Thanks to a fluke of orbital mechanics that brings the moon closer to Earth than that it has been in more than 18 years, the biggest full moon of 2011 will occur on Saturday, leading some observers to dub it a "supermoon."
On Saturday afternoon at 3 p.m. Eastern Daylight Time, the moon will arrive at its closest point to the Earth in 2011: a distance of 221,565 miles (356,575 kilometers) away. And only 50 minutes earlier, the moon will officially be full. [Photos: Our Changing Moon]
At its peak, the supermoon of March may appear 14 percent larger and 30 percent brighter than lesser full moons (when the moon is at its farthest from Earth), weather permitting. Yet to the casual observer, it may be hard to tell the difference.
The supermoon will not cause natural disasters, such as the Japan earthquake, a NASA scientist has stressed.
Spotting the supermoon
The moon has not been in a position to appear this large since March 1993.
In December 2008, there was a near-supermoon when the moon turned full four hours away from its perigee – the point in its orbit that is closest to Earth. But this month, the full moon and perigee are just under one hour apart, promising spectacular views, depending on local conditions. [Infographic: 'Supermoon' Full Moons Explained]