Dogman
18th October 2010, 10:22 AM
http://spaceweather.com/ (http://spaceweather.com/)
TIME TO SEE COMET HARTLEY: For backyard stargazers, the next few nights are the best time to see green Comet 103P/Hartley 2 as it approaches Earth for an 11-million-mile close encounter on Oct. 20th. Set your alarm for the dark hours before dawn, go outside, and look straight up. You will find Hartley 2 not far from the bright star Capella: sky map. Although the comet is barely visible to the unaided eye, it is easy to find in binoculars and looks great through a backyard telescope.
Last night, Filipe Alves of Portalegre, Portugal, obtained the following long-exposure image using an 8-inch telescope and a KAF-8300 refrigerated CCD camera. It shows the comet's vast green atmosphere and an auburn tail of dust:
Many readers have asked, why is the comet green? Answer: Hartley 2's green color comes from the gases that make up its Jupiter-sized atmosphere. Jets spewing from the comet's nucleus contain cyanogen (CN: a poisonous gas found in many comets) and diatomic carbon (C2). Both substances glow green when illuminated by sunlight in the near-vacuum of space.
NASA scientists say 103P/Hartley 2 is one of the most active comets they've seen, with copious outgassing from jets in the nucleus. Amateur astronomers are encouraged to monitor the action and submit their images here.
http://www.spaceweather.com/submissions/pics/f/Filipe-Alves-103PHartley_1287400018.jpg
TIME TO SEE COMET HARTLEY: For backyard stargazers, the next few nights are the best time to see green Comet 103P/Hartley 2 as it approaches Earth for an 11-million-mile close encounter on Oct. 20th. Set your alarm for the dark hours before dawn, go outside, and look straight up. You will find Hartley 2 not far from the bright star Capella: sky map. Although the comet is barely visible to the unaided eye, it is easy to find in binoculars and looks great through a backyard telescope.
Last night, Filipe Alves of Portalegre, Portugal, obtained the following long-exposure image using an 8-inch telescope and a KAF-8300 refrigerated CCD camera. It shows the comet's vast green atmosphere and an auburn tail of dust:
Many readers have asked, why is the comet green? Answer: Hartley 2's green color comes from the gases that make up its Jupiter-sized atmosphere. Jets spewing from the comet's nucleus contain cyanogen (CN: a poisonous gas found in many comets) and diatomic carbon (C2). Both substances glow green when illuminated by sunlight in the near-vacuum of space.
NASA scientists say 103P/Hartley 2 is one of the most active comets they've seen, with copious outgassing from jets in the nucleus. Amateur astronomers are encouraged to monitor the action and submit their images here.
http://www.spaceweather.com/submissions/pics/f/Filipe-Alves-103PHartley_1287400018.jpg