00 p.m. Prevailing Local Time - CITIZEN SCIENCE - Annual Globe at Night campaign, to raise public awareness of the impact of light pollution by encouraging everyone everywhere to measure local levels of night sky brightness and contribute observations on-line to a world map. (Monthly)

* Sun., Aug. 29, 6:43 p.m. EDT / 22:43 UTC - Double-shadow (shadows of 2 of 4 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise, weather-permitting.

* Sun., Aug. 29, 10:00 p.m. EDT / Aug. 30, 2:00 UTC - Moon at apogee: 251,096.09878 statute miles / 404,100 kilometers.

* Sun., Aug. 30 (1955) - De-facto beginning date of the "Space Race" between the United States of America and the Union of Soviet Socialist Republics (now known as the Russian Federation) - when the Soviet Academy of Sciences created a commission whose purpose was to beat the Americans into Earth orbit.. (Aug. 30)

* Mon., Aug. 30 - Grief Awareness Day. (Aug. 30)

* Mon., Aug. 30 - International Day of the Disappeared. (Aug. 30)

* Mon., Aug. 30, 3:13 a.m. EDT / 7:13 UTC - Primary Moon Phase: Last Quarter.

* Tue., Aug. 31 - International Overdose Awareness Day (IOAD). (Aug. 31)

* Tue., Aug. 31 (1991), 5:00 p.m. EDT / 21:00 UTC - Anniversary: Closing of The Buhl Planetarium and Institute of Popular Science (a.k.a. original Buhl Science Center) as a public museum in Pittsburgh, which was dedicated as America's fifth major planetarium on 1939 October 24. (Aug. 31)

* Wed., Sept. 1 (Best viewing: Midnight to Dawn) - Peak of Aurigid Meteor Shower. (Sept. 1)

Astronomical Calendar: 2021 September
Monthly Observances This Month

Sept. 15: 1st All-Civilian SpaceX Launch

Sept. 22 or 23 - Autumnal Equinox: Autumn Begins

Meteor Shower -- Aurigids: peaks Sept. 1.

WHY LEAVES
CHANGE COLOR

Autumn Foliage Reports --
Foliage Network Reports
Weather Ch. Viewing Maps
National Forests
New England
PA * WV * OH * MD

Moon Phases:
2021 * Today

Planets, Stars, Sky Events:
Today *** This Week
Solar System
Constellations *** Star Chart

Occultations:
Moon / Bright Stars
Moon / Bright Planet & Asteroid
Moon / Planets & Bright Stars
Major Planets & Moons

View International Space Station (ISS)
Rocket Launches This Month: Link 1 *** Link 2 *** Link 3 *** Link 4

Equinoxes (EQX), Solstices (SOLC), and Cross-Quarter (XQ) Days For This Year.
Chronological Cycles and Eras For This Year.
Dominical Letter: "C" - Used in a Perpetual Calendar. For Non-Leap Year of 2021.

Astronomical Glossary
of Terms Used

Astronomical Calendar
Archives

Other
Astronomical Calendars: Link 1 * Link 2

10,000-Year Calendar

Rise & Set Times

Current Sky Events & Astro Phenomena

News: Astronomy, Space, Science --

Weekly: SpaceWatchtower Blog

Daily: SpaceWatchtower Twitter Feed

History of Pittsburgh's Original
Buhl Planetarium and Institute of Popular Science

Astronomy Links

Science Links


a.m. = Ante-Meridiem (Morning: Midnight to a moment before Noon)

p.m. = Post-Meridiem (Afternoon & Evening: a moment after Noon to a moment before Midnight of the next day)

EST = Eastern Standard Time *** EDT = Eastern Daylight Saving Time *** UTC = Coordinated Universal Time

SPECIAL NOTES:
(1) All astronomical or sky observations are always weather-permitting.
(2) For calendar entries which describe a relationship between two or more celestial objects, unless otherwise noted all relationships between celestial objects are visual relationships as seen from Earth only.


* May 15 to September 30 - Recreational Boating Season. (May 15 to Sept. 30)

* Aug. 29 to Sept. 7, 8:00 to 10:00 p.m. Prevailing Local Time - CITIZEN SCIENCE - Annual Globe at Night campaign, to raise public awareness of the impact of light pollution by encouraging everyone everywhere to measure local levels of night sky brightness and contribute observations on-line to a world map. (Monthly)

* Sept. 1 to 30, Each Evening - Vaux’s Swifts Watch at Chapman School, Portland, Oregon - Public can view a spectacular display of Vaux’s Swift birds as they gather to roost in the school’s chimney. Volunteers from Portland Audubon will be present each night with information about the swifts, binoculars and a spotting scope for viewing. (Sept. 1 to 30)

* Sept. 1 to 2 (1859) - Anniversary: Carrington Event - Major Solar Storm of 1859 - English Amateur Astronomer Richard C. Carrington observed a Solar Flare, which is associated with a major Coronal Mass Ejection (CME) which caused the Carrington Event, just before 12:00 Noon on 1859 September 1. This was one of the first known geomagnetic storms to have major affects on Earth, 1859 September 1 to 2, including great auroral displays and caused severe disruptions with electrical telegraph systems (some telegraph systems actually caught fire). Such a solar storm today could bring down electrical grids (which did happen in Quebec in March of 1989), severely disrupt radio communications, and destroy the electronics in satellites. In fact, a Carrington-Class Solar Super Storm did occur on the Sun on 2012 July 23, although the CME missed the Earth. (Sept. 1 to 2)

* Wed., Sept. 1 - Beginning of Meteorological Season of Autumn in the Northern Hemisphere (Sept. 1) .

* Wed., Sept. 1 - Beginning of Spring Season in Australia. (Sept. 1)

* Wed., Sept. 1 - . Mid-point in Atlantic Ocean Hurricane Season. (Sept. 1)

* Wed., Sept. 1 (1914) - Anniversary: Passing of Martha in the Cincinnati Zoo, the last Passenger Pigeon, marking the extinction of the species, due to hunting and habitat destruction. Also see Project Passenger Pigeon. (Sept. 1)

* Wed., Sept. 1 (1939) - Anniversary: Beginning of World War II. (Sept. 1)

* Wed., Sept. 1 (2017) - Anniversary: Asteroid 3122 Florence (named in honor of Florence Nightingale, the founder of modern nursing) passes within 4.4 million miles / 7 million kilometers of Earth (18 times the distance between the Earth and the Moon). The largest asteroid to pass Earth since NASA started tracking asteroids, this asteroid measures 2.7 miles in diameter. (Sept. 1)

* Wed., Sept. 1 (Best viewing: Midnight to Dawn, weather-permitting) - Peak of Aurigid Meteor Shower. (Sept. 1)

* Wed., Sept. 1, 6:00 a.m. EDT / 10:00 UTC - Moon 1.3 degrees north of Open Star Cluster M35. .

