Our final full moon of autumn occurs just before dawn on Tuesday December 21, 2010. This full moon traditionally is called the Long Night’s Full Moon because it falls close to the time of the winter solstice when the days are short and the nights are, indeed, very long. Our winter solstice — the moment that winter begins in the northern hemisphere — occurs at 4:38 pm on December 21. After that, the days will start getting longer again as we move toward spring.
This year’s Long Night’s Full Moon is more exceptional than most because it will be totally eclipsed by the shadow of the Earth. All of North America will be perfectly placed to view this entire eclipse. The partial phase of the eclipse will begin at 11:32 pm MST on Monday night December 20, when the southern edge of the full moon
enters the dark, umbral shadow of the Earth. Over the next hour, the dark bite out of the moon will grow until the moon is completely engulfed by the shadow. The total phase of the eclipse begins at 12:40 am Tuesday morning. For 72 minutes, the full moon will look like a glowing, orange ember against the starry sky as the reddened light of every sunrise and sunset on Earth is projected onto the Moon. The Moon will be positioned just above the magnificent star pattern of Orion, near the feet of the Gemini Twins and very close to the star cluster M35. The binocular view of the red, eclipsed moon beside the glittering M35 star cluster will be breathtaking. Totality ends at 1:53 am and the full moon will completely emerge from the Earth’s dark shadow at 3:01 am.
Total lunar eclipses are not particularly rare. One is visible from somewhere on Earth almost every year. The last one visible from northwest Colorado was February 20, 2008. The next one after this year’s eclipse will be on April 15, 2014, followed that same year by a second total lunar eclipse on October 8. We will have a brush with a total lunar eclipse next December 10, 2011, when the moon sets just moments before totality begins
.
It’s interesting to imagine what a total lunar eclipse would look like from the Moon’s perspective. An astronaut on the Moon would be watching a total eclipse of the Sun, as the Earth covers more and more of the solar disk. During totality, the astronaut would see a brilliant red ring of light surrounding the dark ball of the Earth as rays from the hidden Sun stream through the Earth’s atmosphere and illuminate the darkened moon.
What a spectacular way to finish off a year of amazing celestial events! ***
Professor Jimmy Westlake teaches astronomy and physics at Colorado Mountain College’s Alpine Campus. He is an avid astronomer whose photographs and articles have been published all around the world. His “Celestial News” column appears weekly in the Steamboat Today newspaper and his “Cosmic Moment” radio spots can be heard on local radio station KFMU. Also, check out Jimmy’s astrophotography website at www.jwestlake.com.