Meet Proxima b: the insanely close Earth-like planet that could actually support life

Earthlings, say hello to your neighbors. 

Astronomers at the European Southern Observatory have discovered what could be the closest possible planet for life outside the solar system. A mere 4.2 light-years—or 25 trillion miles—away from Earth, Proxima b is extremely close in cosmic terms. The rocky planet is slightly larger than our own and orbits within what scientists call the “habitable zone,” meaning it has a temperature suitable for liquid water. And where there’s water, there may be life.

ESO is calling the discovery a “milestone” and says a paper describing the findings will be published in the journal Nature later this week. 

So why did they give such an important discovery a name that sounds like an anti-itch cream? Because Proxima b orbits Proxima Centauri, a red dwarf and the closest star to our own sun. Things move pretty fast there: Proxima b orbits its star every 11 days.  

An artist’s rendition of Proxima b orbiting the red dwarf star Proxima Centauri.

 Credit: M. Kornmesser/ESOCZ