* Sept. 2 to 14 (1752) - Anniversary: Adoption, by the British Empire including the American Colonies, of the Gregorian Calendar Reform: the Julian Calendar day of Wednesday, 1752 September 2 O.S. (Old System) was followed by the first day of the Gregorian Calendar, Thursday, 1752 September 14 N.S. (New System). The original Gregorian Calendar Reform occurred when Thursday,1582 October 4 O.S. was followed by Friday, 1582 October 15 N.S.. Gregorian Calendar enacted by the Roman Catholic Church to bring the calendar back into synchronization with the seasons. (Sept. 2 to 14)

* Thur., Sept. 2 (1945) - Anniversary: Victory Over Japan Day / V-J Day (USA) - Day Japan formally surrendered, on Battleship USS Missouri, ending World War II. (Sept. 2)
Celebrated on August 15 in the United Kingdom, for initial announcement of Japan's surrender. (Sept. 2)

* Thur., Sept. 2 (1969) - Anniversary: Public debut of first Automated Teller Machine (ATM) at Chemical Bank in Rockville Center, New York. (Sept. 2)

* Fri., Sept. 3 (1783) - Anniversary of the signing of the Treaty of Paris, which formally ended St. Augustine, Floridathe American Revolutionary War. (Sept. 3)

* Sat., Sept. 4 (1882) - First practical, outdoor electric lighting: Thomas Elva Edison's Direct Current (DC) system in New York City. (Sept. 4)

* Sat., Sept. 4 - Newspaper Carrier Day. (Sept. 4)

* Sat., Sept. 4 - International Vulture Awareness Day - Highlights an ecologically vital group of birds that face a range of threats, including possible extinction for certain species. (First Saturday in September)

* Sept. 5 to 19 - Zodiacal Light dimly visible in northern lattitudes in eastern sky, before morning twilight, for next two weeks. (September, October)

* Sept. 5 to 11 - Suicide Prevention Week. (2nd week of Sept., including Sept. 10: Suicide Prevention Day)

* Sun., Sept. 5, 2:00 a.m. EDT / 6:00 UTC - Venus 1.7 degrees north of star Spica.

* Sept. 6, Sunset to Sept. 8, Sunset - Rosh Hashanah - Jewish New Year: Link 1 *** Link 2.
Days in the Hebrew calendar begin at sunset. Although the Jewish calendar is based on the Lunar Cycle, so that the first day of each month originally began with the first sighting of a New Moon, since the Fourth Century it has been arranged so that Rosh Hashanah never falls on a Sunday, Wednesday, or Friday (although, by the Gregorian Calendar, it may look like the holiday begins on a Sunday, Wednesday, or Friday, by the Hebrew Calendar the next day actually begins at sunset).

* Sept. 6 to 10 - National Payroll Week. (First business week of September, beginning on Labor Day)

* Mon., Sept. 6 - Mercury at aphelion.

* Mon., Sept. 6 - National Read A Book Day. (Sept. 6)

* Mon., Sept. 6 (1966), 7:30 p.m. EDT / 23:30 UTC - Anniversary: World premiere [U.S. premiere on Sept. 8 (1966)] of influential, science-fiction television series, Star Trek, on the CTV television network in Canada. (Sept. 6)

* Mon., Sept. 6 - Labor Day. (Federal Holiday: U.S.A. - First Monday in September)

* Mon., Sept. 6, 8:51 p.m. EDT / Sept. 7, 0:51 UTC - Primary Moon Phase: New Moon - Lunation #1221.

* Wed., Sept. 8 - International Literacy Day. (Sept. 8)

* Wed., Sept. 8 (1565) - Founding of the oldest, continuously-occupied settlement in the continental United States: St. Augustine, Florida. (Sept. 8)

* Wed., Sept. 8 (1966), 8:30 p.m. EDT / Sept. 9 (1966), 0:30 UTC - Anniversary of U.S. premiere [world premiere on Sept. 6 (1966)] of influential, science-fiction television series, Star Trek, on the NBC television network. (Sept. 8)

* Thur., Sept. 9, 10:00 p.m. EDT / Sept. 10, 2:00 UTC - Venus 4 degrees south of the Moon.

* Aug. 6, 7, 8, weekend and September 10, 11, 12, weekend, 30 minutes before sunset - A Swift Night-Out - CITIZEN SCIENCE PROJECT to observe bird roosts of Chimney Swifts and Vaux's Swifts.
More on Citizen Science & Chimey Swifts. (Second Weekend August and September: Friday, Saturday, Sunday)

* Fri., Sept. 10 - Traditional peak in Atlantic Ocean Hurricane Season. (Sept. 10)

* Fri., Sept. 10 - Swap Ideas Day. (Sept. 10)

* Fri., Sept. 10 - Suicide Prevention Day. (Sept. 10)

* Fri., Sept. 10 - National TV Dinner Day. (Sept. 10)

* Fri., Sept. 10, 10:00 p.m. EDT / Sept. 11, 2:00 UTC - Asteroid 2 Pallas at opposition (Pallas visible approx local sunset to local sunrise, weather-permitting)

* Sat., Sept. 11 (2001) - Patriot Day - In commemoration of the 9/11 attacks in New York, Washington, and Shanksville, Pennsylvania (79 miles southeast of Pittsburgh) in 2001. (Sept. 11)
Also 9 / 11 National Day of Service. (Sept. 11)

* Sat., Sept. 11 - World First Aid Day. (Second Saturday in September)

* Sat., Sept. 11, 6:00 a.m. EDT / 10:00 UTC - Moon at perigee: 228,951.1 statute miles / 368,461 kilometers.

* Sept. 12 to 18 - International Book Week. (Third week of September)

* Sept. 12 to 18 - Child Passenger Safety Week (Third week of September).

* Sept. 12 to 18 - National Heroin and Opioid Awareness Week. (Third week of September)

* Sept. 12 to 18 - National Wellness Week. (Third week of September)

* Sept. 12 to 18 - National Assisted Living Week. (Third week of September)

* Sun., Sept. 12 (1962) - U.S. President John F. Kennedy addressed 35,000 people in a football stadium at Rice University in Houston, saying in part:
"We choose to go to the Moon! ...We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard; because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one we intend to win ..." (Sept. 12)

* Sun., Sept. 12 (1958) - Anniversary: Invention of computer Integrated Circuit. (September 12)

* Sun., Sept. 12 - Solar Sidewalk Sun-Day - Annual Sidewalk Astronomers public solar observing event, scheduled each year on the Sunday closest to John Dobson's birthday: Sept. 14. (Sunday closest to Sept. 14)

* Sun., Sept. 12 - Grandparents Day. (First Sunday after Labor Day)

* Mon., Sept. 13 (1926) - Anniversary: Establishment of the NBC Radio Network (designated as the NBC Red Network), the first major national radio network. (Sept. 13)

* Mon., Sept. 13, 4:39 p.m. EDT / 20:39 UTC - Primary Moon Phase: First Quarter.

