Partial eclipse of the Moon on Dec 31st, 2009

On December 31st, 2009 most of us will be treated by a partial lunar eclipse. Indeed, the Moon will be darkened by part of Earth’s shadow on this year’s last Full Moon, and this month’s second Full Moon (sometimes called a ‘Blue Moon’). Only the Americas will not be able to witness this eclipse.

Details about visibility of this eclipse can be found on a bulletin by Fred Espenak, NASA or on Wikipedia. Timewise the eclipse will progress as follows:

1. P1 (Moon enters the penumbra of the Earth: start of the eclipse): 17h17 UTC
2. U1 (Moon enters the umbra of the Earth): 18h52 UTC
3. Maximum around 19h22 UTC (halfway between U1 and U4)
4. U4 (Moon leaves the umbra of the Earth): 19h52 UTC
5. P4 (Moon leaves the penumbra of the Earth, end of the eclipse): 21h28 UTC

When the Moon enters the Penumbra it will slowly get darker but will still be very well visible. Once the umbral eclipse kicks in, you will see that one of the edges of the moon will get substantially darker. Between 19h00 UTC and 19h45 UTC the eclipse should be very easy to notice. Weather permitting of course

To translate from UTC to your local time zone you will have to add/remove a couple hours. Example: 17h00 UTC translates to 17h00 local time in London (UTC+0), 18h00 in Brussels (UTC+1), 19h00 in Helsinki (UTC+2) etc.