Closest Neighbor

Proxima Centauri b is the closest planet outside our own solar system. So it’s natural to wonder whether it might support life. As with many other exoplanets, the answer is maybe. It has some big plusses, but perhaps some even bigger minuses.

The planet orbits Proxima Centauri, the closest star to our own – a bit more than four light-years away. It’s so faint, though, that it’s not visible without a telescope.

Proxima b is one of three possible planets orbiting the star. But it’s the only one in the “habitable zone” – the region around the star that’s thought to be comfortable for life. And the planet is about the same size and mass as Earth. Those are the plusses.

The minuses have to do with the star — a red dwarf. It’s much smaller, cooler, and less massive than the Sun. And most of the time, it produces much less than one percent as much energy as the Sun does.

Sometimes, though, Proxima flares up. It produces explosions of energy and particles that are a thousand times stronger than anything yet seen from the Sun. Proxima b is only about four-and-a-half million miles from the star – just five percent of the distance from Earth to the Sun. So the flares blast the planet with X-rays and charged particles. That could erode the planet’s atmosphere – if it has one – and zap any life on the surface.

So the odds seem to be against finding life on this nearby neighbor – at least for now.
 

Script by Damond Benningfield