Puffy planets lose atmospheres, become super-Earths: Finding represents first detections of atmospheric loss in
Astronomers have identified two different cases of “mini-Neptune” planets that are losing their puffy atmospheres and likely transforming into super-Earths. Radiation from the planets’ stars is stripping away their atmospheres, driving hot gas to escape like steam from a pot of boiling water. “Most astronomers suspected that young, small mini-Neptunes must have evaporating atmospheres,” says […]