Free Astronomy Magazine May-June 2021

20 MAY-JUNE 2021 ASTRO PUBLISHING star. In a short period of time, it was reduced to a bare core about the size of Earth. To the surprise of astronomers, new observations from Hubble have un- covered a secondary atmosphere that has replaced the planet’s first atmosphere. It is rich in hydrogen, hydrogen cyanide, methane and ammonia, and also has a hydrocar- bon haze. Astronomers theorise that hydrogen from the original atmos- phere was absorbed into the planet’s molten magma mantle and is now being slowly released by vol- canism to form a new atmosphere. This second atmosphere, which con- New atmosphere forming on a rocky exoplanet F or the first time, scientists using the NASA/ESA Hubble Space Telescope have found evidence of volcanic activity reforming the at- mosphere on a rocky planet around a distant star. The planet, GJ 1132 b, has a similar density, size, and age to those of Earth. The planet GJ 1132 b appears to have begun life as a gaseous world with a thick blanket of atmosphere. Starting out at several times the ra- dius of Earth, this so-called “sub- Neptune” quickly lost its primordial hydrogen and helium atmosphere, which was stripped away by the in- tense radiation from its hot, young by NASA/ESA - Bethany Downer