New Mini-Planet Found; Shot In Arm for ET Search

A newfound extrasolar planet is the smallest yet discovered orbiting a star smaller than our sun, astronomers announced today.

The find may increase the chances of finding life-supporting "exoplanets," they added.

The planet, dubbed MOA-2007-BLG-192Lb, is just three times more massive than Earth and orbits what is most likely a brown dwarf—a "failed" star that is so small its core may not be massive enough to maintain nuclear reactions for very long.

The planet is 3,000 light-years from Earth and has a close-in orbit similar to Venus's. But because the newfound body's parent is so much cooler than our sun, MOA-2007-BLG-192Lb is most likely to be even colder than Pluto.

Even so—and despite almost no solar heating—there's a slim chance that the planet could maintain a habitable temperature if the atmosphere is as thick with molecular hydrogen as researchers think it could be, according to study leader David Bennett.