For the first time since its launch in 2009, NASA’s Kepler spacecraft has confirmed the existence of a planet outside our solar system located firmly in a habitable-zone orbit around its sun, NASA announced on Monday.
The habitable zone is an area around a star in which the temperature on a planet’s surface is just right for water, which is essential to life on Earth, to exist as a liquid. It’s thought that if life exists outside our solar system, the habitable zone represents the best chance to find such life.
The average surface temperature of the planet, dubbed Kepler-22b, might be about 72 degrees, according to researchers, making it likely that if water does exist on the planet, it’s in the form of liquid.
"This is a major milestone on the road to finding Earth's twin," said Douglas Hudgins, Kepler program scientist at NASA headquarters in Washington.
Kepler-22b is about 600 light years from Earth, is about two-and-a-half times the diameter of our planet, and orbits slightly closer to its sun than we do to ours. So far, Kepler has confirmed the existence of 28 planets outside the solar system, and found evidence of more than 2,300 others.
Below are artists' conceptions, photos, and video of this and some of Kepler's other findings.