Comet Hartley-2 glows softly near the lower right corner of this image snapped October 8 at McDonald Observatory. The comet looks like a faint green blob near a pair of star clusters, the Double Cluster, in Perseus. The comet passed closest to Earth, about 11 million miles (18 million km), on October 20. It is visible through binoculars in the early morning sky. A spacecraft is racing toward the comet and will fly past it on November 4. [Joe Wheelock/McDonald Observatory]