Monday, February 18, 2008
Lunar Eclipse: February 20th
Upcoming Lunar Eclipse
Taken from Space.Com
On Wednesday night, Feb. 20, for the third time in the past year, the moon will become completely immersed in the Earth's shadow, resulting in a total lunar eclipse. As is the case with all lunar eclipses, the region of visibility will encompass more than half of our planet. Nearly a billion people in the Western Hemisphere, more than 1.5 billion in Europe and Africa, and perhaps another half-billion in western Asia will be able to watch — weather permitting — as the brilliant mid-winter full moon becomes a shadow of its former self and morphs into a glowing coppery ball.
Almost everyone in the Americas and Western Europe will have a beautiful view of this eclipse if bad weather doesn't spoil the show. The moon will be high in a dark evening sky as viewed from most of the United States and Canada while most people are still awake and about.
Moreover, this eclipse comes with a rare bonus. The planet Saturn (magnitude +0.2) and the bright bluish star, Regulus (magnitude +1.4) will form a broad triangle with the moon's ruddy disk.
Careful watchers will notice the moon changing its position with respect to the star and planet as it moves eastward through the Earth's shadow.
Saturn's position will also depend somewhat on your location. Seen from North America, the great ringed planet will be 3.5 degrees above and to the left of the moon's center at mid-totality (3:26 Universal time February 21st). At the same moment, Regulus will sit just 2.8 degrees above and to the right of the moon.
Some old-time astronomy buffs may remember from 40 years ago a total lunar eclipse with the moon sitting only about a degree from Spica — a gorgeous celestial tableau! More recently, in 1996, a totally eclipsed moon passed within 2 degrees of Saturn.
But this upcoming double event will be the only one of its kind occurring within the next millennium!
The eclipse will begin when the moon enters the faint outer portion, or penumbra of the Earth's shadow. The penumbra, however, is all but invisible to the eye until the moon becomes deeply immersed in it. Sharp-eyed viewers may get their first glimpse of the penumbra as a delicate shading on the left part of the moon's disk about 20 minutes before the start of the partial eclipse (when the round edge of the central shadow or umbra, first touches the moon's left edge). During the partial eclipse, the penumbra should be readily visible as a dusky border to the dark umbral shadow.
The moon will enter Earth's much darker umbral shadow at 1:43 on Feb. 21 by Greenwich or Universal time, which is 8:43 p.m. on Feb. 20 in the Eastern time zone, 7:43 p.m. Central time, 6:43 p.m. Mountain time and 5:43 p.m. Pacific time.