Repost - I had a paste and copy error in the first post. - K ---------- Yahoo.news has been circulating a story on this month's March 19 extreme perigee of the Moon quoting an astrologer making predictions of dire consequences from the pass. That entertainment news report has gained traction with today's Japanese earthquake. Here are some background facts to answer your non-astronomical friend's questions on the supermoon story. Looking at Meeus's Mathematical Astronomy Morsels, Sec.2, the distribution of extreme perigrees of the Moon are quite frequent. With the ``mean'' distance to the Moon at about 384,000 km, and Meeus tabulated the distribution and frequency of lunar perigrees for 80 years between 1960 to 2040. Extreme lunar perigees have nothing to do with the 18 year Saros cycle. Extreme lunar perigees occur as the Sun and Earth align to pull the Moon closer in conjunction with the lunar ``natural'' semi-minor axis. Curiously, unlike other natural phenomena, the extremes of perigees below 370,500 km are not normally distributed; they bi-modal. More perigees are grouped near the endpoints of 356,000 km and 370,500 km. Taking the lowest 10 percent of extremes between 356,000 km and 357,500 km, there are actual and predicated 181 perigree extremes between 1960 and 2040 (960 months). This implies an extreme perigee (in terms of the bottom 10 percent) occurs on average once every 5.3 months. There will be 82 extreme perigees between 356,500 km and 365,700 km, or about 1 extreme perigee every 11 months. Maybe the extra 133 kilometers between 356,577 and 356,700 km matter, but I doubt it. This astrologer predication is another in the category of overstated planetary alignments, e.g. - when three planetary bodies align (e.g. the Moon, Jupiter and Saturn), the astrologers issue ``death-from-above'' press releases. On a different note supporting this notion of volcanoes and extreme lunar perigrees, Donna O'Meara (Stephen O'Meara's wife), made a career from traveling around the world and photographing volcanos. Stephen O'Meara is known for claiming a possible relationship between the Moon's close passes, volcanoes and earthquakes, an association that Bad Astronomy's Phil Plait questions - http://blogs.discovermagazine.com/badastronomy/2006/08/09/mooning-a-volcano/ Some of you may remember O'Meara's trip to a volcano in 2001 at a perigee to test this idea and great footage of the volcano starting to erupt as Stephen and wife were hiking up to the rim. It was covered in an old National Geographic TV broadcast - http://news.nationalgeographic.com/news/2002/02/0215_020215_volcanohunter.ht... Today's Bad Astronomy entry concerns debunking concerns that the ``supermoon'' caused today's Japan's earthquake. Phil Plait makes the common sense point that the Moon was nowhere near perigee last night - it was at apogee on March 6. http://blogs.discovermagazine.com/badastronomy/ This notion of the close moon causing volcanoes to erupt also comes up in the news periodically with respect to an active Philippino volcano Mayon (in 2006 and Dec. 2009), e.g. - http://www.dailymail.co.uk/news/article-399776/Full-moon-spark-Philippine-vo... In summary, these extreme perigees have happened many times through my some 50 plus years on this earth, and I haven't been killed by one yet. -:) Clear Skies - Kurt