Excited for the second year of our new Physics with Astrophysics degree program at the University of Lincoln! Right now, I’m fully immersed, working on one of our new modules called “The Solar System and Exoplanets.” We’re diving deep into how planets form and trying to unravel the mystery of the huge variety of exoplanets we keep discovering. Check out this quick video for a taste of what we’re digging into in the module.
The apparent lack of planets with radii 1.5–2 times that of Earth is known as the Sub-Neptune radius valley. First noted in 2011, a bimodality in the Kepler exoplanet population was ascribed to the lack of substantial gas atmospheres on close-in, low-mass planets. It was mentioned that this trait could support the growing theory that atmospheric mass loss could be caused by photoevaporation. This would result in a population of planets with thick envelopes dominated by helium and hydrogen with bigger radii at higher separations from their parent stars, and a population of naked, rocky cores with lower radii at small separations.
