What if Earth became uninhabitable tomorrow?
That sounds impossible… until you realize the universe is already full of planets that might be able to support life. Not perfect planets. Not safe planets. Just planets that are maybe, barely, terrifyingly possible.
The first one is Proxima Centauri b. It is the closest known exoplanet to us, sitting just 4.2 light years away. In cosmic terms, that is basically next door. It also sits in the habitable zone, which means liquid water could exist ther