Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2010 January 1



Not a Blue Moon

Credit & Copyright: Stefano De Rosa

Explanation: This bright Full Moon was captured on December 2nd, shining above a church overlooking the River Po, in Turin, Italy. It was the first Full Moon in December. Shining on celebrations of New Year's Eve, last night's Full Moon was the second Full Moon of December and so fits the modern definition of a Blue Moon - the second Full Moon in a month. Because the lunar cycle, Full Moon to Full Moon, spans 29.5 days, Blue Moons tend to occur in some month about every 2.5 years. Shining in the glare just above and right of December's first Full Moon is the Pleiades star cluster.