December’s Lunar Eclipse
December 20, 21, and 22 bring together a few big astronomy events. The first is a total lunar eclipse that occurs on December 20 and/or December 21, depending on where you live. Observers who live in the western United States will get to see the event begin on December 20, during late evening hours. Anyone on the eastern half of North America will have to rise in the middle of the night to watch the eclipse. Totality begins at 11:41 p.m. PST and ends at 12:53 p.m. PST on the 21st. For more observing information and times for the eclipse, read the December Night Sky article.
As lunar eclipses can only happen during a full moon, when the sun is opposite Earth and fully illuminating the side of the moon facing us (with our shadow occasionally passing over the moon), it is no surprise that the full moon for December comes on December 21, with the precise moment that the moon is full occurring at 3:13 a.m. EST. The December full moon is sometimes given the name Long Night Moon, which is especially appropriate this year as the full moon falls on the date of the winter solstice for us in the Northern Hemisphere. The solstice occurs at precisely 6:38 p.m. EST on the 21st, ushering in those long, dark, starry nights of winter.
The last big astronomical event over the course of these three days is the Ursid meteor shower on December 22. While not quite as active as the Geminids, which peaked overnight on December 13 and 14, the Ursids still perform admirably, and anyone out a couple nights earlier for the eclipse may spot some Ursids that night too. Comet Tuttle is responsible for this meteor shower, and the "shooting stars" seem to emanate from the constellation Ursa Minor, or Little Dipper, home to the North Star.
-- Kelly Kizer Whitt loves clean, clear, and dark skies. Kelly studied English and Astronomy at the University of Wisconsin-Madison and worked for Astronomy magazine. She is currently the Feature Writer for Astronomy and Space at Suite101.com. You can follow her on Twitter at twitter.com/Astronomommy.