Wednesday, December 15, 2010

2010 Total Lunar Eclipse Tuesday, Dec. 21, Favors North America


Summary: As the year’s second eclipse of the moon, the 2010 total lunar eclipse Tuesday, Dec. 21, favors North America.


visibility of the Dec. 21, 2010, lunar eclipse: Fred Espenak/NASA Goddard Space Flight Center (GSFC), Public Domain, via Wikimedia Commons

As the year’s second eclipse of the moon, the 2010 total lunar eclipse Tuesday, Dec. 21, favors North America, northwestern South America (Colombia, Ecuador, Peru, Venezuela), Greenland, Iceland, northern Scandinavia and northern Russia with entire visibility.
NASA’s Eclipse Web Site details the astronomical event as beginning at 5:29:17 Universal Time (12:29:17 a.m. Eastern Standard Time) with a penumbral eclipse, with the lunar passage through the penumbra, the faint, outer cone of Earth’s shadow. Astronomers designate the penumbral start as P1.
At 6:32:37 UT (1:32:37 a.m. EST), the event’s partial eclipse begins. Partiality signals the movement of only a portion of the visible lunar surface into the umbra, the darkest, innermost segment of Earth’s shadow. U1 designates the start of partiality.
At 7:40:47 UT (2:40:47 a.m. EST), the total eclipse begins. Totality indicates the moon’s complete movement into Earth’s umbra. U2 is the astronomical designation for the start of totality.
Greatest eclipse takes place at 8:16:57 UT (3:16:57 a.m. EST). Greatest eclipse references the instant of the moon's closest passage to the axis of Earth's shadow.
The total eclipse ends at 8:53:08 UT (3:53:08 a.m. EST). U3 designates the end of totality.
The partial eclipse ends at 10:01:20 UT (5:01:20 a.m. EST). U4 designates the end of partiality.
At 11:04:31 UT (6:04:31 a.m. EST) the penumbral eclipse ends. P4 designates the penumbral end.
The penumbral eclipse frames the December 2010 lunar event. The penumbral eclipse, occurring from 5:29:17 UT (12:29:17 a.m. EST) to 11:04:31 UT (6:04:31 a.m. EST), accounts for 5 hours 35 minutes 14 seconds.
Like a set of Russian nesting dolls, the penumbral eclipse encompasses a partial eclipse and a total eclipse within its time span. Partiality, spanning 6:32:37 UT (1:32:37 a.m. EST) to 10:01:20 UT (5:01:20 a.m. EST), has a duration of 3 hours 28 minutes 43 seconds. Totality, which runs from 7:40:47 UT (2:40:47 a.m. EST) to 8:53:08 UT (3:53:08 a.m. EST), has a duration of 1 hour 12 minutes 21 seconds.
The 2010 total lunar eclipse ends a drought of almost 2 years 10 months of no total lunar eclipses. The most recent predecessor of the Dec. 21, 2010, total lunar eclipse took place early in 2008.
Time And Date’s web site frames the 2008 total lunar eclipse with a penumbral eclipse that started at 00:36:36 UT, Thursday, Feb. 21 (7:36:36 p.m. EST, Wednesday, Feb. 20) and ended Feb. 21 at 6:15:36 UT (1:15:36 a.m. EST). Totality occurred between 3:01:10 UT, Feb. 21 (10:01:10 p.m. EST, Feb. 20) and 3:50:54 UT, Feb. 21 (10:50:54 p.m. EST, Feb. 20).
The 2010 total lunar eclipse also shares its date with the Northern Hemisphere’s winter solstice, which is known as the summer solstice in the Southern Hemisphere. The second of the two annual solstices takes place Dec. 21, 2010, at 23:38 UT (6:38 p.m. EST). A span of about 12 hours 34 minutes separates the end of the day’s lunar eclipse and the solstice’s official start.
The 2010 total lunar eclipse Tuesday, Dec. 21, happens as the second of the year’s two lunar eclipses. The year’s first lunar eclipse occurred Saturday, June 26, as a partial lunar eclipse.
December 2010's total lunar eclipse belongs to Saros 125. The Saros cycle for lunar and solar eclipses encompasses a period of 18 years 11 days 8 hours (approximately 6,585.3 days). The Saros cycle organizes eclipses into families, known as series.
The takeaway for the 2010 total lunar eclipse Tuesday, Dec. 21, is that the event favors North America as the only continent with entire visibility, coincides with the year’s December solstice and ends a 2 year 9-plus month drought of total lunar eclipses.

moon’s approximate appearance during passage through Earth’s shadows, with red glowing light inside the umbral shadow: SockPuppetForTomruen at English Wikipedia, Public Domain, via Wikimedia Commons

Acknowledgment
My special thanks to:
Talented artists and photographers/concerned organizations who make their fine images available on the Internet;
Virginia Polytechnic Institute and State University for superior on-campus and on-line resources.
Image credits:
visibility of the Dec. 21, 2010, lunar eclipse: Fred Espenak/NASA Goddard Space Flight Center (GSFC), Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Visibility_Lunar_Eclipse_2010-12-21.png
moon’s approximate appearance during passage through Earth’s shadows, with red glowing light inside the umbral shadow: SockPuppetForTomruen at English Wikipedia, Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Lunar_eclipse_chart_close-2010Dec21_animation.gif

For further information:
“February 20 / February 21, 2008 -- Total Lunar Eclipse.” Time And Date > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/lunar/2008-february-21
“December 20 / December 21, 2010 -- Total Lunar Eclipse.” Time And Date > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/lunar/2010-december-21
“Earth’s Seasons: Equinoxes, Solstices, Perihelion, and Aphelion.” U.S. Naval Observatory Astronomical Applications Department > Data Services.
Available @ http://aa.usno.navy.mil/data/docs/EarthSeasons.php
Espenak, Fred. “2010 Dec 21: Total Lunar Eclipse.” NASA Eclipse Web Site > Eclipses During 2010.
Available @ https://eclipse.gsfc.nasa.gov/OH/OH2010.html
Espenak, Fred; Jean Meeus. "Saros Series 125." NASA Eclipse Web Site > Lunar Eclipses > Catalog of Lunar Eclipse Saros Series.
Available @ https://eclipse.gsfc.nasa.gov/LEsaros/LEsaros125.html
“When Is the Longest/Shortest Day? Summer/Winter Solstices and Spring/Autumn Equinoxes.” Greenwich Mean Time.
Available @ https://greenwichmeantime.com/longest-day/equinox-solstice-2010-2019/

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