Scientists believe that an exoplanet discovered last year has oxygen in its atmosphere, potentially the first time the gas has been detected on a rocky planet outside the solar system.
Earth-sized exoplanet GJ 1132b, which was discovered last year just 39 light-years away from our Earth, has a thin atmosphere containing oxygen, according to a new study published in The Astrophysical Journal.Harvard astronomer Laura Schaefer, who led the research at the Harvard-Smithsonian Center for Astrophysics, explained that the planet is very hot because it orbits its star at a distance of just 1.4 million miles (2.25 million km).
GJ 1132b takes just 1.6 days to circle its star, and it has a temperature of around 250 degrees Celsius.
“On cooler planets, oxygen could be a sign of alien life and habitability. But on a hot planet like GJ 1132b, it’s a sign of the exact opposite — a planet that’s being baked and sterilized,” Schaefer said.
Being so close to its star, the planet is subjected to a large amount of UV light, which breaks apart water molecules into hydrogen and oxygen. Hydrogen escapes into space more readily than oxygen, and scientists think that oxygen may still be present on the exoplanet as a result of this process.
“This planet might be the first time we detect oxygen on a rocky planet outside the solar system,” said Professor Robin Wordsworth, co-author of the research paper.
The scientists believe that GJ 1132b might have started with a steamy, water-rich atmosphere. Their research might help astronomers to understand the evolution of Venus, which is about 108 million km from our Sun (the Earth is about 150 million km away) and has an average temperature of 450 degrees Celsius.