Kepler - 186f, the first Earth - size Planet in the Habitable Zone - Kepler...

Kepler - 186f, the first Earth - size Planet in the Habitable Zone - Kepler - 186f is the first Earth-sized planet in the habitable zone of its star to be discovered. It orbits Kepler - 186, a red dwarf located in the constellation of Swan, between 490 and 500 years of light from the Earth. The artist's concept depicts Kepler - 186f, the first validated Earth - size planet to orbit a distant star in the habitable zone - - a range of distance from a star where liquid water might pool on the planet's surface. The discovery of Kepler - 186f confirms that Earth - size planets exist in the habitable zones of other stars and signals a significant step closer to finding a world similar to Earth. The size of Kepler - 186f is known to be less than ten percent larger than Earth, but its mass, composition and density are not known. Previous research suggests that a planet the size of Kepler - 186f is likely to be rocky. Prior to this discovery, the “” record holder”” for the most “” Earth - like”” planet went to Kepler - 62f, which is 40 percent larger than the size of Earth and orbits in its star's habitable zone. Kepler - 186f orbits its star once every 130 days and receives one - third the energy that Earth does from the sun, placing it near the outer edge of the habitable zone. If you could stand on the surface of Kepler - 186f, the brightness of its star at high noon would appear as bright as our sun is about an hour before sunset on Earth. Kepler - 186f resides in the Kepler - 186 system about 500 light - years from Earth in the constellation Cygnus. The system is also home to four inner planets, seen lined up in orbit around a host star that is half the size and mass of the sun. The artistic concept of Kepler - 186f is the result of scientists and artists collaborating to imagine the appearance of these distant worlds