Scientists Discover “Earth-Like” Planet Within Reachable Distance
We’ve talked a little bit about exoplanets and “a new Earth” before, but the biggest problem with them has always been distance. One of the top candidates for another Earth-like planet (one that could host life) was Kepler-186f. Unfortunately it’s about 500 lightyears away. But now there’s a newly discovered planet, and it’s much closer and more hopeful than Kepler-186f ever was. Ladies and gentlemen, this is Proxima b.
A new Nature study revealed the planet residing in the Alpha Centauri triple star system. Proxima b orbits the red dwarf Proxima Centauri, which is the closest star to Sol (the Sun). It was discovered after years of analysis of the tiny movements of the host star, which is a response to the gravitational pull of the planet itself. These wobbles give astronomers ideas of the planet’s mass, about 1.3 times Earth’s mass.
Interestingly, it is tidally locked, which means one side of the planet is facing the star and the other is in perpetual darkness. Based on its star system, Proxima b is about 5 billion years old. It’s reported to be terrestrial, meaning it has a rocky surface and its temperature indicates there is a possibility for liquid water. As we know, water equals life and at only 4 light years away, Proxima b is the nearest possible home for life outside our Solar System.
However, it is still unknown if Proxima b has an atmosphere. Proxima Centauri is about 88% less massive than Sol, and 99.85% less luminous, meaning if Proxima b was at an Earth-Sun distance, it would be a cold, dead world. But it’s actually at about 5% of the Earth-Sun distance. At this proximity, Proxima b receives about 100 times more high energy X rays than Earth does. These could blow away a thin atmosphere and prevent life from evolving. It all really depends on the mysterious past of the planet.
“It depends on the initial conditions. Either this planet formed dry, or it formed far away and brought a lot of water with it from beyond the ice line,” lead author Dr Guillem Anglada-Escudé said. “Perhaps it started dry and comets rained every once in a while down on it and brought more water with it. There are viable models that lead to an Earth-like planet today.”
So is Proxima b the next Earth? Well, it could be. At the moment all we know is it checks most of the boxes for life, bar that atmosphere problem. We’ll have to wait for astronomers to explore it in more depth, or until we can send some sort of probe there to explore for us. Either way, exciting space times lie ahead!