Possibly Habitable Exoplanet Discovered Just 4.24 Light Years Away

It’s one of the closest exoplanets we’ve found to Earth—both literally and figuratively.

The long-rumored, newly unveiled Proxima b zips around its star, the red dwarf Proxima Centauri, in just 11.2 days. The small star casts a dim reddish light, which means that despite its close orbit, Proxima b sits right in the habitable zone where liquid water could exist. Its just 1.3 times bigger than Earth and is relatively close—just 4.24 light years away.

An artist's impression of what Proxima b might look like.

Astronomer Guillem Anglada-Escudé, a lecturer at Queen Mary University in London, and his team pored over data collected between 2000 and 2014 by two European Southern Observatory telescopes, finding faint evidence of Proxima b. They then confirmed their findings earlier this year through a series of observations specifically intended to detect the exoplanet.

Researchers still don’t know what Proxima b’s atmosphere consists of—if it even has one—or whether liquid water does, in fact, exist on its surface. But the discovery is already raising the possibility of manned or robotic missions to the remote world. Here’s Nadia Drake, reporting for National Geographic:

The Alpha Centauri system, long a wonderland for science fiction authors, is often considered a destination for humanity’s first leap into interstellar space—as well as a potential haven for future civilizations fleeing the inevitable destruction of Earth as we know it.

“A habitable, rocky planet around Proxima would be the most natural location to where our civilization could aspire to move after the sun will die, five billion years from now,” says Avi Loeb of the Harvard-Smithsonian Center for Astrophysics, who is an advisor to the Breakthrough Starshot project.

This is the sort of world that the team at Breakthrough Starshot has envisioned visiting. Announced earlier this year, the project envisions sending a light sail spacecraft to the Alpha Centauri system at 20% the speed of light.

At that rate, it would still take the ship about 20 years to reach the system and another 4.24 years to send word back of success or failure. Breakthrough Starshot hopes to launch about 20 years after funding is secured.