Copyright 2007 John Hodge
The extraordinary comet 17P/Holmes from Monday, October 29th. The previous week, this comet had been invisible...but burst forth brightening nearly a million times in less than 24 hours. The cause is unknown, but is theorized to have been caused by a collapse of hollow areas in the icy nucleus (seen here as a bright speck just to the upper right of center) causing a huge amount of ice to immediately sublimate into a gas cloud. The major portion of the cloud appears yellowish in binoculars and can be seen here to posses a dark circumferential band which might be an indicator of a slowing of the outgassing at some point.