“Smaller rocky planets likely form their atmospheres through outgassing during their formation and later from subsequent tectonic processes like volcanism,” researcher Maggie Thompson of University of California, Santa Cruz told SYFY WIRE. “This outgassing process occurs because a rocky planet is heated due to radioactive decay, collisions, and leftover heat from the formation process.”
The primordial atmospheres of rocky planets like Earth may have been very different from what they were assumed to be. Thompson, planetary scientist Myriam Telus, and their team, who recently published a study in
Nature Astronomy, found that the atmospheres of Earthlike planets in the early universe were more likely to form by gases that escaped from the surface. Billions of years ago, space was chaotic as objects smashed into other objects and either accreted into larger bodies or were flung into the void. Meteorites are the debris left over from that chaos.