A total lunar eclipse on December 21, 2010, will be the last eclipse of the year. This will be second of two lunar eclipses in 2010. The last time a total lunar eclipse occurred was on February 21, 2008.
Where Will the Eclipse be Visible?
The December 21 lunar eclipse will be visible to observers in North America and western South America. The winter constellations are well placed for viewing during totality so a number of bright stars can be used for magnitude comparisons. Observers along South America’s east coast miss the eclipse’s late stages because they occur after moonset.
Most of Europe and Africa experience moonset while the eclipse is in progress. Only northern Scandinavians can catch the entire event from Europe. The moon rises in the eclipse for observers in eastern Asia. The eclipse will not be visible from southern and eastern Africa, the Middle East or southern Asia. The moon will be situated in the constellation Taurus, close to the border with Gemini, and near the most northerly point in the moon’s orbit at that time of the year.
When will the Eclipse Occur?
The eclipse’s total phase lasts for 72 minutes. The penumbral eclipse begins at 05:29:17 Universal Time (UT) and the partial eclipse starts at 06:32:37 UT. The total eclipse begins at 07:40:47 UT and the point of the greatest eclipse occurs at 08:16:57 UT. The moon lies near the zenith for observers in southern California and Baja Mexico at the instant of the greatest eclipse. The umbral magnitude peaks at 1.2561 as the moon’s southern limb passes 2.8 arc minutes north of the shadow’s central axis. Therefore, the moon’s southern half will seem much darker than the northern half because it lies deeper in the umbra.
Since the moon samples a large range of umbral depths during totality, its appearance will change dramatically with time. The total eclipse ends at 08:53:08 UT, followed by the end of the partial eclipse at 10:01:20 UT. The penumbral eclipse ends at 11:04:31 UT.