Blue Moon
What exactly is a "blue moon?" Contrary to its title, it doesn't refer to the moon's color, but its rarity. A "blue moon" occurs when a second full moon appears in the same calendar month. Onlookers should take a good look at it because it won't occur again until July 2015. Typically, "blue moons" only happen every 2.7 years.
Although it doesn't differ much from the full moon that is usually seen once a month, this event has historic significance.
Uploaded on September 01, 2012