Alien Earth Hunter Gets New Lease on Life

NASA's Kepler space telescope, which is looking for Earth-sized planets around other stars, has gotten a mission extension

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Alien Earth Hunter Gets New Lease on Life

NASA has awarded extensions to nine of its astrophysics missions, including Kepler, a space telescope that hunts for planets around other stars. The extension, which could keep Kepler in operation until 2016, should be a boon for the hunt for Earth-like planets around Sun-like stars, which requires observations spanning years. Kepler was just getting started, having launched in March 2009.

The $600 million telescope hunts for exoplanets by staring at a patch of sky containing some 4.5 million Milky Way stars. It uses a 95-megapixel camera to register slight dips in stellar brightness that signal a planet's passage across its host star.

Despite launching with some unexpectedly noisy CCDs, the telescope has proved an efficient planet-finder, turning up 61 confirmed exoplanets and more than 2000 additional candidate worlds. In December, it bagged its first potentially habitable quarry, Kepler 22-b, which sits about 600 light years away and orbits a region around its star that is far enough away—but not too far—to support liquid water. Extending Kepler’s mission, which was due to end in November 2012, will give the telescope time to turn up more such planets.

NASA’s decision followed quickly on the heels of a biennial expert review that recommended life extensions for all the nine astrophysics missions that the committee considered. The review noted that "Kepler is not only a unique source of exoplanet discoveries, but also an organizing and rallying point for exoplanet research. It has enabled remarkable stellar science."

Kepler has certainly spurred additional activity. This year, for example, a new detector called HARPS-N will join the exoplanet hunt and perform follow-up observations of Kepler candidates using Italy’s Telescopio Nazionale Galileo on La Palma, one of the Canary Islands. (IEEE Spectrum featured the Italian telescope in our January round-up of the year in technology.)

The chair of the review, Joel Bregman, who is an astronomer at the University of Michigan at Ann Arbor, told Nature that this year’s review was less of a “financial bloodbath” than the last one, in 2010, because the poor-performing astrophysics missions have already ended or were phased out.

Space Newsnoted that the review committee was sensitive to limited support for new missions in the shadow of the James Webb Space Telescope, Hubble’s successor, which is set to launch in 2018 and expected to cost an estimated $8.8 billion following repeated budget overruns.

Kepler will likely be reviewed again in two years, so an extension through 2016 is not guaranteed. says that Kepler team members have estimated it will cost $20 million a year to keep the mission going.

(Illustration: R. Hurt/NASA/JPL-Caltech)

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