Jimmy Westlake: 2010: A year of eclipses
January 6, 2010
When the full moon rose over the treetops on May 15, 2003, about half of it was eclipsed by the Earth's shadow, as seen in this telescopic image. On June 26, a similar view will greet early risers as the half-eclipsed full moon sets at sunrise. A total eclipse of the moon also will be seen from North America on Dec. 21.
Steamboat Springs — If I had to astronomically characterize the year 2010, I would call it "The Year of Eclipses." We open the year with an eclipse, and we close out the year with an eclipse, with two other eclipses in between!
The first of four eclipses in 2010 is an annular, or ring, eclipse of the sun Jan. 15. A ring eclipse happens when the Earth is near its closest point to the sun, so that the sun looks big in our sky, and the moon is near its farthest point from Earth, so that it looks small in our sky.
Under these conditions, the moon appears too small to totally cover the sun, leaving a ring of fire visible around the edge of the moon. At no time is a ring eclipse safe to look at without a protective solar filter.
Unfortunately for us, this eclipse is visible only from a narrow swath of the Earth that begins in East Africa, crosses the Indian Ocean and winds up in Southeast Asia. The annular solar eclipse of May 20, 2012, will come much closer to Colorado and offer us a chance to see a ring eclipse from right here in the American southwest. Still, if you find yourself in Sri Lanka on Jan. 15, pull out that solar filter and look up!
The second eclipse of 2010 is a partial eclipse of the moon the morning of June 26. This one is visible from Colorado. When the full hay moon rises at sunset June 25, it will look like any other gorgeous full moon, but beginning at 4:17 a.m. the next day, the northern half of the moon will pass into the Earth's dark shadow. The dark "bite" out of the lunar "cookie" will be greatest at 5:39 a.m., just as the moon sets in the southwest and the sun breaks the horizon in the northeast. From Colorado, most of this eclipse will be seen during morning twilight. It isn't every day that you get to see a partially eclipsed moon in a colorful predawn sky.
The third eclipse of 2010 is the ultimate eclipse, a total eclipse of the sun July 11. For this eclipse, the moon will appear slightly larger than the sun so that it can completely cover the sun's blinding disc for as long as five minutes and 20 seconds of totality. It is during these precious moments of totality that the sun's beautiful corona and chromosphere flash into view. Astronomers and eclipse chasers from all across the globe will converge on the eclipse zone to spend these few minutes photographing, studying and just plain staring at what is arguably the most awesome sight in nature. But, alas, this spectacular eclipse is not visible from anywhere in North America. In fact, the moon's shadow will sweep across mostly open waters of the South Pacific, passing over a few exotic islands before crossing the southern tip of South America. This is the last total eclipse of the sun visible anywhere on earth until Nov. 13, 2012. July 2010 would be a great time to take that dream vacation to Tahiti.
The full moon that occurs before dawn Dec. 21 will be an unusual fourth full moon of fall, for which there is no traditional name. The named moons of fall — harvest moon, hunter's moon and long night moon — will have already occurred. Such "nameless" full moons usually are dubbed "blue moons." This blue moon is even more exceptional because it will be totally eclipsed by the shadow of the Earth. All of North America will be perfectly placed to view the entire eclipse. The eclipse will begin at 12:32 a.m. Mountain Standard Time and will progress until totality begins at 1:41 a.m. 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 at the feet of the Gemini Twins, very close to the star cluster M35. The binocular view of the dull, red full moon beside the glittering star cluster will be breathtaking. Totality will end at 2:53 a.m., and the moon will completely emerge from the Earth's dark shadow at 4:01 a.m. What a way to finish off 2010!
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. For a full-color calendar of celestial events in 2010 featuring some of Jimmy's best astrophotos, check out "Jimmy's 2010 Cosmic Calendar" on his Web site, http://www.jwestlake.com.