Around the time Earth formed, a slightly larger world coalesced by a much different star. Our sun was a steady, bright-yellow dot in its neighbor’s night
sky, but the two stars — and likely their planets — evolved along much different paths. The other star was a red dwarf, dim and cool and prone to violent
outbursts. It rained harsh radiation onto its world’s surface, and lit it with the soft orange hue of a perpetual sunset.
That ruddy star was Proxima Centauri, our sun’s nearest stellar neighbor, just 4.2 light-years away. The star’s violent emissions long obscured the planet
orbiting it. Thanks to a monthslong observing campaign, however, astronomers deduced and finally confirmed the planet’s existence in August. Dubbed Proxima
b, it sits smack in the middle of its star’s habitable zone, where liquid surface water — and thus possibly life — could exist.