Saturday, March 19, 2011

Saturday night, full moon in perigee

The moon is in elliptical orbit around the earth. About every 18 years, the moon comes relatively close to the earth and that is called perigee. Apogee is when it’s at the farthest point from the earth so the moon appears considerably smaller on those instances.

Contrary to some reports circulating the Internet, perigee moons do not trigger natural disasters. A perigee with a full Moon brings with it extra-high “perigean tides,” but this is nothing for concern, according to NOAA. In most locations, lunar gravity at perigee pulls tide waters only a few centimeters (an inch or so) higher than usual. Local geography can amplify the effect to about 15 centimeters (six inches)–not exactly a great flood.


The last full moon appearing so large and close to Earth occurred in March of 1993.

Tags: supermoon, supermoon march 19, 超級月亮, 超级月亮, moon