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.

Return to History of The Buhl Planetarium and Institute of Popular Science, Pittsburgh

Astronomical Calendar - A.D. 2021

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Electronic Mail: < astrocalendar@planetarium.cc > *** Internet Web Cover Page: < http://www.planetarium.cc >
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2021 January

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History of The Buhl Planetarium and Institute of Popular Science, Pittsburgh

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History of Andrew Carnegie and Carnegie Libraries

Historic Duquesne Incline cable-car railway, Pittsburgh

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