Discovery of 4 mysterious 'mini-Neptune' exoplanets baffles scientists.

Astronomers have discovered four new "mini-Neptunes" exoplanets using the European Space Agency's exoplanet-hunting spacecraft, CHEOPS, after NASA's Transiting Exoplanet Survey Satellite (TESS) first tipped them off to the presence of these exoplanets. The newly found planets orbit different stars and are around the size of Neptune or slightly smaller, or about two to five times the size of Earth. The mini-Neptunes are farther out from their parent stars than typical hot Jupiters are, and their relatively cool temperatures could mean they still have atmospheres and clouds that the James Webb Space Telescope (JWST) could investigate.