A potentially habitable alien planet — one that scientists say is the best candidate yet to harbor water, and possibly even life, on its surface — has been found around a nearby star.
The planet, dubbed GJ 667Cc, orbits a red dwarf star 22 light-years from Earth, in the constellation Scorpio. A binary pair of orange dwarf stars are part of the same system.
The new planet has a mass 4.5 times that of Earth and orbits its host star every 28 days.
The red dwarf is relatively dim, so the planet receives slightly less light from its star than Earth does from the sun. But most of the star's light is infrared, so the planet should absorb more of its incoming energy than Earth does from sunlight.
That means if the planet has a rocky surface—which is predicted for planets less than ten times Earth's mass—and an atmosphere, it could support liquid water and maybe life, said co-discoverer Guillem Anglada-Escudé, who conducted the work while at the Carnegie Institution for Science in Washington, D.C.
"If it has an atmosphere, it's probably reddish all the time, because the star is really red," Anglada-Escudé said. "It would be like being evening all the time."
For any hypothetical observers on the surface, the binary stars in the distance would be "very prominent in the sky, and it would be an exotic thing."
New Super-Earth May Be First of Many: Study co-author Anglada-Escudé, who is now a postdoc at the University of Gottingen in Germany, would like to eventually confirm that GJ 667Cc is in fact a potentially habitable super-Earth.
That would require a transit observation, when astronomers measure the dimming of the host star's light as the planet passes in front of the star, as seen from Earth.
Transit data can help astronomers determine a planet's density—and thus its composition—and possibly observe its atmospheric characteristics.
