Tonight is the night of the 2009 Wolf Moon.
Full Moon names started with Native Americans as tribes kept track of the seasons by giving distinctive names to each recurring full Moon. The names actually applied to the entire month in which each occurred.
There was some variation in the names based on tribes. European settlers followed that custom and created some of their own names. Since the lunar month is only 29 days long on the average, the full Moon dates shift from year to year.
The January full Moon name comes from the wolf packs that would howl outside the villages of Native Americans during the hungry, lean, snow-covered winter nights.
Depending on location, some tribes call January the Full Snow Moon, but most tribes applied that name to the next full moon.