First of Three 2013 Lunar Eclipses Happens April 25 as Partial Eclipse

Summary: The first of three 2013 lunar eclipses happens April 25 as a partial eclipse that disfavors North America and favors Africa, Asia and Australia.

Earth visibility chart and eclipse data for partial lunar eclipse of Thursday, April 25, 2013: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak, NASA GSFC Emeritus," via NASA Eclipse Web Site

The first of three 2013 lunar eclipses happens April 25 as a partial eclipse disfavoring North America as a no-visibility continent and favoring the Indian Ocean, most of Africa and much of central and western Asia with all eclipse visibility.

On the NASA Eclipse Web Site, retired astrophysicist Fred Espenak, known as “Mr. Eclipse,” identifies areas of all eclipse visibility. Eastern Africa, central Asia, western Australia and eastern Europe offer visibility of the entire ecliptic event.

Northwestern South America joins North America in no-visibility of the April 2013 partial eclipse. Espenak notes that eastern parts of South America experience only part of the ecliptic event because the start of the eclipse precedes moonrise there.

The Indian Ocean is the only one of Earth’s three major oceans to enjoy all eclipse visibility. The Southern Ocean and the continent that it surrounds, Antarctica, also fall within the area of all eclipse visibility.

The first of three 2013 lunar eclipses begins with the lunar surface’s first contact with Earth’s lighter, outer shadow, known as penumbra. The start of the penumbral eclipse, designated as P1, happens Thursday, April 25, at 18:03:38 Universal Time (2:03 p.m. Eastern Daylight Time).

The partial eclipse starts at 19:54:08 UT (3:54 p.m. EDT) with first contact of the lunar surface with Earth’s umbra. U1 designates the instant of first entrance into the darkest, innermost part of Earth’s shadow.

During the partial eclipse, Earth’s umbra only covers a portion of the visible lunar surface. The partial coverage that distinguishes a partial lunar eclipse differs from the umbra’s total coverage of the lunar surface that characterizes a total lunar eclipse.

Greatest eclipse happens at 20:07:30 UT (4:07 p.m. EDT). Greatest eclipse references the instant of the moon’s closest passage to the axis of Earth’s shadow.

The partial eclipse ends at 20:21:02 UT (4:21 p.m. EDT). U4 designates the instant of the event’s last umbral contact.

The penumbral eclipse ends at 22:11:26 UT (6:11 p.m. EDT). P4 is the designator for the instant of last penumbral contact. The end of the penumbral eclipse also signifies the end of the April 2013 lunar eclipse.

The April 2013 event’s penumbral eclipse has a total duration of 4 hours 7 minutes 48 seconds. Within the total time frame, the event’s partial eclipse lasts for 26 minutes 54 seconds.

The April 2013 partial lunar eclipse is sandwiched between penumbral lunar eclipses. A penumbral eclipse on Wednesday, Nov. 28, closed 2012’s lineup of two lunar eclipses. The April 2013 event opens the year as the only partial lunar eclipse among 2013’s three lunar eclipses. The two consecutive penumbral lunar eclipses appearing in the wake of the April partial lunar eclipse take place Saturday, May 25, and Friday, Oct. 18.

After the April 2013 ecliptic event, partial lunar eclipses disappear from eclipse lineups for four and one-fourth years. The next appearance of a partial lunar eclipse occurs Monday, Aug. 7, 2017.

The April 2013 partial lunar eclipse belongs to Saros Series 112. The Saros cycle associates eclipses into families, known as series. A Saros cycle covers approximately 6,585.3 days (18 years 11 days 8 hours).

The first of three 2013 lunar eclipses happens April 25 as a partial eclipse, favors the Indian Ocean with complete visibility and, in the event’s aftermath, marks an absence of partial lunar eclipses from eclipse lineups for four and one-fourth years.

graphic of "orientation of the earth as viewed from the center of the moon during greatest eclipse" for partial lunar Eclipse of Thursday, April 25, 2013: 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.

Image credits:

Earth visibility chart and eclipse data for partial lunar eclipse of Thursday, April 25, 2013: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak, NASA GSFC Emeritus," via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/OH/OHfigures/OH2013-Fig01.pdf

graphic of "orientation of the earth as viewed from the center of the moon during greatest eclipse" for partial lunar Eclipse of Thursday, April 25, 2013: SockPuppetForTomruen at English Wikipedia, Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Lunar_eclipse_from_moon-2013Apr25.png

For further information:

“April 25 / April 26, 2013 -- Partial Lunar Eclipse.” Time And Date > Sun & Moon > Eclipses.
Available via Time And Date @ https://www.timeanddate.com/eclipse/lunar/2013-april-25

Espenak, Fred. “Eclipses During 2013.” NASA Eclipse Web Site > Lunar Eclipses.
Available @ https://eclipse.gsfc.nasa.gov/OH/OH2013.html

Espenak, Fred. "Figure 1 Partial Lunar Eclipse of 2013 Apr 25." NASA Eclipse Web Site > Lunar Eclipses > Lunar Eclipse Page > Lunar Eclipses Past and Future: Eclipses During 2013 > Eclipses During 2013: 2013 Apr 25 Partial Lunar Eclipse: Partial Lunar Eclipse of April 25.
Available via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/OH/OHfigures/OH2013-Fig01.pdf

Espenak, Fred. “Lunar Eclipses: 2011-2020.” NASA Eclipse Web Site > Lunar Eclipses.
Available @ https://eclipse.gsfc.nasa.gov/LEdecade/LEdecade2011.html

Marriner, Derdriu. “First of Two 2012 Lunar Eclipses Happens June 4 as Partial Eclipse.” Earth and Space News. Wednesday, May 30, 2012.
Available @ https://earth-and-space-news.blogspot.com/2012/05/first-of-two-2012-lunar-eclipses.html