A distant exoplanet may be surrounded by a vaporous atmosphere, according to new measurements from the James Webb Space Telescope.
The planet GJ 1214b, a mini-Neptune — the most common type of planet in the galaxy — is in a close orbit around a red dwarf star, taking 1.6 days to orbit.
The planet is shrouded in a layer of cloud or fog that prevents most observations, but a team led by Eliza Kempton University of Maryland It compensated for this by seeing the planet in a complete orbit.
It’s 279˚C during the day and just 165˚C at night – an imbalance only possible if the atmosphere contains heavier molecules like water.
„We think we’re detecting steam, but that’s challenging because steam absorption overlaps with methane absorption,” says Kempton.
„We can’t say 100% that we detected water vapor and not methane. However, we see this evidence in both hemispheres of the planet, which increases our confidence that water is indeed present.”
JWST and Exoplanet Science
To learn more about what the Webb Telescope can do to observe planets beyond our solar system, watch our video interview with astrophysicist Dr Hannah Wakeford from the University of Bristol.