Data for this Eclipse:
Starts very late on Monday, December 20, 2010 and finishes before dawn on Tuesday, December 21, 2010.
Penumbral Begins: 05:29:17 UT
Partial Begins: 06:32:37 UT
Total Begins: 07:40:47 UT
Greatest Eclipse: 08:16:57 UT
Total Ends: 08:53:08 UT
Partial Ends: 10:01:20 UT
Penumbral Ends: 11:04:31 UT
Mechanics of Lunar Eclipses:
A lunar eclipse occurs when the moon moves into the Earth's shadow. This can happen only at two times during the year, usually in June and December. The moon's orbit around the Earth does not lie flat (in the same plane) as the Earth's orbit around the sun. As the Earth travels around the sun, twice each year the orbit of the moon aligns so that the point where they cross is located along the line passing from the sun to the Earth. These are the times when we can have lunar eclipses. Near that time, when the moon moves into that location on the opposite side of the Earth from the sun, we can have a lunar eclipse.
Sometimes, the alignment is not perfect. When this happens we see other types of lunar eclipses. If part of the moon passes into the Earth's shadow we see a Partial Eclipse. And sometimes, the moon misses the inner shadow completely and only passes through the Penumbra. When this happens we have a Penumbral eclipse. At these times, the moon dims slightly, but most people would not even notice the change.
|The Danjon Scale:|
The Danjon Scale is used to note the darkness of a Lunar Eclipse. Eclipses seldom turn the moon black. The reason for the reddish coloration is that red light from the sun gets to the moon by curving through the Earth's atmosphere.
0 - Very dark eclipse. Moon almost invisible, especially at mid-totality.
1 - Dark Eclipse, gray or brownish in coloration. Details distinguishable only with difficulty.
2 - Deep red or rust-colored eclipse. Very dark central shadow, while outer edge of umbra is relatively bright.
3 - Brick-red eclipse. Umbral shadow usually has a bright or yellow rim.
4 - Very bright copper-red or orange eclipse. Umbral shadow has a bluish, very bright rim.
A Brief Note on Solar Eclipses:
Solar Eclipses occur when the moon passes between the sun and the Earth during those same times during the year (2 weeks before or after the lunar eclipse). Solar Eclipses come in three types: Total (no sun is visible), Partial (some of the sun is visible), and Annular (a ring of sun is visible around the edges of the moon: a ring). Unlike a lunar eclipse, total solar eclipses are only visible along a small line on the Earth's surface.
The next Total Solar Eclipse visible in North American will be on August 21, 2017. The path goes through South Carolina, Tennessee, Missouri, Nebraska, Wyoming, Idaho, and Oregon. Road trip!!! the next Total Solar Eclipse will be on November 13, 2012 and will be viewable in the South Pacific.