Science glossary film: Eclipse, lunar

An alignment of the Earth directly in between the Sun and the Moon, so that the Earth's shadow falls on the Moon and obscures all or part of it. Because of the way the three objects have to line up, lunar eclipses always fall on the night of a full Moon. They happen about twice a year, total lunar eclipses less often. Unlike a solar eclipse, a lunar eclipse can be seen from anywhere on the night side of Earth.

Because of the way the three objects have to line up, lunar eclipses always fall on the night of a full Moon. They happen about twice a year, total lunar eclipses less often. Unlike a solar eclipse, a lunar eclipse can be seen from anywhere on the night side of Earth.