For the first time outside of our solar system, an exoplanet named GJ 1132 b has gained a second atmosphere through volcanic activity after losing its original atmosphere. The rocky Earth-size 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 intense radiation from the hot young star it orbits. Evidence for 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. Additionally, it also contains an Earth-like aerosol mist that is the result of photochemically produced hydrocarbons. They also believe that the planet may have a thin crust that is only a few hundred feet thick. Additionally, the atmosphere is being replenished by gases seeping through cracks on the planet’s surface, which have molten lava underneath oozing through volcanic fissures.
“It’s very exciting because we think the atmosphere we see now was regenerated, so it could be a secondary atmosphere,” said Raissa Estrela, study co-author from NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “We first thought that these highly irradiated planets might be pretty boring because we thought they had lost their atmospheres. But we looked at the existing observations of this planet with Hubble and said, ‘Oh no, there’s an atmosphere there.’
GJ 1332 b is similar to earth in 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 also similar. However, the main difference is that the exoplanet is orbiting too close to the red dwarf star.
The planet is locked by tides (a hemisphere always facing the sun as the Moon orbits the Earth) to its Sun and completes an orbit (elliptical) in just a day and a half with temperatures reaching 256 degrees Celsius. Also, the planet experiences the gravitational pull of another planet that leads to fractures on its surface that make it look like a cracked eggshell. These conditions make the planet habitable, at least for now.
“The question is, what keeps the mantle warm enough to stay liquid and enhance volcanism?” JPL lead author, asked Mark Swain. “This system is special because it has the opportunity for a lot of tidal heating.”
Even with the help of the Hubble telescope, astronomers were unable to take a picture of the single exoplanet because it was too dark. However, scientists believe they can better observe it using NASA’s upcoming James Webb Space Telescope, which has an infrared view that allows you to see the planet’s surface.
“If there are pools of magma or volcanic activity, those areas will be hotter,” Swain explained. “That will generate more emissions, so potentially they will be looking at the actual geological activity, which is exciting!”