Where does the air we breathe and the water we drink come from, and how do other rocky planets wrap themselves in an atmosphere? The extreme temperatures of the magma worlds that birthed these planets should have caused these gaseous elements to vaporize and escape into space. Yet, a new study reveals a previously unsuspected preservation mechanism:
Gas bubbles sinking into an ocean of magma! The reason? They are attached to metal droplets. This means the formation of a rocky planet's metallic core is directly linked to the burial of atmospheric components.
This "attachment" mechanism reconciles the sheer violence of planet formation with the preservation of highly volatile atmospheric ingredients. Furthermore, it applies to all rocky planets across our solar system and beyond—provided that metal forms early in the planet's history.
This is published in the journal Science (oct. 1rst 2026)
Link of the article: https://www.science.org/doi/10.1126/science.aef2542
Link to the INSU news: Pourquoi les planètes ne manquent pas d'air ? | CNRS Terre & Univers
Image of a sample
