Heading for a Rendezvous

Comet Hartley 2 streaks across the sky in this recent image from an orbiting infrared telescope. The comet's dust trail stretches almost two million miles behind it. The comet will pass just 11 million miles from Earth on October 28. One week later, a spacecraft will fly within about 400 miles of the comet's icy surface. [NASA/JPL/UCLA]