Origin of lowest density super-puff planet remains a hazy mystery

A thick layer of haze around the ultra-low-density planet Kepler-51d likely obscures not only the strange planet's composition, but also its origin, according to a new study. A team led by Penn State researchers used NASA's James Webb Space Telescope (JWST) to take a deeper look at the "super-puff" planet that defies planetary formation models. However, the thickest layer of haze found on a planet yet makes discerning the chemical elements in the planet's atmosphere—and any clues to the planet's formation—challenging.