NASA has decided to keep its planet-hunting spacecraft running for several more years.
The space agency said Wednesday the Kepler spacecraft will search for alien worlds through fiscal year 2016. The $600 million mission was launched in 2009 to track down other Earths in a faraway patch of the Milky Way galaxy.
The extension came after a team of experts reviewed the project's progress. It is estimated to cost about $18 million a year to operate Kepler in the extended phase.
Kepler has found examples of planets similar in size to Earth orbiting stars outside the solar system.
Scientists are eagerly waiting the discovery of an Earth-size world in the so-called Goldilocks zone _ a place that's not too hot, not too cold, where water might exist in liquid form.