NASA has sent the Deep Impact comet-hunter in a new direction, after realizing that a second comet researchers had hoped to study had seemingly vanished.
Deep Impact is one of these NASA missions that keep on giving, having already completed its original task of launching a small probe into collision with the Tempel 1 comet in 2005. But the main spacecraft remains operational, with instruments to be used, and so scientists have decided to take on another comet.
Initially they'd hoped to find and study a second comet named Boethin, trying to determine if odd features they observed on Tempel 1 are in fact common. But Boethin now seems to have vanished, and researchers think it may have broken up.
Instead, they're now directing Deep Impact (now called EPOXI, or Extrasolar Planet Observation and Deep Impact Extended Investigation) towards a comet named Hartley 2, which shares features with the vanished Boethin, such as having a small, active nuclei. Following three Earth flybys to help set course, the craft will reach the comet in 2010.
"When comet Boethin could not be located, we went to our backup, which is every bit as interesting but about two years farther down the road,"
said Tom Duxbury, EPOXI project manager at NASA's Jet Propulsion
Laboratory.
But that time won't be wasted. Late next month, researchers will point the EPOXI telescopes toward several previously discovered solar systems that lie around distant stars, looking for new planets, and studying the characteristics of already-observed planets.
It will also look back at Earth using the same techniques, providing a comparison basis against which to analyze its extrasolar observations.
The extended, retargeted mission is costing NASA $40 million, a low price tag allowed by re-use of the existing spacecraft.
NASA Sends Spacecraft on Mission to Comet Hartley 2 [NASA press release]
(Image: The Tempel 1 comet originally studied by Deep Impact. The large arrow points to the impact probe's point of collision. Arrows A and B are large, smooth areas, while the small arrows appear to be cliffs. Credit:
NASA/JPL/UMd)
