Two old NASA missions have new lives. The agency’s Deep Impact mission, which 2 years ago fired a projectile into Comet Tempel 1 and imaged the debris from the explosion, will now journey to Comet Boethin.
Deep Impact doesn’t have another bullet in its arsenal but will fly peaceably to Boethin, getting to within 700 kilometers of the object on Dec. 5, 2008, so it can obtain close-up images. This year, en route to the comet, the spacecraft will study several nearby, bright stars known to have massive, orbiting planets. Deep Impact will search for periodic variations in starlight as the planets pass in front of and behind their parent stars. The variations may reveal not only the size and composition of the Jupiter-size planets but also whether they possess rings, moons, or Earth-size companions (SN: 7/14/07, p. 24).
The Stardust mission, which early in 2006 dispatched to Earth material that it collected from the shroud of Comet Wild 2, also has a new assignment. In 2011, the craft will fly past Deep Impact’s old target, Tempel 1. Stardust will look for changes in the comet’s nucleus since the body’s last close passage to the sun.