Astroprof sets the record straight on Blue Moons. He offers a variety of definitions of what a Blue Moon is, when it occurs, as well as a number of misconceptions on what a Blue Moon is not. Furthermore, he looks at the history of the Blue Moon and its development in folklore.

Other posts on this topic:

• Wikipedia: Blue Moon
• Blue Moon
• What's a Blue Moon?
• The Truth Behind This Month's Blue Moon
• Blue Moon Myths