18 March 2011

Extreme Super-Moon

Saturday 19 March is one of those evenings that sky gazers have been anticipating for a long time. A rare lunar phenomenon is about to happen. You may not even notice it yourself if you are simply a casual observer but tomorrow night the moon will appear larger and brighter than normal.

The moon has not been this close to the Earth for eighteen years. Some astrologists refer to this as a super-moon but there are even those who are calling tomorrow night’s moon an extreme super-moon because the moon will also be at the fullest part of its sequence. The real name for the term is rather different – astrological purists refer to it as a lunar perigree.

For many this is the opportunity to gaze in awe at the beauty of our lonely satellite. However, there are the doomsayers too. They maintain that when the moon is at its closest to us then the increased gravitational pull of the moon does strange things to the Earth. Many are already pointing a finger towards Japan and blaming the perigree for the earthquake and tsunami disaster there.

A number of astrologers have also made dire predictions for tomorrow evening, from further earthquakes to huge storms and tides. Other historical weather anomalies and associated disasters (in human terms) have also been blamed on super-moons. Astrologers and astronomers are, however, quite different beats. The bulk of the scientific world is sceptical and says that there is one important thing missing before people assume the moon is causing these disasters: cold hard evidence.

As the moon’s orbit around the earth is elliptical the difference between its furthest and nearest points would, at first glance, be cause for concern (and if the distance between the two happened overnight it would most certainly be a time to, well, panic). 254,000 miles is the furthest the moon is ever away from the earth. At is closest it is still 220,000 miles away but that means that it is closer to us by 34,000 miles. That is some distance – and perhaps you can see why astrologers take the perigree as a time for disaster to occur.

While it is true that tidal forces increase by about fifteen percent during a lunar perigree that does not mean that tides will be higher by the same percentage. The average perigree tidal rise is around an inch – nothing much to throw your arms up in horror there, then! In fact the dire effects that the moon is said to have on the weather during its perigree are largely a creation of the blogosphere. Here at Kuriositas we are happy to stand up and be counted when it comes to debunking what amounts to lunatic lunar conspiracy theory!

Just in case you do believe the ‘theories’ and think that the recent Japanese earthquake was caused by the moon, consider this. When the earthquake happened the moon was at its furthest point away from us – at what is called the lunar apogee. Now, I’m not a rocket scientist (more of a space cadet in truth), but...

However, and there is some irony here – there is some evidence to suggest that in fact the Earth is responsible for earthquakes on the moon. There was research done by NASA in the 1970s and they came to that very conclusion. So, Commander John Koenig would have to choose the site for Moonbase Alpha very carefully.
So, myth debunked – but it does give us a great excuse to reproduce these marvellous pictures!