The Comet Hartley 2 Visible Today in Night Sky

Backyard stargazers with a telescope and a clear night's sky can now examine the comet that in a little over two weeks will turn out to be only the fifth in history to be imaged close up. Comet Hartley 2 will come within 17.7 million kilometers (11 million miles) of Earth this Wed., Oct. 20 at noon PDT (3 p.m. EDT).

NASA's EPOXI mission will come within 700 kilometers (435 miles) of Hartley 2 on Nov. 4. "On October 20, the comet will be the closest it has ever been since it was discovered in 1986 by Australian astronomer Malcolm Hartley," said Don Yeomans, head of NASA's Near-Earth Object Office at the Jet Propulsion Laboratory in Pasadena, Calif. and a member of the EPOXI science team. "It's strange for a comet to approach this closeness. It is pleasant of Mother Nature to give us a preview before we see Hartley 2 in all its cometary beauty with some great close-up images less than two weeks later."

Comet Hartley 2, also known as 103P/Hartley 2, is a comparatively small, but very active periodic comet that orbits the sun once every 6.5 years. From dark, pristine skies in the Northern Hemisphere, the comet should be visible with binoculars as a fuzzy object in the constellation Auriga, passing south of the bright star Capella. Viewing of Hartley 2 from high ambient light locations including urban areas may be more difficult.

In the early morning hours of Oct. 20, the optimal dark sky window for mid-latitude northern observers is under two hours in length. This dark interval will occur between the time when the nearly-full moon sets at about 4:50 a.m. (local time) and when the morning twilight begins at about 6:35 a.m. By October 22, the comet will have passed through the constellation Auriga. It will continue its journey across the night sky in the direction of the constellation Gemini. .