On April 17, 2014, NASA announced the discovery of Kepler-186f, the first Earth-sized exoplanet to be found within the habitable zone of its host star. Kepler-186f is orbiting the red dwarf Kepler-186, about 582 light years from Earth. The star hosts four other planets. However, Kepler-186 b, c, d, and e are not habitable as they are very close to their star. They are considered too hot to have liquid water and to host life. Kepler-186f orbits its star compared to what Earth gets from the Sun. The discovery was seen as s significant steps towards finding worlds like planet Earth.
The four companion planets, Kepler-186b, Kepler-186c, Kepler-186d, and Kepler-186e, whiz around their sun every four, seven, 13, and 22 days, respectively, making them too hot for life as we know it. These four inner planets all measure less than 1.5 times the size of Earth.
The next steps in the search for distant life include looking for true Earth-twins — Earth-size planets orbiting within the habitable zone of a sun-like star — and measuring their chemical compositions. The Kepler Space Telescope, which simultaneously and continuously measured the brightness of more than 150,000 stars, is NASA’s first mission capable of detecting Earth-size planets around stars like our sun.
Picture Credit : Google