IT’S the planet we’ve all been waiting for. Earlier this month, rumours swirled that astronomers had discovered an Earth-like planet orbiting the closest star to our own, the aptly named Proxima Centauri. Well, the planet’s real, but don’t pack your interstellar bags yet, because this alien world is probably far from homely.
The planet – Proxima b – was discovered by astronomers who spent years looking for signs of the tiny gravitational tug exerted by a planet on its star, after spotting hints of such disruption in 2013. Proxima Centauri is 4.25 light years from Earth, making it slightly closer than the binary star system of Alpha Centauri, which the Proxima star is thought to loosely orbit.
“We’ve been excited for a long time,” says Guillem Anglada-Escudé of Queen Mary University of London, who led the discovery as part of a project called Pale Red Dot. “We’ve been hunting for this signal and confirmation of the planet for almost four years.”
The team says the planet is likely to be 30 per cent more massive than Earth, although it could be bigger than that. It orbits the star at a distance of 7.3 million kilometres – less than 5 per cent of the distance between Earth and the sun – making its year last just 11.2 Earth days.
You might think such a tight orbit would scorch the surface of the planet. But Proxima Centauri is a small, red dwarf star and shines much less fiercely than the sun. Standing on the surface of the planet, you’d see the star as a dull red orb, about three times as large as the sun appears from Earth. As a result, the planet sits in its star’s habitable zone, and its surface temperature may be right for it to host liquid water.
The planet is rocky, of a similar mass to Earth, and temperate – all conditions that are promising for life. But Proxima b isn’t a second Earth. (Al Jazeera)