The stratosphere of WASP-121b

https://www.nasa.gov/feature/jpl/hubble-detects-exoplanet-with-glowing-water-atmosphere

Scientists have discovered the strongest evidence to date for a stratosphere on a planet outside our solar system, or exoplanet.
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"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, study co-author based at NASA's Ames Research Center in California's Silicon Valley. "We can now compare processes in exoplanet atmospheres with the same processes that happen under different sets of conditions in our own solar system."
Reporting in the journal Nature, scientists used data from NASA's Hubble Space Telescope to study WASP-121b, a type of exoplanet called a "hot Jupiter." Its mass is 1.2 times that of Jupiter, and its radius is about 1.9 times Jupiter's -- making it puffier.