Non-technical Talk by Prof. Jonathan Fortney (U. of California, Santa Cruz) 
Apr. 9, 2025

Over 6000 planets have now been found around other stars, but we only have information about what their atmospheres are like for a few dozen.  NASA's powerful James Webb Space Telescope (JWST), which features a 20-foot mirror in space, is currently being used to understand planetary atmospheres.  Prof. Fortney explains how we can look for atmospheres around rocky planets the size of the Earth, and how his group and others are already measuring the abundances of molecules like water, methane, ammonia, and carbon dioxide in the atmospheres of larger planets, of sizes similar to Neptune and Jupiter.  And he tells us what astronomers are looking forward to in the next year or two with JWST.