TRANSCRIPT: GJ 1132b Update for 04/06/17 Exoplanet Atmospheres

At first glance, this story might not seem to have much of a connection to the question of life in the universe, the planet I'm about to discuss is probably about as hostile and uninhabitable as they get, but in fact it answers a long-standing question about exoplanet atmospheres and just where they can exist. That, in turn, has implications for where life, at least as we know it here on earth, can arise.

GJ 1132b is an exoplanet discovered around a star located about 39 light years away from us. It's a small planet, just a bit larger than Earth and is thought to be rocky. It's been called a potential Venus twin due likely having a very high surface temperature similar to Venus, though it's probably even hotter. It was also thought to likely have some type of thick atmosphere, though the composition was unknown. This atmosphere has now been directly observed.

Scientists have observed the atmospheres of exoplanets before, though up until now it was limited to gas giants and planets much larger than earth. This is the first time they've directly observed a planet with an atmosphere that is roughly in earth's class as far as size, but the similarities end there.

John Southworth of Keele University in the UK and colleagues used the European Southern Observatory or ESO, a hotbed for exoplanet discoveries as of late, to confirm the size of the planet by studying it as it transited in front of its star. But they saw something else within the data. One of the wavelengths of light they were studying seemed to be blocked by an atmosphere of some type, though its composition isn't yet fully understood.

This has an important implication regarding stars that can have habitable planets in the universe. Stars fall into different classes, our own sun being a G type yellow dwarf. GJ 1132b's star is an M-type dwarf, by far the most common kind of star in the Milky Way, in fact Trappist - 1 is in that class. GJ 1132, the parent star of the planet, is a type of star that tends to be pretty active and, up until now, it was unclear if any planets orbiting very near such a star could hold onto their atmospheres. For our kind of life here on earth, obviously having an atmosphere is quite important.

GJ 1132b seemingly answers the question. Yes, planets orbiting close to at least some M type stars can hold onto atmospheres. That potentially opens up a huge amount of stars to the possibility of harboring earth-like planets. But as far as GJ 1132b is concerned, it's not earth-like at all.

But what might GJ 1132b's atmosphere look like? One hypothesis based on the data is that it might be largely made up of water vapor, basically a steam bath world, or a world high in methane. The planet is close to its star, so it would probably be tidally locked, always presenting the same face towards the star. That's about all that can be said though.

But in the future this world is set to be a priority for study, especially with the James Webb Space Telescope. Other than Venus, this is the first roughly earth-sized planet with an atmosphere that we can study. As the facts about the planet come out, it will become a planet that we can envision what it might be like better than most other exoplanets. Scientists should eventually be able to work out the planet's color, what sort of winds it has, and even what sunsets might look like on this world.

Thanks for listening! I am futurist and science fiction author John Michael Godier currently hard at work preparing content for the new channel and be sure to check out my books at your favorite online book retailer and subscribe to my channel for regular, in-depth explorations into the interesting, weird and unknown aspects of this amazing universe in which we live