* Sept. 14, 15, 16 - National Postal Customer Council Week. (Tuesday, Wednesday, Thursday of third week of September)

* Tue., Sept. 14 (1814) - Anniversary: Song, The Star Spangled Banner, which became America's National Anthem in 1931. (Sept.14)

* Tue., Sept. 14, 5:00 a.m. EDT / 9:00 UTC - Neptune at opposition (Neptune visible approx. local sunset to local sunrise, weather-permitting).

* Sept 15, Sunset to Sept. 16, Sunset - Yom Kippur, the Day of Atonement, is the holiest day of the Hebrew faith. It occurs each year on the 10th day of the Jewish month of Tishrei, which is 9 days after the first day of Rosh Hashanah. The Jewish calendar is based on the Lunar Cycle, so that the first day of each month originally began with the first sighting of a New Moon.

* Wed., Sept. 15 - Launch of first all-civilian space mission, Inspiration4 by SpaceX. Crew members billionaire Jared Isaacman, contest winner Sian Proctor, childhood cancer survivor Hayley Arceneaux, and raffle winner Chris Sembroski will ride on this privately-funded mission, which is a fund-raiser for St. Jude Children's Research Hospital in Memphis. The three-day mission will launch in a Crew Dragon capsule atop a Falcon 9 rocket from Launch Complex 39A at NASA's Kennedy Space Center, Cape Canaveral, Florida.

* Wed., Sept. 15 - Happy Engineers Day. (Sept. 15)

* Wed., Sept. 15 - National Tell a Police Officer "Thank You!" Day. (Sept. 15)

* Thur., Sept. 16 - World Ozone Day. (Sept. 16)

in National Make Your Own Ball Day. (Third Thursday of September)

* Thur., Sept. 16, 11:00 p.m. EDT / Sept. 17, 3:00 UTC - Saturn 4 degrees north of the Moon.

* Sept. 17 to 23 - Constitution Week promotes study and education about the U.S. Constitution which was originally adopted by the American Congress of the Confederation on September 17, 1787. (Sept. 17 to 23)

* Fri., Sept. 17 - Constitution Day / Citizenship Day - Commemorates the day of signing of the U.S. Constitution at the Constitutional Convention in 1787. (Sept. 17)

* Fri., Sept. 17 - National POW / MIA Recognition Day. (Third Friday in September)

* Fri., Sept. 17 - Park(ing) Day is an annual worldwide event where artists, designers and citizens transform metered parking spots into temporary public parks. (Third Friday in September)

* Sat., Sept. 18 - Bamboo Day. (Sept. 18)

* Sat., Sept. 18 (1927) - Anniversary: Establishment of the CBS Radio Network, the third national radio network (after the NBC Blue and Red networks), which became prominently known for news broadcasting beginning in World War II. (Sept. 18)

* Sat., Sept. 18 (1947) - Formation of the United States Air Force, as part of the National Security Act of 1947, which also included formation of the Department of Defense (DOD), Central Intelligence Agency (CIA), National Security Council, and the Joint Chiefs of Staff. (Sept. 18)

* Sat., Sept. 18 - National Seat Check Saturday regarding automobile seats for children. (Saturday of Child Passenger Safety Week)

* Sat., Sept. 18 - Software Freedom Day. (Third Saturday in September)

* Sat., Sept. 18 - Thank a Police Officer Day. (Third Saturday of September)

* Sat., Sept. 18, 3:00 a.m. EDT / 7:00 UTC - Jupiter 4 degrees north of the Moon.

* Sept. 19 to 25 - National Adult Education & Family Literacy Week. (Last week of September)

* Sept. 19 to 25 - Sea Otter Awareness Week. (Last full week in September)

* Sept. 19 to 25 - Rail Safety Week. (Last full week of September)

* Sun., Sept. 19 - 'No Text on Board' Pledge Day (TXTNG & DRIVNG...IT CAN WAIT). (Sept. 19)

* Sept. 20 to 26 (1990) - Anniversary: Enactment of the Pollution Prevention Act of 1990 - Pollution Prevention Week. (Third full week of September, beginning on Monday)

* Mon., Sept. 20, Evening - Mid-Autumn Festival / Moon Festival - A popular harvest festival celebrated by Chinese and Vietnamese people, dating back over 3,000 years to Moon worship in China's Shang Dynasty. It is celebrated on the date close to the Harvest Moon in September or October and close to the Autumnal Equinox of the Solar Calendar. (Close to September or October Harvest Moon and Autumnal Equinox)

* Mon., Sept. 20, 7:54 p.m. EDT / 23:54 UTC - Primary Moon Phase: Full Moon - Corn Moon. & Harvest Moon. (The Harvest Moon occurs each year within 15 days of the Autumnal Equinox, on the night of the Full Moon between early September to early October of the Gregorian Calendar)
Also see: Autumnal Equinox.

* Tue., Sept. 21 - World Alzheimer's Day. (Sept. 21)

* Tue., Sept. 21 - International Day of Peace (including International Global Minute of Peace). (Sept. 21)

* Tue., Sept. 21 - World Gratitude Day. (Sept. 21)

* Tue., Sept. 21 (1965) - Anniversary: Commencement by KYW-AM 1060, Philadelphia, of, what is now, the second oldest continuously operating all-news radio station in the United States: Link 1 *** Link 2 (Sept. 21)

* Wed., Sept. 22 - World Car-Free Day. (Sept. 22)

* Wed., Sept. 22 - Hobbit Day - Birthday of the hobbits Bilbo and Frodo Baggins, two fictional characters in J. R. R. Tolkien's popular set of books The Hobbit and The Lord of the Rings. (Sept. 22)

* Wed., Sept. 22 - Falls Prevention Awareness Day. (First day of Fall: ~Sept. 22 or 23)

* Wed., Sept. 22, 3:21 p.m. EDT / 19:21 UTC - Autumnal Equinox; beginning of Season of Autumn in the Northern Hemisphere.
Also see: Harvest Moon.

* Thur., Sept. 23 (1846) - Discovery: Planet Neptune, first planet discovered by mathematical prediction. (Sept. 23)

* Thur., Sept. 23, 9:00 a.m. EDT / 13:00 UTC - Mercury 1.7 degrees south of star Spica.

* March 19 to April 30, September 24 through November 5 - Tsunami Preparedness Weeks. (mid-March through April, mid-September through early November)

* Fri., Sept. 24 - National Punctuation Day. (Sept. 24)

* Fri., Sept. 24, 12:00 Noon EDT / 16:00 UTC - Uranus 1.3 degrees north of the Moon.

