Signs of planet detected around sun’s nearest neighbor star
Proxima Centauri companion orbits in habitable zone
A WORLD NEXT DOOR Proxima Centauri casts a reddish glow over the surface of Proxima b (illustrated), the closest exoplanet to Earth, while two companion stars, Alpha Centauri A and B, appear as bright pinpricks of light.
M. Kornmesser/ESO
Earth might have a kindred planet orbiting the star next door. A world at least 1.3 times as massive as Earth appears to orbit the closest star to the sun: Proxima Centauri, a dim red orb about 4.2 light-years away.
Dubbed Proxima b, the planet is cozied up to its star, needing just 11.2 days to complete one orbit. But despite the proximity to its star — just 5 percent of the distance from Earth to the sun — Proxima b is potentially habitable. Its temperature is just right for liquid water to flow on its surface, Guillem Anglada-Escudé, an astronomer at Queen Mary University of London, and colleagues report in the August 25 Nature. That makes Proxima b the closest known world outside our solar system where life might exist.
“It’s an incredible discovery — it’s almost a gift,” says David Kipping, an astronomer at the
