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/ESO CZ