Comet Hartley Passes a Double Star Cluster

Explanation: Most star clusters are singularly impressive. Open clusters NGC 869 and NGC 884, however, are doubly impressive. Also known as “h and chi Persei”, this unusual double cluster , shown above, is bright enough to be seen from a dark location without even binoculars . Although their discovery surely predates written history , the Greek astronomer Hipparchus notably cataloged the double cluster . The clusters are over 7,000 light years distant toward the constellation of Perseus , but are separated by only hundreds of light years. Captured earlier this month, the bright comet 103P/Hartley , informally called Comet Hartley 2, passed well in front but only a few degrees away from the famous double cluster. Comet Hartley 2 , visible on the right, is now fading but still discernable to northern observers with binoculars. No binoculars are needed, of course, if you go right up to the comet's nucleus , as is the plan for NASA's EPOXI spacecraft on November 4.