So, you’ve probably seen tons and tons of new stories about Earth-like planets around nearby stars. That’s mostly because over the past few years we’ve launched powerful new telescopes like Kepler that are just sharp enough to find the tiny (in galactic terms, anyway) planets.
We’ll have to wait for the launch of James Webb next year to know for sure, but as scientists refine their models and hone their studies of these exo-Earths, we’re a bit more confident that they might be able to sustain life.
Proxima B, an Earth-sized planet orbiting Proxima Centauri, our closest stellar neighbor, has been thought to be uninhabitable without a lot of extra help. Early models suggested that it just wouldn’t have a stable atmosphere. Pb, as I’ve just now decided to call it, circles its star much closer than we do with the Sun. Scientists suspect that that means the planet is tidally locked with its parent star.
That could be disastrous for any atmosphere it may have once had. Gasses could freeze out on the night side, for example, causing the planet’s air to slowly fall as super-cold snow until it was all gone. Alternatively, proximity to the star could cause solar winds to blow the atmosphere off into space.
Eager for answers, teams of researchers have applied some more robust weather and atmospheric models based our knowledge of Earth’s atmosphere to the planet, and initial results are… pretty positive. Obviously, they won’t be accurate, and we’re missing loads of additional data we’d need to get optimal predictions, but the paper, published in Astronomy and Astrophysics suggests that we’d expect it to still have a stable atmosphere in several possible scenarios.
Scientists ran simulations with both a tidally locked and slowly orbiting planet, and both featured climates that could sustain liquid water — one of the most important ingredients, we suspect, for life. This is good news for anyone eager to bail on Earth and set up shop somewhere a bit less… chaotic.
The study isn’t without qualifications. There’s far from enough data to be sure that Proxima B definitely has an atmosphere in the first place. All we can say right now is that if it did, that atmosphere could very well be stable and the climate might foster liquid surface water.
The good news, though, is that we probably won’t have to wait long to find out for sure. Assuming everything’s golden during the James Webb Space Telescope launch next year, we’ll soon be equipped with a new uber-powerful machine that could, with ease, tell us whether planets like Proxima B have atmospheres and what they’re made of. It will also be our first chance to look directly at exo-planets.
For now, we still spot these stellar bodies by monitoring the light output of their host star. If we spot dips as planets cross between us and the star, we can get a rough idea of how big the planets are, what their mass is, and how close they’re orbiting. That tells us a lot, but not nearly enough to start loading people onto interstellar ships for a camping trip.