Scientists discover Earthlike planet

Scientists using a technique derived from Albert Einstein’s theories said Wednesday they have detected the most Earthlike planet ever discovered outside the solar system – an icy, rocky world 51/2 times the size of Earth orbiting a star 28,000 light years away.

The new planet, given the identifier OGLE-2005-BLG-390Lb, was discovered last summer using telescopes researchers spread throughout the world. The scientists said the discovery suggested Earth-sized planets are quite common in the universe.

“We’re opening a new window,” said University of Notre Dame astrophysicist David Bennett in a Webcast news conference hosted by the National Science Foundation.

In the last decade, scientists have found more than 160 planets circling stars outside our solar system.

Most of the discoveries were made by measuring the “wobble” in a star’s motion caused by the gravitational pull of its planet. The current discovery, reported in today’s issue of the journal Nature, took advantage of a relatively new technique called gravitational microlensing, based on Einstein’s precept that light from a distant star is bent by the gravitational pull of intervening stars on its way toward Earth.

Analysis of the data showed a planet in an orbit 242 million miles from its star – the equivalent of the solar system’s asteroid belt. But since the star was only about one-fifth the size of its sun, the planet probably has a temperature of minus 364 degrees Fahrenheit, a ball of ice and rock more like Pluto than Earth.