Yesterday researchers from the NASA’s Kepler Space Telescope announced the discovery of 833 more candidate planets, 104 of which have the potential to harbor life. Included in that 104 in their respective Goldilocks Zones are 10 that are roughly the same size as Earth. As of this announcement, the total number of exoplanets discovered by Kepler since its launch in 2009 is now at 3,538. Its mission is to explore exoplanets and discover which ones are similar in size to Earth and are capable of supporting life. The announcement is coming from Kepler Science Conference, which is hosting over 400 scientists representing 30 countries.
According to William Borucki, the principal investigator for Kepler’s science mission, these discoveries “[open] a new era of exploration of our galaxy.” The first potentially habitable planet was announced two years ago, and since astronomers now believe there that most stars in the galaxy have at least one planet there is the possibility of many more potentially life-harboring discoveries to come.
This spring, Kepler's mission was changed when two out of the four wheels used to point the telescope toward its targets broke, and NASA scientists were unable to repair them. Kepler completed its initial mission in 2012, and is currently completing an extended mission. Despite this, there is still a full year’s worth of data that has not been processed yet as Kepler monitored 150,000 stars and recorded data once every half hour for those four operational years.
One analysis of Kepler’s data suggests that around 20% of sun-like stars have an Earth-like planet. So far, there have not been any reports of any such planet that completely mirrors Earth in terms of habitability and revolution length around a star like ours, but astronomers will continue to search.