Ultra-Short-Period Exoplanet Defies Atmosphere Expectations, JWST Finds
JWST observations of TOI-561 b, a rocky world with a ~10-hour orbit close to its star, reveal a volatile-rich atmosphere and heat redistribution consistent with a magma-ocean–atmosphere cycle. This challenges the long-held view that such irradiated planets shed their atmospheres and revises the idea of the cosmic shoreline separating atmospheric from airless worlds.