Exoplanet evolution? Mini-Neptunes may shed their atmospheres and become super-Earths

New research suggests that stellar radiation is stripping away the “fluffy” atmospheres of exoplanets slightly smaller than Neptune, leaving behind their rocky cores and transforming them into worlds more closely resembling Earth. 

In the 1990s, astronomers confirmed the existence of planets outside the solar system. Known as exoplanets, they are one of the most fascinating subjects of modern astronomy. Spacecraft such as NASA’s pioneering Kepler observatory and Transiting Exoplanet Survey Satellite (TESS) have scanned the skies searching for periodic dips in the brightness of nearby stars. This blinking is a sign that a star is hosting a planet, which has crossed the face of the star and temporarily blocked its light.