Orbiting a small red star called Gliese 876, the planet is twice the diameter of Earth and maybe seven times as massive.
The star the planet orbits is part of what we see in the Aquarius constellation. Scientists who have found planets outside our solar system noted those finds were much more massive than this recent discovery.
But the size of this discovery makes scientists think it is a rocky planet instead of the gas giants like Jupiter they have found previously. Though it has been called Earth-like, it may instead resemble the planets in our system that are closer to the sun.
“This is the smallest extrasolar planet yet detected and the first of a new class of rocky terrestrial planets,” said Paul Butler of the Carnegie Institution of Washington. “It’s like Earth’s bigger cousin.”
Scientists don’t think this planet supports life. Its surface temperature likely ranges from 400 to 700 degrees Fahrenheit. Two other planets in the same system orbit farther away from the star and are gas giants. But the hunt for more Earth-like planets is only getting started.
“We keep pushing the limits of what we can detect, and we’re getting closer and closer to finding Earths,” said team member Steven Vogt, a professor of astronomy and astrophysics at the University of California, Santa Cruz.
“This planet answers an ancient question,” said team leader Geoffrey Marcy, professor of astronomy at the University of California, Berkeley. “Over 2,000 years ago, the Greek philosophers Aristotle and Epicurus argued about whether there were other Earth-like planets. Now, for the first time, we have evidence for a rocky planet around a normal star.”
David Utter is a staff writer for Murdok covering technology and business. Email him here.
