Hubble has detected glowing water molecules around a planet outside our solar system for the first time. And, this gives us the strongest evidence to date for a stratosphere on an exoplanet.
“This result is exciting because it shows that a common trait of most of the atmospheres in our solar system — a warm stratosphere — also can be found in exoplanet atmospheres,” said Mark Marley, who is the study’s co-author based at NASA’s Ames Research Center in California’s Silicon Valley, in a news release. “We can now compare processes in exoplanet atmospheres with the same processes that happen under different sets of conditions in our own solar system.”
A stratosphere is a layer of atmosphere above the troposphere in which temperature does not fall as altitude increases. Reporting in the journal Nature, researchers say although the planet has a stratosphere, it’s totally uninhabitable, with temperatures of blazing 4,600 degrees Fahrenheit (2,500 degree Celsius), which is hot enough to boil iron.
The exoplanet named WASP-121b has a mass 1.2 times that of Jupiter, and radius about 1.9 times. It is located approximately 900 light-years from Earth. Compared to Jupiter which revolves around our sun once every 12 years, WASP-121b has an orbital period of just 1.3 days. Moreover, the exoplanet is so close to its star that if it got any closer, the star’s gravity would start ripping it apart, researchers say.
The paper, entitled ‘An ultrahot gas-giant exoplanet with a stratosphere,’ has been reported in the journal Nature.