* Sept. 25 to Oct. 3 - National Drive Electric Week. (Week of September and / or October, including the whole weekends on both ends of the week)

* Sat., Sept. 25 (1676) - Greenwich Mean Time (GMT), forerunner of today's Coordinated Universal Time (UTC), first established. (Sept. 25)

* Sat., Sept. 25 - Equilux - The actual day with equal hours and minutes of the Sun above the horizon, and equal hours and minutes of the Sun below the horizon. Occurs twice each year, approximately 3-to-4 days before the Vernal Equinox and 3-to-4 days after the Autumnal Equinox. (March 16, September 25)

* Sat., Sept. 25 - National Day of Remembrance for Murder Victims. (Sept. 25)

* Sat., Sept. 25 - National Daughters Day (Sept. 25)

* Sat., Sept. 25 - World School Milk Day. (Sept. 25)

* Sat., Sept. 25 - Better Breakfast Day. (Sept. 25)

* Sat., Sept. 25 - See-Say Day: “If You See Something, Say Something®” Awareness Day. (Sept. 25)

* Sat., Sept. 25 - Museum Day Live! - Free admission to participating museums, with Museum Day ticket from the Smithsonian Magazine web site. (4th Sat. in Sept.)

* Sat., Sept. 25 - National Public Lands Day. (Last Sat. in Sept.)

* Sept. 26 to Oct. 2 - Banned Books Week (BBW) - An annual event celebrating the freedom to read and the importance of the First Amendment. (Last week of September)

* Sun., Sept. 26 (1774) - Birth of pioneer nurseryman and conservationist Johnny Appleseed, who in his early years lived on Grant's Hill (near the present-day site of the 64-story U.S. Steel Building) in Downtown Pittsburgh. (Sept. 26)

* Sun., Sept. 26 - Gold Star Mother's Day. (Last Sun. in Sept.)

* Sun., Sept. 26, 6:00 p.m. EDT / 22:00 UTC - Moon at apogee: 251,431.6 statute miles / 404,640 kilometers.

* Sept. 27 to Oct. 3 - Diaper Need Awareness Week. (Last week of September)

* Sept. 27 to Oct. 6, 8:00 to 10:00 p.m. Prevailing Local Time - CITIZEN SCIENCE - Annual Globe at Night campaign, to raise public awareness of the impact of light pollution by encouraging everyone everywhere to measure local levels of night sky brightness and contribute observations on-line to a world map. (Monthly)

* Mon., Sept. 27 - World Heart Day. (Last Sun. in Sept.)

* Tue., Sept. 28 - National Voter Registration Day. (Fourth Tuesday in September)

* Tue., Sept. 28 - The Right to Know Day. (Sept. 28)

* Tue., Sept. 28 - World Rabies Day, marked on the anniversary of the death of Louis Pasteur. (Sept. 28)

* Tue., Sept. 28 - World Daughters Day (Sept. 28)

* Tue., Sept. 28, 2:00 p.m. EDT / 18:00 UTC - Moon 1.6 degrees north of Open Star Cluster M35.

* Tue., Sept. 28, 9:57 p.m. EDT / Sept. 29, 1:57 UTC - Primary Moon Phase: Last Quarter.

* Wed., Sept. 29 (1915) - First transcontinental radio-telephone demonstration, with U.S. Navy radio stations at Arlington, Virginia, Mare Island in San Francisco, and Honolulu. (Sept. 29)

* May 15 to September 30 - Recreational Boating Season. (May 15 to Sept. 30)

* April 30, Sept. 30 - National PrepareAthon ! Day - Day to emphasize preparation for disasters and emergencies. (April 30, Sept. 30)

* Thur., Sept. 30 - World Maritime Day. (Last Thursday in September)
The original Buhl Planetarium and Institute of Popular Science (a.k.a. Buhl Science Center, Pittsburgh's science and technology museum from 1939 to 1991) displayed the largest Mercator's Projection Map of the World, originally produced by the U.S. Maritime Commission for display at the 1939 World's Fair in New York City.

* Thur., Sept. 30 - National Poetry Day (United Kingdom). (Thur. in late Sept., early Oct.)

* Thur., Sept. 30 - Last day of U.S.A. Federal Fiscal Year. (Sept. 30)

* Thur., Sept. 30 - Last day of Calendar Year Third Quarter. (Sept. 30)

* Thur., Sept. 30 (1452) - Anniversary of the first publication of the Gutenberg Bible, the first major book published using movable type in the Western World. (Sept. 30)

* Thur., Sept. 30 - International Podcast Day™. (September 30)

* Thur., Sept. 30, 10:00 p.m. EDT / 14:00 UTC - Mercury 1.7 degrees south of star Spica.

Astronomical Calendar: 2021 October
Monthly Observances This Month

Space Launches:
NASA Lucy robotic mission to 8 asteroids - Oct. 16
SpaceX Crew-3 mission with 3 NASA astronauts & 1 European astronaut: Oct. 30

Meteor Showers:
Draconid peaks Oct. 7 to 8.
Orionid peaks Oct. 21.

WHY LEAVES
CHANGE COLOR

Autumn Foliage Reports --
Foliage Network Reports
Weather Ch. Viewing Maps
National Forests
New England
PA * WV * OH * MD

Moon Phases:
2021 * Today

Planets, Stars, Sky Events:
Today *** This Week
Solar System
Constellations *** Star Chart

Occultations:
Moon / Bright Stars
Moon / Bright Planet & Asteroid
Moon / Planets & Bright Stars
Major Planets & Moons

View International Space Station (ISS)
Rocket Launches This Month: Link 1 *** Link 2 *** Link 3 *** Link 4

Equinoxes (EQX), Solstices (SOLC), and Cross-Quarter (XQ) Days For This Year.
Chronological Cycles and Eras For This Year.
Dominical Letter: "C" - Used in a Perpetual Calendar. For Non-Leap Year of 2021.

Astronomical Glossary
of Terms Used

Astronomical Calendar
Archives

Other
Astronomical Calendars: Link 1 * Link 2

10,000-Year Calendar

Rise & Set Times

Current Sky Events & Astro Phenomena

News: Astronomy, Space, Science --

Weekly: SpaceWatchtower Blog

Daily: SpaceWatchtower Twitter Feed

History of Pittsburgh's Original
Buhl Planetarium and Institute of Popular Science

Astronomy Links

Science Links


a.m. = Ante-Meridiem (Morning: Midnight to a moment before Noon)

p.m. = Post-Meridiem (Afternoon & Evening: a moment after Noon to a moment before Midnight of the next day)

EST = Eastern Standard Time *** EDT = Eastern Daylight Saving Time *** UTC = Coordinated Universal Time

SPECIAL NOTES:
(1) All astronomical or sky observations are always weather-permitting.
(2) For calendar entries which describe a relationship between two or more celestial objects, unless otherwise noted all relationships between celestial objects are visual relationships as seen from Earth only.


