A time lapse video of a total lunar eclipse in December 2010, by William Castleman. This occurs when the Earth moves in between the Sun and the Moon. As the Earth prevents most of the Sun’s rays from reaching the Moon, it is cast into darkness. The red color is the result of some of the Sun’s rays passing through the Earth’s atmosphere.

He used a four inch refracting telescope with an equatorial mount to follow the moon. Still photographs were taken every 20 seconds with a camera attached to the telescope. The photographs were then assembled into the time lapse video.