They have been called “radium valley” and “peas in a pod” and are two very interesting planetary phenomena studied by astronomers. The first refers to the rarity of planets with masses between a super-Earth or a mini-Neptune and the other to the regular arrangement and almost homogeneous size of the different planets in a solar system.
In a study conducted by Rice University’s Cycles of Life-Essential Volatile Elements in Rocky Planets (CLEVER) project, an international team of astrophysicists provides a new model that explains the interplay of forces acting on newly formed planets and that could explain these two enigmas.
The group of scientists used a supercomputer to run a planetary migration model that simulated the first 50 million years of the system’s development. In their model, protoplanetary disks of gas and dust also interact with migrating planets, pulling them closer to their parent stars and locking them into resonant orbital chains.
Project manager André Izidoro explained: “The migration of young planets towards their host stars creates crowding and often leads to catastrophic collisions that strip the planets of their hydrogen-rich atmospheres.
“This means that giant impacts, like the one that formed our moon, are probably a generic result of planet formation,” he added.
This latest research suggests that planets come in two variants, consisting of dry, rocky planets that are 50 percent larger than Earth (super-Earths) and ice- and water-rich planets about 2.5 times larger than Earth. Earth size (mini-Neptunes).
Thanks to this research and the new James Webb Space Telescope, we will be able to understand the history of a solar system by going much deeper into its evolution.