* March 19 to April 30, September 24 through November 5 - Tsunami Preparedness Weeks. (mid-March through April, mid-September through early November)

* Sept. 1 to Nov. 15 - Lights-Out Program to Protect Migratory Birds - Commercial building owners, particularly for tall buildings in large cities, are encouraged to dim their building lights at night to aid migrating birds. (Sept. 1 to Nov. 15)

* Sept. 25 to Oct. 3 - National Drive Electric Week. (Week of September and / or October, including the whole weekends on both ends of the week)

* Sept. 26 to Oct. 2 - Banned Books Week (BBW) - An annual event celebrating the freedom to read and the importance of the First Amendment. (Last week of September)

* Sept. 27 to Oct. 3 - Diaper Need Awareness Week. (Last week of September)

* Sept. 27 to Oct. 6, 8:00 to 10:00 p.m. Prevailing Local Time - CITIZEN SCIENCE - Annual Globe at Night campaign, to raise public awareness of the impact of light pollution by encouraging everyone everywhere to measure local levels of night sky brightness and contribute observations on-line to a world map. (Monthly)

* October through December - The Rut, White-Tailed Deer Mating Season - Vehicle drivers should be on the look-out for deer running across streets and highways. (Oct. through Dec.)

* Fri., Oct. 1 (1847), 10:50 p.m. (Massachusetts time) - America's first professional woman astronomer, Maria Mitchell, discovered Miss Mitchell's Comet. (Oct. 1)

* Fri., Oct. 1 (1958) - Anniversary: Official establishment of NASA, the National Aeronautics and Space Administration, as America's civilian space agency, from the predecessor, the National Advisory Committee for Aeronautics (NACA) which had been formed in 1915. (Oct. 1)
NASA: Link 1 *** Link 2.

* Fri., Oct. 1 - Median date for first Fall frost for locations in the Allegheny Mountains of Pennsylvania, West Virginia, and Maryland, as well as northern counties in Pennsylvania. (Oct. 1)

* Fri., Oct. 1 - College Radio Day. (Oct. 1)

* Fri., Oct. 1 - First day of U.S.A. Federal Fiscal Year. (Oct. 1)

* Fri., Oct. 1 - First day of Calendar Year Fourth Quarter. (Oct. 1)

* Fri., Oct. 1 - Manufacturing Day℠. (Friday in first week of October)

* Sat., Oct. 2 (1925) - First test of a working Television receiver. (Oct. 2)

* Sat., Oct. 2 - Cassette Store Day. (First Saturday in October)

* Sat., Oct 2 - American Graduate Day. (First Saturday in October)

* Oct. 3 to 11 - Biology Week. (First full week in October, including both full weekends on both sides of the week)

* Oct. 3 to 9 - National Employ the Physically Handicapped Week. (First week of October)

* Oct. 3 to 9 - Mental Illness Awareness Week (MIAW) / Mental Health Awareness Week. (First Full Week of October)

* Oct. 3 to 9 - Newspaper Week. (First full week of Oct., Sun. to Sat.)

* Oct. 3 to 9 - Fire Prevention Week. (Week, from Sunday to Saturday, which includes October 9)

* Oct. 3 to 9 - National Customer Service Week. (First week of October)

* Sun., Oct. 3 - Venus at aphelion.

* Sun., Oct. 3 - Ostomy Awareness Day. (Oct. 3)

* May 10 to 16 / Oct. 4 to 10 - International Astronomy Week. (Begins on the Monday preceding the Saturday designated as International Astronomy Day). (April or May / September or October)

* Oct. 4 to 10 - World Space Week. (Oct. 4 to 10)

* Oct. 4 to 15 (1582) - Anniversary of original Gregorian Calendar Reform: the Julian Calendar day Thursday,1582 October 4 O.S. (Old System) was followed by the first day of the Gregorian Calendar, Friday, 1582 October 15 N.S. (New System). The British Empire, including the American Colonies, adopted the Gregorian Calendar when Wednesday, 1752 September 2 O.S. was followed by Thursday, 1752 September 14. N.S. Gregorian Calendar enacted by Roman Catholic Church to bring the calendar back into synchronization with the seasons. (Oct. 4 to 15)

* Oct. 4 to 10 - National Metric Week. [Week containing Oct. 10 (10-10)]

* Mon., Oct. 4 (1957) - Anniversary: Beginning of the Space Age with the first successful launch and orbit of an artificial satellite, Sputnik 1, by the Union of Soviet Socialist Republics (the country today known by their traditional name, Russia). (Oct. 4)

* Mon., Oct. 4 - U.S. Supreme Court begins new term. (First Monday in October)

* Mon., Oct. 4, Before Morning Twilight - Zodiacal Light dimly visible in northern latitudes in eastern sky, before morning twilight, for next two weeks. (September, October)

* Mon., Oct. 4, 2:53 p.m. EDT / 18:53 UTC - Double-shadow (shadows of 2 of 4 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise, weather-permitting.

* Tue., Oct. 5 - World Teachers' Day. (Oct. 5)

* Tue., Oct. 5 - World Architecture Day. (First Monday of October)

* Tue., Oct. 5 (1962) - Global James Bond Day. (Oct. 5: Anniversary of 1962 release of motion picture, "Dr. No")

* Tue., Oct. 5 - News Engagement Day. (First Tuesday in October)

* Wed., Oct. 6 - International Walk-to-School Day. (First Wednesday in October)

* Wed., Oct. 6, 7:05 a.m. EDT / 11:05 UTC - Primary Moon Phase: New Moon - Lunation #1222

* Thur., Oct. 7 - National Depression Screening Day® (NDSD) . (Thursday of Mental Illness Awareness Week)

* Fri., Oct. 8 - World Egg Day. (Second Friday in October)
Also see: Embryology "Chick Hatching" Exhibit at the original Buhl Planetarium and Institute of Popular Science (a.k.a. Buhl Science Center - Pittsburgh's science and technology museum from 1939 to 1991).

* Fri., Oct. 8, 12:00 Midnight EDT / 4:00 UTC - Mars in conjunction with the Sun (Mars not visible, even with a telescope)

* Fri., Oct. 8, 1:00 p.m. EDT / 17:00 UTC - Moon at perigee: 225,797.6 statute miles / 363,386 kilometers.

