London, Dec 6 (IANS): American astronomers have confirmed the existence of an earth-like planet, dubbed Kepler 22-b, in the "habitable zone" around a star similar to the sun.

The planet lies about 600 light years away and is about 2.4 times the size of earth, and has a temperature of about 22 degrees Celsius, BBC reported. This is the closest confirmed planet to the earth. However, the team does not yet know if Kepler 22-b is made mostly of rock, gas or liquid.

The scientists from NASA's Ames Research Centre said they spotted some 1,094 new candidate planets.

The team had to wait for three passes of the planet before upping its status from "candidate" to "confirmed".

"Fortune smiled upon us with the detection of this planet," said principal investigator William Borucki.

A space telescope was designed to look at a fixed swathe of the night sky, staring intently at about 150,000 stars.

Kepler 22-b was one of 54 candidates reported by the team in February.

More such planets similar to earth are likely to be confirmed in the near future.

Kepler 22-b lies at a distance from its sun about 15 percent less than the distance from the earth to the sun, and its year takes about 290 days.

Its sun puts out about 25 percent less light, keeping the planet at a temperature that would support the existence of liquid water.