Tonight's Perigee Full Moon

In June of 2013 one full mood made the news. They called it “supermoon.” Why? Well, it was 14% bigger and 30% brighter than all of the other full moons that year. The supermoon brought spectators around the world outside to look up at the night sky.  Why does the moon appear to be bigger and brighter? It is because the moon is actually closer to Earth. The moon follows an elliptical path around Earth, one side of this rotation is called perigee and the other, apogee. When a full moon occurs on the perigee side of the Moon’s orbit, the moon appears bigger and brighter because it is approximately 50,000 km closer to earth. For this reason the astronomical community refers to the moon as a "perigee full moon." 2014 is a great year for perigee full moons. Tonight, August 10th, sky watchers can enjoy what headlines have dubbed “an extra-super moon.” Tonight's moon is expected to be 16% larger and 30% brighter than usual.

This is because the moon becomes full during the same hour as perigee. On September 9th the moon will become full again on the same day as perigee, however not the same hour. A supermoon also occurred last month on July 12th. 

Source: National Geographic