When the full moon rises on Saturday night, it will be bigger and brighter than at any time for almost 20 years -- and that is setting off alarm bells for those who make it their business to warn of impending doom.

The moon's orbit around the earth is not a perfect circle, and it reaches its point of closest approach, or perigee, once every month. This month, however, is special, because the moon will reach that point -- a mere 221,565 miles away -- with 50 minutes of when it is also at its moment of maximum fullness.

These two events are occurring more closely together than at any time since 1993, and the combination will cause the full moon to appear 14% larger and 30% brighter than on average.

The tides will also be slightly higher than normal during the day or two following, a connection that might come as a surprise to Fox News host Bill O'Reilly. O'Reilly famously insisted to the representative of an atheist group a few months back, "Tide goes in, tide goes out. Never a miscommunication. You can't explain that. You can't explain why the tide goes in."

Although the "super moon" may be able to affect the tides, however, scientists like John Bellini of the US Geological Survey emphasize that it had nothing to do with last week's earthquake in Japan.

"The Japanese earthquake thus points to the fact that astrology — an astrologer was the first to suggest the supermoon could be a threat — isn't a science," one blog reported after speaking with Bellini. "That this earthquake occurred a week before an astronomical event is mere coincidence. The vast majority of earthquakes, tsunamis, volcanic eruptions and natural disasters do not follow the lunar cycle or tides. 'This is something that builds up over hundreds of years,' Bellini told Life's Little Mysteries."

The astrologer in question is Richard Nolle, who claims that “SuperMoons are noteworthy for their close association with extreme tidal forces working in what astrologers of old used to call the sublunary world: the atmosphere, crust and oceans of our home planet – including ourselves, of course. From extreme coastal tides to severe storms to powerful earthquakes and volcanic eruptions, the entire natural world surges and spasms under the sway of the SuperMoon alignment – within three days either way of the exact syzygy, as a general rule.”

Scientific debunking has not prevented Nolle's predictions from racing around the Internet and being taken up by other websites -- such as one that explains helpfully, "The Siddha Esoteric Technology method of Disaster Prevention often does not make any sense to the rational mind. However the Siddha’s swear by their efficacy."

An article from space.com, however, concludes more philosophically, "Most natural disasters have nothing to do with the moon at all. The Earth has a lot of pent up energy, and it releases it anytime the buildup gets too great. The supermoon probably won't push it past the tipping point, but we'll know for sure, one way or the other, by March 20."

Image courtesy of Wikimedia Commons.