Free Astronomy Magazine September-October 2024

52 SEPTEMBER-OCTOBER 2024 Webb cracks case of inflated exoplanet W hy is the warm gas-giant exoplanet WASP-107 b so puffy? Two independent teams of researchers have an an- swer. Data collected using NASA’s James Webb Space Telescope, com- bined with prior observations from NASA’s Hubble Space Telescope, show surprisingly little methane (CH4) in the planet’s atmosphere, indicating that the interior of WASP-107 b must be significantly hotter and the core much more massive than previously estimated. The unexpectedly high temperature is thought to be a result of tidal heating caused by the planet’s slightly non-circular orbit, and can by NASA/ESA/CSA Margaret W. Carruthers Christine Pulliam