No one will ever find a closer exoplanet—now the race is on to see if there is life on its surface.
One hundred and one years ago this October, a Scottish astronomer named Robert Innes pointed a camera at a grouping of stars near the Southern Cross, the defining feature of the night skies above his adopted Johannesburg. He was looking for a small companion to Alpha Centauri, our closest neighboring star system.
Hunched over glass photographic plates, Innes teased out a signal. Across five years of images, a small, faint star moved, wiggling on the sky. It shifted just as much as Alpha Centauri, suggesting its fate was intertwined with that binary system. But this small star was closer to the sun than Alpha. Innes suggested calling it Proxima Centauri, using the Latin word for “nearest.”
The dim red star soon entered the collective imagination, inspiring dreams of interstellar travel. Gravity has linked the star to the Alpha Centauri system, but our culture of science and storytelling has linked it to the solar system. Today, that link will grow stronger, when an international team of astronomers announces that this nearest of stars also hosts the closest exoplanet, one that might look a whole lot like Earth.