It is the first planet with a radius similar to Earth’s to be discovered in the habitable zone of another star.
Distance to Earth – 557.7 light years
Kepler-186f (also known by its Kepler Object of Interest designation KOI-571.05) is an exoplanet orbiting the red dwarf Kepler-186, about 550 light-years (171 parsecs, or nearly 5.298×1015 km) from the Earth.
NASA’s Kepler spacecraft detected it using the transit method, along with four additional planets orbiting much closer to the star (all modestly larger than Earth).
Analysis of three years of data was required to find its signal. The results were presented initially at a conference on 19 March 2014 and some details were reported in the media at the time. The public announcement was on 17 April 2014, followed by publication in Science.
Kepler-186f is 10% bigger and occupies its star’s ‘habitable zone’ where temperatures would allow liquid surface water.