The Kepler-51 system hosts three ultra-light “super-puff” planets with massive atmospheres and tiny cores. New JWST observations failed to detect atmospheric signatures, suggesting thick hydrocarbon haze and deepening the mystery of how such worlds form.​The Kepler-51 system hosts three ultra-light “super-puff” planets with massive atmospheres and tiny cores. New JWST observations failed to detect atmospheric signatures, suggesting thick hydrocarbon haze and deepening the mystery of how such worlds form.  ​ science