Tuesday, December 29, 2009

Once in a Blue Moon

We have a special surprise coming this New Year's Eve as those in Europe, Africa, Asia and Australia will have the pleasure of seeing a partial eclipse of a Blue Moon.

Most years have twelve full moons which occur approximately monthly, but in addition to those twelve full lunar cycles, each calendar year contains an excess of roughly eleven days. The extra days accumulate, so that every two or three years (on average about every 2.7154 years[1]), there is an extra full moon. The extra moon is called a "blue moon." Different definitions place the "extra" moon at different times.


Hat tip to Neatorama. What's even more interesting is that this blue moon will change to red at the peak of the eclipse.

Since it is a partial eclipse, the moon will just brush past the darkest part of the Earth's shadow, never becoming totally immersed. It will, however, be deep enough into the shadow that shading and reddish color should be visible.

The penumbral eclipse will last just over four hours, starting around 2:15 am on January 1st here in South Korea, and will end around 6:30 am.

The umbral eeclipse, when it will turn partially red, will only last an hour from 3:50 am to 4:50 am on January 1st. Here are the numbers from the NASA eclipse website:

Penumbral = 4h11m03s 17:17 UT - 21:28 UT
Umbral = 0h59m58s 18:52 UT - 19:52 UT

1 comment:

Tao Dao Man said...

WISHING YOU ALL PEACE IN THE NEW YEAR.