A first outside our solar system, an exoplanet named GJ 1132 b has gained a second atmosphere through volcanic activity after losing its original atmosphere. The Earth-sized rocky exoplanet located 41 light-years away from our Earth orbits a dwarf star and was believed to have hydrogen and helium gases in its atmosphere before losing it to the intense radiation of the young hot star it orbits. The evidence of a new atmosphere was found using the National Aeronautics and Space Administration’s (NASA) Hubble telescope.
Astronomers were surprised by the new findings as the new atmosphere contains a toxic mix of hydrogen, methane, and hydrogen cyanide. In addition, it also contains an aerosol haze similar to Earth which is a result of photochemically produced hydrocarbons. They also believe that the planet may have a thin crust that is only a few hundred feet thick. Also, the atmosphere is getting replenished by gases seeping through cracks on the planet’s surface which have molten lava beneath it oozing via volcanic fissures.
“It’s super exciting because we believe the atmosphere that we see now was regenerated, so it could be a secondary atmosphere,” study co-author of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, Raissa Estrela said. “We first thought that these highly irradiated planets could be pretty boring because we believed that they lost their atmospheres. But we looked at existing observations of this planet with Hubble and said, ‘Oh no, there is an atmosphere there.’”
GJ 1332 b is similar to earth in its size, density and age. Both planets even had a hydrogen-dominated atmosphere initially before cooling down. The data also shows that the atmospheric pressure is similar as well. However, the main difference is that the exoplanet is that it orbits too close to the red dwarf star.
The planet is tidally locked (one hemisphere always facing the sun like Moon orbits Earth) to its Sun and completes one orbit (elliptical) in just a day and a half with temperatures reaching 256 degree celsius. Also, the planet experiences another planet’s gravitational pull which leads to fractures in its surface making it look like a cracked eggshell. These conditions make the planet inhabitable, at least for now.
“The question is, what is keeping the mantle hot enough to remain liquid and power volcanism?” lead author from JPL, Mark Swain asked. “This system is special because it has the opportunity for quite a lot of tidal heating.”
Even with the help of the Hubble telescope, astronomers could not take a photograph of the unique exoplanet because it was too dim. However, scientists believe that they can observe it better using NASA’s upcoming James Webb Space Telescope which has infrared vision allowing to see down on the planet’s surface.
“If there are magma pools or volcanism going on, those areas will be hotter,” Swain explained. “That will generate more emission, and so they’ll be looking potentially at the actual geologic activity—which is exciting!”