Since the cycle of moon phases repeats roughly every 29.5 days (the synodic month), every so often a month has two full moons. The full moon today is the second full moon of August, 2012.
This is sometimes called a blue moon, but the moon isn't really blue when this happens—it's just a normal full moon.
In the photo, the moon is 99.7% illuminated. It's 6 hours before the moment that the moon is 100% full.
