Planet found at solar system’s closest neighbor

After scanning the vast reaches of the cosmos for Earth-like planets where life might exist, astronomers have found one right next door.

A planet that is rocky like Earth and only slightly more massive has been discovered orbiting Proxima Centauri, the nearest star to our solar system, scientists reported August 24.

Dubbed Proxima b, the planet could be reachable by tiny, unmanned space probes before the end of the century, in time for some people alive today to witness it.

It might be in the not-too-hot, not-too-cold “Goldilocks Zone” where liquid water — a key to life — is possible. And it is a mere 4.22 light-years from Earth, or about 40 trillion kilometers.

Artist's drawing of planet orbiting star (European Southern Observatory/ M. Kornmesser)
Seen in an artist’s conception, the planet Proxima b (right) orbits our solar system’s closest neighbor, called Proxima Centauri. (European Southern Observatory/M. Kornmesser)

While it could be like Earth in the important features, it would probably still look very alien. As the planet orbits its star at one-twentieth of the distance between Earth and the sun, the sky would be an incredible orange, with no blue, making it look like a perpetual sunset. The planet circles its star so quickly that its year is about 11 days.

Time for a Starshot?

Earlier this year, scientists and business leaders including Stephen Hawking and Mark Zuckerberg announced Breakthrough Starshot, a project to send out hundreds of light-powered space probes that would travel at one-fifth the speed of light and send pictures back to Earth.

Proxima b should be on the itinerary, said Pete Worden, the project’s executive director and a former top NASA official. Starshot is planning to launch by 2060, he said.

Guillem Anglada Escude, an astrophysicist at Queen Mary University of London and lead author of a study on the planet’s discovery, is excited.

“We hit the jackpot here.”