Nasa's Kepler telescope has discovered more than 100 Earth-sized planets orbiting alien stars.

    It has also detected nine small planets within so-called habitable zones, where conditions are favourable for liquid water, and potentially life.

    The finds are contained within a catalogue of 1,284 new planets detected by Kepler , which more than doubles the previous tally. Nasa said it was the biggest single announcement of new exoplanets. Space agency scientists discussed the new findings in a teleconference on Tuesday. 

    Statistical analyses of Kepler's expanding sample of worlds help astronomers understand how common planets like our own might be. Kepler mission scientist at Nasa's Ames Research Center in California, Natalie Batalha said calculations suggested there could be more than 10 billion potentially habitable planets in the Milky Way. 

    Of the telescope's finds to date, the planets Kepler-186f and Kepler-452b are arguably the most Earth-like in terms of properties such as their size, the temperature of their host star and the energy received from their star. The scientists noted that planets in this size range had no known analogues in our Solar System.

Source: QNA