Earth-sized exoplanet may have lost its original atmosphere, but gained a second one through volcanism
Published Date: 3/11/2021
Source: phys.org
Orbiting a red dwarf star 41 light-years away is an Earth-sized, rocky exoplanet called GJ 1132 b. In some ways, GJ 1132 b has intriguing parallels to Earth, but in other ways it is very different. One of the differences is that its smoggy, hazy atmosphere contains a toxic mix of hydrogen, methane and hydrogen cyanide. Scientists using NASA's Hubble Space Telescope have found evidence this is not the planet's original atmosphere, and that the first one was blasted away by blistering radiation from GJ 1132 b's nearby parent star. The so-called "secondary atmosphere" is thought to be formed as molten lava beneath the planet's surface continually oozes up through volcanic fissures. Gases seeping through these cracks seem to be constantly replenishing the atmosphere, which would otherwise also be stripped away by the star. This is the first time a secondary atmosphere has been detected on a world outside our solar system.