NASA finds 1st habitable zone planet
An artistic conception illustrating Kepler-22b, a planet known to comfortably circling in the habitable zone of a sun-like star
NASA has confirmed the discovery of Kepler-22b, the first planet in the "habitable zone," where liquid water could exist on a planet's surface.
The Kepler spacecraft discovered Kepler-22b in the habitable zone, 600 light-years away from Earth, NASA said on Monday.
The discovery of Kepler-22b brings scientists one step closer to finding a planet that could possibly harbor life.
"This is a major milestone on the road to finding Earth's twin," Kepler program scientist Douglas Hudgins said in a statement.
"Kepler's results continue to demonstrate the importance of NASA's science missions, which aim to answer some of the biggest questions about our place in the universe."
Kepler-22b has several Earth-like characteristics. Its temperature is around 72 degrees Fahrenheit and its radius is 2.4 times Earth's. The planet completely orbits its star, which is similar to our sun, every 290 days, just 75 days shy of an Earth year.
NASA says scientists do not yet know if Kepler-22b has a predominantly rocky, gaseous or liquid composition, but its discovery is a step closer to finding Earth-like planets.
Of the 54 habitable zone planet candidates reported in February 2011, Kepler-22b is the first to be confirmed.