Sunday, December 19, 2010

Nature Guide: Winter Solstice Lunar Eclipse

Photo: NASA

Winter begins on Tuesday. Early that morning—for the first time in 372 years—we will experience a total eclipse of the Moon. Our Nature Guide Jon Latimer tells us more about this remarkable event.

"This year winter officially begins in the Northern Hemisphere at 6:38 pm EST on December 21, 2010, the shortest day and longest night of the year. This is the winter solstice, when the sun reaches its lowest point in the northern sky. But for the first time since 1638, the morning of December 21 will offer an additional astronomical treat: a lunar eclipse. The full Moon will pass almost dead center through Earth's shadow.

"The eclipse begins Tuesday morning at 1:33 am EST. At first the Earth's shadow will appear as a dark red sliver at the edge of the lunar disk. Gradually that sliver will expand to cover the whole face of the Moon, which is known as totality. Totality will be reached at 2:41 am EST and will last 72 minutes.

"During the moments of total coverage, an eerie amber light will color our landscape an unusual coppery red. This reddish color comes from sunlight that passes around the Earth's edge and is reflected back to Earth by the Moon while the eclipse is underway.

"It will be cold, so if you want to go out for a quick look, wait until 3:17 am EST. That's when the Moon will be in deepest shadow and will display the most fantastic shades of coppery red. You may want to catch this sight while you can. The next time a lunar eclipse occurs on the winter solstice is in 2094."