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. NASA astronomers announced its existence on April 17, 2014. (NASA)
PASADENA, California - Astronomers have found the first Earth-size planet orbiting its star in the so-called "habitable zone" - that distance from the star where liquid water might pool on the surface.
The planet, Kepler-186f, confirms that Earth-size planets do exist in the habitable zones of other stars than our sun, NASA said today. Astronomers called the planet, which they believe is rocky, "reminiscent of Earth."
"The discovery of Kepler-186f is a significant step toward finding worlds like our planet Earth," said Paul Hertz, NASA's Astrophysics Division director, at NASA headquarters in Washington.
The planet is in the Kepler-186 system about 500 light-years from Earth in the constellation Cygnus. The system has four other planets orbiting a star half the size of the sun.
The Earth-like planet orbits its star once every 130 days and gets one-third the energy from that star that Earth gets from the sun. Astronomers said that on the surface, the light at noon would be about as bright as late afternoon on Earth.
The next step in the search for life is looking for "true Earth-twins," NASA said, not just Earth-size planets.