NASA retired its planet-hunter, Kepler, as it has run out of fuel. In nine years, the space telescope has helped discover over 2,600 planets.
NASA has decided to retire Kepler within its current, safe orbit, away from earth. Kepler was launched on march 6, 2009 and was originally positioned to stare continuously at 150,000 stars in one star-studded patch of the sky.
It became NASA's first mission to detect earth-size planets that could potentially be inhabited by humans. Kepler's most recent discovery concludes that 20-50% of the stars visible at night might have rocky planets similar to earth's size and located within the habitable zone of their parent stars.
That means they're located at distances where liquid water might pool on the planet surface. NASA says scientists are expected to spend a decade or more in search of new discoveries from the data Kepler provided.