* Fri., Oct. 8 (Best viewing: Evening after sunset, weather-permitting - short-lived meteor shower) - Peak of October Draconid Meteor Shower. (Oct. 7 to 8)

* Saturday - May 15 / Oct. 9 - International Astronomy Day. [Saturday closest to First Quarter Primary Phase of the Moon, in April or May (Spring - Saturday of International Astronomy Week) and in September or October (Autumn)]: Link 1 *** Link 2 *** Link 3 *** Link 4

* Oct. 9 to 17 - Week of Non-Violence. (Second full week of October, including Saturday and Sunday of both weekends on both sides of the week)

* Sat., Oct. 9 - Leif Erikson Day honors the Norse explorer who brought the first Europeans known to have set foot in North America. (Oct. 9)

* Sat., Oct. 9 - Fire Prevention Day. (Oct. 9)

* Sat., Oct. 9 - Newspaper Carrier Day. (Saturday of Newspaper Week, which is first full week of Oct., Sun. to Sat.)

* Sat., Oct. 9 - Indie Author Day. (Second Saturday in October)

* Sat., Oct. 9, 12:00 Noon EDT / 16:00 UTC - Mercury in inferior conjunction with the Sun (Mercury not visible, even with at telescope).

* Sat., Oct. 9, 3:00 p.m. EDT / 19:00 UTC - Venus 3 degrees south of the Moon.

* Oct. 10 to 16 - Ada Lovelace Week - Celebrates the achievements, in general, of women in STEM careers (Science, Technology, Engineering, and Mathematics), and in particular, in memory of Ada Lovelace, the first computer programmer. (Week including the second Tuesday of October)

* Oct. 10 to 16 - Earth Science Week. (Second full week of October)

* Oct.10 to 16 - Teen Read Week. (Week including Columbus Day)

* Sun., Oct. 10 - National Metric Day. (10-10)

* Sun., Oct. 10 - World Mental Health Day. (Oct. 10)

* Sun., Oct. 10 - Clergy Appreciation National Day of Honoring. (Second Sunday in October)

* Mon., Oct. 11 - International Day of the Girl Child. (Oct. 11)

* Mon., Oct. 11 - Chistopher Columbus Day Observed: Federal Holiday in U.S.A. (Second Monday in October).
* Mon., Oct. 11 - Indigenous Peoples' Day - Observed by some communities as an alternative to Christopher Columbus Day. (Second Monday in October)

* Mon., Oct. 11 - Thanksgiving Day (Canadian): Federal Holiday in Canada. Canadian Thanksgiving Day is about a month earlier than American Thanksgiving Day, due to the earlier harvest in the far northern latitudes. (Second Monday in October)

* Tue., Oct. 12 - Ada Lovelace Day - Celebrates the achievements, in general, of women in STEM careers (Science, Technology, Engineering, and Mathematics), and in particular, in memory of Ada Lovelace, the first computer programmer. (Second Tuesday of October)

* Tue., Oct. 12 - Anniversary: Chistopher Columbus Day. (Oct. 12)

* Tue., Oct. 12, 11:25 p.m. EDT / Oct. 13, 3:25 UTC - Primary Moon Phase: First Quarter.

* May 11 to 16 - POSTPONED TO Oct. 13 to 17 - National Police Week. [Week including National Peace Officers' Memorial Day (May 15)]

* Wed., Oct. 13 (1775) - Anniversary: Establishment of the U.S. Navy, originally the Continental Navy during the American Revolutionary War. (Oct. 13)

* Thur., Oct. 14 (1947) - Chuck Yeager officially broke the sound barrier. (Oct. 14)
In 2012, At Age 89, Chuck Yeager AGAIN Breaks Sound Barrier.

* Thur., Oct. 14 - World Standards Day. (Oct. 14)

* Thur., Oct. 14 - National Fossil Day. (Oct. 14)

* Thur., Oct. 14, 3:00 a.m. EDT / 7:00 UTC - Saturn 4 degrees north of the Moon.

* Fri., Oct. 15 - Equilux when considering Civil Twilight (Dawn before sunrise and Dusk after sunset) - When considering Civil Twilight, the day when daylight and darkness, both, have the same length of hours and minutes. Occurs twice each year, approximately 23 days before the Vernal Equinox and 23 days after the Autumnal Equinox. (Feb. 25 to 26, Oct. 15)

* Fri., Oct. 15 (1582) - Roman Catholic Church instituted the Gregorian Calendar Reform. As part of the Reform, 10 days in October (October 5 through 14) were deleted for the year A.D. 1582, due to the 13 centuries of accumulated error causing a calendar drift of holidays (particularly Easter). In 1582, the date of October 4 (Julian Calendar) was followed the next day by October 15 (Gregorian Calendar). Great Britain and the American Colonies did not adopt the Gregorian Calendar Reform until September of 1752. (Oct. 15)

* Fri., Oct. 15 - Global Handwashing Day. (Oct. 15)

* Fri., Oct. 15 (1975) - Anniversary: Commencement by KQV-AM 1410, Pittsburgh (one of the nation's oldest radio stations, having started on 1919 November 19) of all-news radio broadcasting, until the radio station suspended broadcasting on 2017 December 31.: Link 1 *** Link 2 (Oct. 15)

* Fri., Oct. 15 - National Boss Day. (Oct. 16, unless date falls on weekend, then closest working day to Oct. 16)

* Fri., Oct. 15, 6:00 a.m. EDT / 10:00 UTC - Jupiter 4 degrees north of the Moon.

* Sat., Oct. 16 - National Dictionary Day. (Oct. 16)

* Sat., Oct. 16 - World Food Day / Food Engineer Day. (Oct. 16)

* Sat., Oct. 16 - Sweetest Day. (Third Saturday in October)

* Sat., Oct. 16 (1957, 10:05 a.m. MST / 12:05 p.m. EST / 17:05 UTC) - U.S. Air Force successfully launches two man-made pellets beyond Earth's gravity into Solar Orbit, from an Aerobee rocket at the Hollornan Air Force Base in Alarnogordo, New Mexico.

* Sat., Oct. 16, 5:34 a.m. EDT / 9:34 UTC - Scheduled launch of NASA's Lucy uncrewed mission to 8 of Jupiter’s Trojan asteroids, within 12 years.

* Sat., Oct. 16, 10:00 a.m. EDT / 14:00 UTC - Venus 1.5 degrees north of star Antares.

* Sat., Oct. 16, Evening - International Observe the Moon Night (InOMN). (Saturday evening at end of Sept. or beginning of Oct.)
More info.

