WASHINGTON, Sept 1: A new class of planets has been found orbiting stars besides our sun, in a possible giant leap forward in the search for Earth-like planets that might harbour life, scientists said on Tuesday.

Aa European team of astronomers announced last week the discovery outside our solar system of a planet some 14 times Earth's mass, a so-called super Earth. "We can't quite see the Earth-like planets yet, but we are seeing their big brothers, and hopefully we will be bearing down on these small-mass planets soon," said Paul Butler of the Carnegie Institution of Washington, the co-discoverer of one of the new planets.

The two new planets are about 15 to 20 times more massive than Earth - approximately the mass of Neptune - and have diameters about two or three times the size of our home planet, astronomers said at a news conference at NASA headquarters.

That makes these new bodies different from most of the other so-called exoplanets found in the last decade outside our solar system. These other planets, more than 100 of them, are generally about the mass of Jupiter - about 318 times Earth's mass - and are thought to be balls of gas, completely inhospitable to life as Earthlings know it.

But the newly discovered planets indicate that planetary systems around other stars could have the same assortment of planets as in our solar system: big gassy ones like Jupiter, middle-weight rocky ones like Neptune and just possibly, relatively small rocks like Earth.

If scientists find an Earth-mass planet, they could then search for one located just the right distance from its star, making it temperate enough to allow for the presence of water on its surface, considered a requirement for life.

No one has ever seen an extrasolar planet. Most have been detected by looking for a characteristic wobble in a distant star, a sign that a planet's gravity is tugging on the star in a specific way. -Reuters