Moon bigger and brighter, not apocalyptic
Published: 4:33PM Saturday March 19, 2011 Source: ONE News
If you notice the moon looks different this weekend... that's because it is.
The moon will appear bigger and brighter for the next few days - the biggest in 18 years in fact.
This unusually large full moon is known as a super "perigee moon", that's when it's closer to Earth in its orbit.
It's about 49,889 kilometres closer than usual, meaning it will look bigger and brighter than it has since 1993. The next perigee moon won't be until 2029.
This effect is most noticeable when it occurs at the same time as a full moon, said chief NASA scientist James Garvin.
It's so close because the moon's orbit around the Earth is not a perfect circle, but an ellipse. When the Moon's orbit takes it the farthest away from Earth, the moon is at its "apogee."
So not only it be a full moon tonight, but it will also be at its perigee. This month's perigee will put the moon about 8% closer to Earth than usual, and about 2% closer to Earth than the average lunar perigee.
A perigee full moon appears around 14% bigger and 30% brighter than an apogee full moon.
NASA said the upcoming full moon will be of "rare size and beauty". It will rise at about 10pm on Saturday night. But it will appear largest at moonrise this evening, which will be 7:12pm in Gisborne, 7:23pm in Wellington, and 7:27pm to 7.30pm in Auckland, New Plymouth and Christchurch.
It will rise over Invercargill at 7:44pm.
The moon will be in the sky for about 12 hours, and will be setting tomorrow morning in the west.
But according to the experts don't worry about natural disasters, such as earthquakes, associated with the event.
Auckland-based mathematician known as the "Moonman", Ken Ring, has warned the perigee moon will cause another major earthquake in Christchurch, causing some residents to move from the city.
Ring has claimed he predicted Christchurch's deadly February 22 quake by studying the moon.
But critics say there's no scientific proof to back Ring's claims.
"The effects on Earth from a supermoon are minor," said NASA's Garvin.
Although a perigee moon brings with it extra-high "perigean tides," it's nothing to worry about.
In most places, lunar gravity at perigee pulls tide waters only about an inch or so higher than usual, according to NASA.