Monday, March 21, 2011

Supermoon: March 19

A supermoon (or more accurately a perigee-syzygy of the Earth-Moon-Sun system) occurs when the full moon coincides with the point of the moon's orbit that is closest to Earth. The term "perigee" means the point when the moon is closest to the Earth, and syzygy is a full or new moon. Hence, perigee-syzygy = supermoon.

Saturday, March 19, 2011

Thursday, March 3, 2011

Study aids