By Ron Cowen
Astronomers report today that they have found an extrasolar planet no more than 11 times Earth’s mass with a diameter about twice that of Earth. The discovery may ultimately provide groundbreaking information about the composition and structure of terrestrial planets beyond the solar system.
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Once the team can refine an estimate of the planet’s mass, “this could be a potentially huge discovery, one that we’ve been waiting for for a long time,” comments theorist Sara Seager of MIT. “I’m excited to see what more the team will find out about this prospective terrestrial planet.”
Classified as a hot superEarth, the planet, too small to be imaged, lies much too close to the blistering heat of its parent star to support life. Located about 450 light-years from Earth, the planet whips about its sunlike star in just 20 hours, has a surface temperature between 1,000 and 1,500 degreesCelsius and might be covered by lava or water vapor.