A lunar eclipse occurs when the Sun, Earth and Moon are totally
aligned. During a lunar eclipse, the Earth blocks sunlight from
reaching the moon. Lunar eclipses don't happen every time the Moon
is full because the orbit of the Moon is inclined 5°. Usually the
moon is either north or south of the Earth's shadow. Lunar eclipses
happen twice a year generally, though the total lunar eclipses don't
happen as often. It is possible for an eclipse to be partial or
penumbral. The shadow of the Earth is divided into two parts: the
umbra and the penumbra. The umbra is the area where the sun's
radiation is totally blocked by the Earth. In the Penumbra, the
sun's radiation is only partially blocked. In a penumbral eclipse
the moon only enters the penumbra; in a partial eclipse the moon
enters the umbra, but not fully. Only in a total eclipse does the
moon fully enter the umbra. On August 28, 2007 a total eclipse
occurred.
This dataset simulates what the total lunar eclipse of August
2007 looked like. The picture above contains the path of the moon
and the exact times of each stage. The whole eclipse lasted one
hour and thirty one minutes. When the moon enters the penumbra, the
moon is darkened, and then when it enters the umbra it turns a
reddish-copper color. The coloration is the result of deflected
sunlight through the Earth's atmosphere. For more information on
lunar eclipses and to see when the next will occur, check
here.