New Model for Meteorite Minerals
A team from the Southwest Research Institute has presented a scenario, published in Science Advances, that could account for the formation and preservation of millimetre‑sized, spherical mineral grains found in the parent bodies of the most abundant meteorites.
The researchers propose that tiny, short‑lived satellites—dubbed mini‑moons—orbited larger protoplanets during the early Solar System. Repeated impacts and gravitational interactions would allow these mini‑moons to capture high‑temperature molten particles, encasing them within a protective layer.
When the mini‑moons eventually disintegrated, the enclosed grains would become incorporated into surrounding planetesimals. There, they could survive for billions of years, later being delivered to Earth as components of meteorites.
This model addresses longstanding questions in planetary science, notably why many meteorites contain uniform, round mineral grains of similar size. The mechanism explains both the concentration and long‑term survival of these structures despite the chaotic environment of the nascent Solar System.
Future work, including laboratory simulations and analysis of newly recovered meteorite samples, will test the viability of the mini‑moon hypothesis. Confirmation would fill a critical gap in our understanding of early solar evolution.