Lunar Eclipse
Filed Under (Star Gazing) by Deltrice on 27-08-2007
Tagged Under : astronomy, star_gazing
Lunar Eclipse
The western United States is in for a skywatching treat tonight: a total lunar eclipse. The eastern half of the country will see part of the eclipse before the Moon sets around sunrise.
A lunar eclipse takes place when the full Moon — which lines up directly opposite the Sun — moves through Earth’s shadow. The Moon’s orbit around Earth is tilted a little, so most of the time, the Moon passes above or below the shadow. An eclipse occurs only when the geometry is just right — as it is tonight.
The eclipse begins at 2:54 a.m. Central Daylight Time, when the lunar disk first touches the outer portion of the shadow, called the penumbra. The penumbra is so faint, though, that most people won’t even notice it.
You will notice when the Moon moves into the central part of the shadow, called the umbra. It takes a dark “bite” out of the Moon — a bite that grows larger as the Moon moves deeper into the shadow. The Moon will first touch the umbra at 3:51 a.m. It’ll be fully immersed in the umbra an hour later, and remain in full eclipse for an hour and a half.
From the East Coast, the Moon will still be fully eclipsed as it sets. From points farther west, though, you’ll be able to see the Moon begin to emerge from the shadow, as more of the lunar disk returns to sunlight. It’ll fully emerge from the umbra at 7:24 a.m., so the Moon will still be in view from the western Great Plains to the Pacific Coast.