* Oct. 17 to 23 - National Chemistry Week (NCW). (3rd or 4th full week of October)

* Oct. 17 to 23 - National Friends of Libraries Week. (3rd or 4th full week of October)

* Oct. 17 to 23 - National School Bus Safety Week. (Third Week in October)

* Oct. 17 to 23 - National Teen Driver Safety Week. (Third full week of October)

* Oct. 17 to 23 - Male Breast Cancer Awareness Week. (Third full week of October)

* Oct. 17 to 23 - CHARACTER COUNTS! Week. (Third full week of October)

* Oct. 17 to 23 - National Retirement Security Week. (Third week of October)

* Sun., Oct. 17 (1919) - Anniversary: Amateur radio station 8XK in Wilkinsburg, Pennsylvania, indirect predecessor to KDKA-AM Pittsburgh (world's first commercial radio station in 1920), started broadcasting in Pittsburgh region, after World War I restrictions on amateur radio were lifted by the Federal Government. (Oct. 17)

* Oct. 18 to 24 - National Estate Planning Awareness Week. (Sept. or Oct.)

* Mon., Oct. 18 (1767) - Anniversary: Completion of the Mason-Dixon Line Survey, America's most famous boundary line [separating Pennsylvania from Maryland & Virginia (now West Virginia)], produced with the assistance of Astronomy. The Survey ended, prematurely, about 70 miles south of Pittsburgh, when the Native American guides of Astronomers Charles Mason and Jeremiah Dixon refused to enter their Indian enemy's territory. Philadelphia clock-maker and Astronomer David Rittenhouse, with Surveyor Andrew Ellicott, completed surveying the last 23 miles (to the southwest corner of Pennsylvania) in 1784. (Oct. 18}

* Mon., Oct. 18 - Feast Day of Saint Luke / brief period around October 18 known as Saint Luke's Little Summer, when there is often a short time of calm, dry weather, with mild temperatures. (Oct. 18)
Also see: Stage performance of "Saint Luke," during the historic Star of Bethlehem planetarium drama, at the time of the Christmas holidays at Pittsburgh's original Buhl Planetarium and Institute of Popular Science.

* Mon., Oct. 18 - Mercury at perihelion.

* Tue., Oct. 19 - Great ShakeOut Earthquake Drills. (Oct. 19)

* Tue., Oct. 19 - National New Friends Day. (Oct. 19)

* Tue., Oct. 19, 2:12 a.m. EDT / 6:12 UTC - Double-shadow (shadows of 2 of 4 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise, weather-permitting.

* Wed., Oct. 20 - Average end of the Growing Season for the Pittsburgh Quad-State Region (Western Pennsylvania, Eastern Ohio, Northern West Virginia, and Western Maryland, except at the higher elevations in the Allegheny Mountains). (Oct. 20)

* Wed., Oct. 20 - World Osteoporosis Day. (Oct. 20)

* Wed., Oct. 20 - Global Ethics Day announced by the Carnegie Council for Ethics in International Affairs. (Third Wednesday in October)

* 2025 Oct. 20 - World Statistics Day. (Oct. 20, every five years starting in 2010)

* Wed., Oct. 20, 10:56 a.m. EDT / 14:56 UTC - Primary Moon Phase: Full Moon - Hunter's Moon

* Thur., Oct. 21 - Get Smart About Credit Day. (Third Thursday in October)

* Thur., Oct. 21 - National Reptile Awareness Day. (Oct. 21)

* Thur., Oct. 21, 8:00 a.m. EDT / 12:00 UTC (Best viewing: Midnight to Dawn, weather-permitting) - Peak of Orionid Meteor Shower - Remnants from Halley's Comet. (Oct. 21)
"Two-Timers," visitors to Pittsburgh's original Buhl Planetarium who saw Halley's Comet in both 1910 and in 1985 to 1986 (in 1985 to 1986 with a Buhl Planetarium telescope, including the historic 10-Inch Siderostat-Type Refractor Telescope).

* Thur., Oct. 21, 6:00 p.m. EDT / 22:00 UTC Uranus 1.3 degrees north of the Moon.

* Oct. 22 to 26 - Solar Week. (Mid-to-Late March; Mid-to-Late October: weekdays)

* Fri., Oct. 22 - National Make A Dog’s Day with adoption from a local animal shelter. (Oct. 22)

* Sat., Oct. 23 (1939) - Anniversary: Press Preview, prior to Tuesday Evening, 1939 October 24 dedication of Pittsburgh's original Buhl Planetarium and Institute of Popular Science. (Oct. 23)
The original Buhl Planetarium (a.k.a. Buhl Science Center - Pittsburgh's science and technology museum from 1939 to 1991) included two historic astronomical instruments:
1) Zeiss II Planetarium Projector, the oldest operable major planetarium projector in the world ! (presently on display as a non-working exhibit).
2) Rather unique 10-inch Siderostat-type Refractor Telescope, which marked its 75th anniversary on 2016 November 19.

* Sat., Oct. 23 (2001) - iPOD Day. (Oct. 23)

* Sat., Oct. 23 - Day of San Juan - Swallows leave Mission San Juan Capistano, California. (Oct. 23)

* Sat., Oct. 23 - National Forgiveness Day. (Fourth Saturday of October)

* Sat., Oct. 23, 10:00 a.m. to 2:00 p.m. Prevailing Local Time - National Prescription Drug Take-Back Days sponsored by the U.S. Drug Enforcement Administration. (4th Saturday in September or October, 10:00 a.m. to 2:00 p.m. Prevailing Local Time)

* Sat., Oct. 23, 6:02 a.m. to 6:02 p.m EDT / 10:02 to 22:02 UTC - Mole Day, unofficial holiday celebrated among chemists, chemistry students, and chemistry enthusiasts, between 6:02 a.m. and 6:02 p.m., making the date 6:02 10/23 in the American style of writing dates. The time and date are derived from Avogadro's number, which is approximately 6.02 × 1023, defining the number of particles (atoms or molecules) in one mole (mol) of substance, one of the seven base SI units. (Oct. 23)

* Oct. 24 to 31 - National Bat Week. (Week that includes Halloween Day: Oct. 24 to 31)

* Oct. 24 to 30 - Open Access Week. (Last full week of October)

* Oct. 24 to 30 - National Legal Pro-Bono Celebration Week. (Last week of October)

* Sun., Oct. 24 - World Polio Day (Oct. 24)

* Sun., Oct. 24 (1945) - Anniversary: Founding of the United Nations. (Oct. 24)

* Sun., Oct. 24 (1851) - Astronomer William Lassell discovered Uranus moons Ariel and Umbriel. (Oct. 24)

* Sun., Oct. 24 - Mother-in-Law Day. (Fourth Sunday in October)

* Sun., Oct. 24, 2:00 a.m. Prevailing Local Time (Daylight Saving Time) - DAYLIGHT SAVING TIME CONTINUES - Change in Federal law, thus that return to Standard Time occurs 2:00 a.m. Daylight Saving Time (which becomes 1:00 a.m. Standard Time) on the first Sunday in November (previously, last Sunday in October, 2:00 a.m. Prevailing Local Time).
(Last Sunday in October)
Also see:
Some States to Abandon Daylight Saving Time ?
Science of Daylight Saving Time.

