The biggest full moon of the year, a so-called "supermoon," will take center stage when it rises this weekend, and may interfere with the peak of an annual meteor shower created by the leftovers from Halley's comet. The supermoon of 2012 is the biggest full moon of the yearand will occur on Saturday (May 5) at 11:35 p.m. EDT (that's 8:35 PDT "real time"), though the moon may still appear full to skywatchers on the day before and after the actual event AND AFTER THAT TIME. At the same time, the annual Eta Aquarid meteor shower will be hitting its peak, NASA scientists say. "Its light will wash out the fainter Eta Aquarid meteors," NASA meteor expert Bill Cooke of the Marshall Space Flight Center told SPACE.com in an email. Still, Cooke said there's a chance that the brightest fireballs from the meteor display may still be visible.
A supermoon occurs when the moon hits its full phase at the same time it makes closest approach to Earth for the month, a lunar milestone known as perigee. Scientists also refer to the event as a "perigee moon," according to a NASA video on the 2012 supermoon.
That's exactly what will happen on Saturday, when the moon will swing within 221,802 miles (356,955 kilometers) of Earth — its closest approach of the entire year. Because the moon's orbit is not exactly circular, there is a 3-percent variation in its closest approaches to Earth each month. The average Earth-moon distance is about 230,000 miles (384,400 km). With May's full moon timed with the moon's perigee, it could appear 14 percent bigger and 30 percent brighter than other full moons of 2012, astronomer Tony Phillips explained in a NASA video. There is absolutely no chance the supermoon will threaten Earth.