Kepler's hunt for earth-like planets is over, but its data lives on
Broken planet-hunter has collected enough data to keep scientists busy for years to come
Nasa says its celebrated planet-hunting Kepler spacecraft, which broke down in May when a wheel that controls where it points failed, cannot be fixed and will never again search for planets around other stars.
The disappointing news brings to an end, for now, one phase of the most romantic of space dreams, the search for other earths among the exoplanets of the Milky Way. Nasa has already asked astronomers for ideas on how to use the hobbled spacecraft, whose telescope remains in perfect shape.
Even as they mourned the end of Kepler, astronomers said its legacy would continue as they worked their way through a trove of data the spacecraft has gathered.
At last count, Kepler had discovered 3,548 possible planets, and 135 of them - some smaller than the earth - have been validated by other observations, including earth-bound telescopes. But hundreds or thousands more are in the pipeline, said William Borucki of Nasa's Ames Research Laboratory in Mountain View, California, Kepler's originator and principal investigator.
"The most exciting discoveries are going to come in the next few years as we search through this data," Borucki said. "In the next few years we're going to be able to answer the questions that inspired Kepler: are earth-like planets common or rare in the galaxy?"