Proxima b: Scientists just discovered the closest Earth-like planet ever

ESO/M. Kornmesser

It seems the rumors about a new exoplanet in our backyard are true. Scientists have discovered a small, rocky exoplanet orbiting around our closest star, Proxima Centauri. 

The planet, named Proxima b, is about 1.3 times the size of Earth. Proxima Centauri is only about four light-years away from us, which means Proxima b is the closest Earth-like exoplanet we've ever discovered. Scientists think it's warm enough for liquid water to exist on its surface. 

The research is published in the journal Nature.

"The search for life on Proxima b comes next," lead author Guillem Anglada-Escudé said in a statement.

Illustration of Proxima Centauri and Proxima b  ESO/YouTube

About the planet

Earth sits about 150 million kilometers from the sun, but Proxima b orbits just 7.5 million kilometers away from Proxima Centauri. That means the planet is likely subjected to intense radiation, and scientists can't tell if it has a protective magnetic field or not. 

Proxima b orbits much closer to its star than Mercury does to our sun.Source: ESO/M. Kornmesser/G. Coleman
Proxima b orbits much closer to its star than Mercury does to our sun.  ESO/M. Kornmesser/G. Coleman

How scientists found it

Proxima Centauri is an incredibly faint star. Scientists used a variety of telescopes around the world to study it over the last 16 years. They noticed that the star would approach us at about 3 miles per hour for a while, and then recede from us at the same pace. 

The pattern would repeat every 11.2 days. After careful analysis of the pattern, the team concluded that a planet must be causing the wobbling effect.

"Once we had established that the wobble wasn't caused by star spots, we knew that that there must be a planet orbiting within a zone where water could exist, which is really exciting," co-author John Barnes said. "If further research concludes that the conditions of its atmosphere are suitable to support life, this is arguably one of the most important scientific discoveries we will ever make."

Why it matters

This is the closest exoplanet we've ever found that has the potential to support life. 

Billionaire Yuri Milner and physicist Stephen Hawking recently launched a research program designed to figure out a way to send a probe to Proxima Centauri. 

We might be exploring an Earth-like exoplanet sooner than anyone thought.