En route to comet Hartley 2



NASA has given the go-ahead for the Deep Impact spacecraft to fly to comet Hartley 2 after the original target, comet Boethin, could not be found despite extensive searching. The spacecraft, which successfully guided an impactor into comet Tempel 1 in July 2005, will fly by comet Hartley 2 on 11 October 2010 as part of a two-part extended mission known as EPOXI. During the first part of the mission—Extrasolar Planet Observation and Characterization—a large telescope on the spacecraft will observe and study several previously discovered extrasolar planetary systems. During the second part of the mission—the Deep Impact Extended Investigation—the spacecraft will fly to within 1000 kilometers of the 0.8-kilometer-wide comet and study it with two telescopes and an infrared spectrometer.