An Earth-size planet that could boast water, even an ocean, has been found circling the star nearest our sun, hinting that the conditions for life could exist next door.
The find, reported in a study published Wednesday in Nature, has scientists excited.
“An absolutely amazing discovery,” says Victoria Meadows of the University of Washington. “This will be the most accessible, closest planet in the habitable zone to our solar system.”
“The excitement is that it’s around the closest star to our sun,” says Rory Barnes, also of the University of Washington, adding that it’s “exciting, too, to realize perhaps the next star over has a planet with life on it.”
Announced after a search by astronomers from around the world, the new planet circles a small star called Proxima Centauri. That star, though invisible to the naked eye, is only 4.2 light-years — about 25 trillion miles — from Earth, making it our nearest stellar neighbor.
The specs of the new planet, called Proxima b, sound much like Earth’s. It is 1.3 times the mass of the Earth or bigger. It is probably rocky, like Earth, and not a Jupiter-like ball of gas. And it’s just the right distance from its star that it would be warm enough for liquid water to pool on the surface, assuming the planet has an atmosphere. Picking out the planet has taken some of the most powerful telescopes in the scientific arsenal. The first signals of a world orbiting Proxima Centauri were recorded more than a decade ago, and more such signals have continued to trickle in – but never enough to be convincing. So astronomers recruited multiple telescopes to stare at the star earlier this year.
To determine whether organisms thrive on Proxima b, scientists will need to take a picture of the planet itself. Analysis could reveal molecules that would be telltale signs of life.
No existing instrument could snap such pictures. But such technology is under design, and the new discovery will likely galvanize construction of observatories that could take a portrait of this new world. The planet is even close enough that perhaps someday robots could reach it.
A space mission to reach exoplanets won’t be ready until the “coming centuries,” says David Armstrong of Britain’s University of Warwick. “But the first one we’ll send it to will be this.”

Source: usatoday.com