December 2010 lunar eclipse

A total lunar eclipse occurred at the Moon’s descending node of orbit on Tuesday, December 21, 2010, with an umbral magnitude of 1.2576. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A total lunar eclipse occurs when the Moon's near side entirely passes into the Earth's umbral shadow. Unlike a solar eclipse, which can only be viewed from a relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of Earth. A total lunar eclipse can last up to nearly two hours, while a total solar eclipse lasts only a few minutes at any given place, because the Moon's shadow is smaller. Occurring about 4 days before apogee (on December 25, 2010, at 7:15 UTC), the Moon's apparent diameter was smaller.

This eclipse was notable in that it coincided with the date of the Winter solstice in the Northern Hemisphere and Summer solstice in the Southern Hemisphere. It was the first total lunar eclipse to occur on the day of the Northern Winter Solstice (Southern Summer Solstice) since 1638, and only the second in the Common Era.