An Earth-like planet is orbiting the sun closest to ours, scientists announced Wednesday.
The planet, called "Proxima b," orbits a star called "Proxima Centauri" and has a temperature that would allow liquid water to exist there, according to a statement released Wednesday by the European Southern Observatory. That means the world is possibly habitable, but scientists don't know yet whether there's anything living there.
"This rocky world is a little more massive than the Earth and is the closest exoplanet to us ― and it may also be the closest possible abode for life outside the solar system," ESO said.
Proxima Centauri, a red dwarf star, lies just 4.25 light-years away from Earth. While that's pretty far away by astronomical distances, it's just a drop in the cosmic bucket. Other Earth-like exoplanets that have been discovered are much farther away from Earth, which makes the revelation of Proxima b more exciting.
Earlier this year, researchers in Chile looked at Proxima Centauri using the High Accuracy Radial velocity Planet Searcher, or HARPS, a high-resolution instrument that specializes in the search for extrasolar planets. They were searching for a wobble in the star that would indicate the gravitational tug of a potential orbiting planet.
What they found amazed them.
"The first hints of a possible planet were spotted back in 2013, but the detection was not convincing," Guillem Anglada-Escude of Queen Mary University in London, who led the Chile team, said in the ESO statement. This year, the team checked every day during the 60 nights of their scans of Proxima Centauri. "The first 10 were promising, the first 20 were consistent with expectations, and at 30 days, the result was pretty much definitive, so we started drafting the paper!" he said.
The researchers will publish their scientific paper detailing the astronomical finding on Aug. 25 in the journal Nature.
The following video is an imagined fly-through of the Proxima Centauri system:
Video Credit: PHL @ UPR Arecibo, ESO Music by Lyford Rome
Proxima b is about 1.3 times bigger than Earth and orbits its parent sun approximately every 11 days. It's a lot closer to its star than we are ― just 5 percent of our Earth-Sun distance, according to ESO.
Astronomers say that Proxima b is orbiting in a habitable zone, meaning the planet's surface temperature could promote the presence of liquid water. But that doesn't necessarily mean there's any life there. Radiation from the red dwarf star could cause a much different climate on Proxima b than we have on Earth.
The discovery and confirmation of the planet now begins a more extensive exploration of our very close ― cosmically speaking ― neighbor. And that means the planet will become a major target in the search for life elsewhere.
"Many exoplanets have been found and many more will be found, but searching for the closest potential Earth-analogue and succeeding has been the experience of a lifetime for all of us," said Anglada-Escude.
"Many people's stories and efforts have converged on this discovery. The result is also a tribute to all of them. The search for life on Proxima b comes next."