• According to U.S. clocks, May 5, 2012 features the closest and largest full moon of this year. Calendars say May 6, by the way, for this same close full moon as seen from Europe, the Middle East, Africa and Asia. We astronomers call this sort of close full moon a perigee full moon. The word perigee describes the moon's closest point to Earth for a given month. But last year, when the closest and largest full moon occurred on March 19, 2011, many used a term we'd never heard: supermoon. We've heard this term again at this 2012 close full moon. What does it mean ex

actly? And how special is the May 5, 2012 supermoon?
• Largest full moon of 2012 will obscure Eta Aquarid meteors
• The word supermoon didn't come from astronomy. Instead, it came from astrology. Astrologer Richard Nolle of the website astropro.com takes credit for coining the term supermoon. In 1979, he defined it as:
• …a new or full moon which occurs with the moon at or near (within 90% of) its closest approach to Earth in a given orbit (perigee). In short, Earth, moon and sun are all in a line, with moon in its nearest approach to Earth.
• By this definition, according to Nolle:
• There are 4-6 supermoons a year on average.
• That doesn't sound very special, does it? In fact, tonight's full moon lines up much more closely with perigee - the moon's closest point to Earth - than Nolle's original definition. The 2012 May full moon falls within an hour of perigee, the moon's closest point to Earth for this month. At perigee, the moon lies only 356,955 kilometers (221,802 miles) away. Later this month, on May 19, the moon will swing out to apogee - its farthest point for the month - at 406,448 kilometers (252,555

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