* Sun., Oct. 24, 11:00 a.m. EDT / 15:00 UTC Moon at apogee: 252,037.5 statute miles / 405,615 kilometers.

* Sat., Oct. 24 (1939), 8:30 p.m. EST / Oct. 25, 1:30 UTC (Daylight Saving Time not observed in 1939) - Anniversary: Dedication of Pittsburgh's original Buhl Planetarium and Institute of Popular Science. (Oct. 24)
The original Buhl Planetarium (a.k.a. Buhl Science Center - Pittsburgh's science and technology museum from 1939 to 1991) included two historic astronomical instruments:
1) Zeiss II Planetarium Projector, the oldest operable major planetarium projector in the world ! (presently on display as a non-working exhibit).
2) Rather unique 10-inch Siderostat-type Refractor Telescope, which marked its 75th anniversary on 2016 November 19.

* Mon., Oct. 25 (1939), 10:00 a.m. EST / 15:00 UTC (Daylight Saving Time not observed in 1939) - Anniversary: Public Opening of Pittsburgh's original Buhl Planetarium and Institute of Popular Science. (Oct. 25)
The original Buhl Planetarium (a.k.a. Buhl Science Center - Pittsburgh's science and technology museum from 1939 to 1991) included two historic astronomical instruments:
1) Zeiss II Planetarium Projector, the oldest operable major planetarium projector in the world ! (presently on display as a non-working exhibit).
2) Rather unique 10-inch Siderostat-type Refractor Telescope, which marked its 75th anniversary on 2016 November 19.

* Mon., Oct. 25, 10:00 p.m. EDT / Oct. 26, 2:00 UTC - Moon 1.7 degrees north of open star cluster M35.

* Tue., Oct. 26 - National Pumpkin Day. (Oct. 26)

* Tue., Oct. 26, 4:08 a.m. EDT / 8:08 UTC - Double-shadow (shadows of 2 of 4 Galilean Moons) transit on Jupiter; visible, with difficulty, through telescope after sunset or before sunrise, weather-permitting.

* Wed., Oct. 27 (1858) - Navy Day, the date of the birthday of U.S. President Theodore Roosevelt, who served as Assistant Secretary of the Navy (1897 to 1898), wrote the book, The Naval War of 1812 (1882), and as President built-up the U.S. Navy as a world-class fighting fleet. (Oct. 27 is recognized as Navy Day in the U.S. Flag Code, for the display of the U.S. flag.). (Oct. 27)

* Wed., Oct. 27 - World Day for Audiovisual Heritage. (Oct. 27)

* Wed., Oct. 27 - Occupational Therapy Day. (Oct. 27)

* Wed., Oct. 27 - National Potato Day. (Oct. 27)

* Oct. 28 & 29 (1929) - Black Monday (Oct. 28) & Black Tuesday (Oct. 29) Wall Street Stock Market Crash of 1929. (Oct. 28 & 29)

* Thur., Oct. 28, 4:05 p.m. EDT / 20:05 UTC - Primary Moon Phase: Last Quarter.

* Fri., Oct. 29 (1969) - Anniversary: Connection of the first two nodes of the ARPANET, which led to the formation of the Internet. (Oct. 29)

* Fri., Oct. 29 - National Cat Day. (Oct. 29)

* Sat., Oct. 30 - Launch of SpaceX Crew-3 mission to International Space Station (ISS), in a Crew Dragon capsule on a Falcon 9 rocket from Cape Canaveral, Florida, with NASA astronauts Raja Chari, Tom Marshburn, and Kayla Barron as well as ESA (European Space Agency) astronaut Matthias Maurer.

* Sat., Oct. 30 (1938), 8:00 p.m. EST / Oct. 31, 1:00 UTC (Daylight Saving Time not observed in 1938) - Anniversary: CBS Radio Network broadcast of Orson Welles' radio adaptation of the H.G. Wells science-fiction novel, The War of the Worlds, which caused a panic among some American listeners who thought the Earth was actually being invaded by beings from the Planet Mars. (Oct. 30)

* Oct. 31 / Nov. 1 / Nov. 2 - Traditional Astronomical Cross-Quarter Day Samhain or "All-Hallowsmas", better known as Halloween (Oct. 31 - "All Hallows Eve"), All-Saints Day (Nov. 1), All-Souls Day (Nov. 2) (fourth and last traditional cross-quarter day of year). Also, Oct. 31 - Anniversary (1517): Protestant Reformation Day.

What is a "Cross-Quarter Day" ?
What is the Astronomical significance of
Halloween, All-Saints Day, and All-Souls Day?
Link 1 *** Link 2 *** Link 3 *** Link 4
Actual Cross-Quarter Day.

* Sun., Oct. 31 - Dark Matter Day. (Oct. 31)

* Mon., Nov. 1, 2:00 a.m. Prevailing Local Time (Daylight Saving Time) - DAYLIGHT SAVING TIME ENDS - Change in Federal law thus that return to Standard Time occurs 2:00 a.m. Daylight Saving Time (which becomes 1:00 a.m. Standard Time). (First Sunday in November, 2:00 a.m. Prevailing Local Time)
Some States to Abandon Daylight Saving Time ?
Science of Daylight Saving Time.

* Tue., Nov. 2 - General Election Day (First Tuesday after the first Monday in November):
Local and state elections. (First Tuesday after the first Monday in November)

* Sat., Nov. 6, 11:50 p.m. EST / Nov. 7, 3:50 UTC - Actual Astronomical Cross-Quarter Day (fourth and last actual cross-quarter day of the year: ~Nov. 6-7).
Traditional Cross-Quarter Day.

Return to History of The Buhl Planetarium and Institute of Popular Science, Pittsburgh

Astronomical Calendar - A.D. 2021

Authored By Glenn A. Walsh *** Sponsored By Friends of the Zeiss
Electronic Mail: < astrocalendar@planetarium.cc > *** Internet Web Cover Page: < http://www.planetarium.cc >
This Internet Web Page: < https://buhlplanetarium4.tripod.com/astrocalendar/2021.html >
SpaceWatchtower Blog
2021 January

Internet Web Site Master Index for the History of
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Other Internet Web Sites of Interest

History of The Buhl Planetarium and Institute of Popular Science, Pittsburgh

History of Adler Planetarium and Astronomy Museum, Chicago

Astronomer, Educator, and Telescope Maker John A. Brashear

History of Andrew Carnegie and Carnegie Libraries

Historic Duquesne Incline cable-car railway, Pittsburgh

Disclaimer Statement: This Internet Web Site is not affiliated with the Andrew Carnegie Free Library,
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