800 Million Years Ago, a Catastrophic Asteroid Breakup Rained Fire on the Inner Solar System
800 million years ago, a 100 km asteroid known as the parent body of the Eulalia family broke apart in a catastrophic collision.
The debris entered the J3:1 orbital resonance with Jupiter, which acted as a gravitational funnel, scattering asteroid fragments across the inner solar system.
Evidence from the Moon, including cratering patterns and radiometric dating of glass beads, confirms an intense bombardment period beginning around 800 million years ago.
Researchers hypothesize this event may have triggered significant planetary changes, including climate shifts, volcanic activity, and surface-altering impacts on Earth, Mars, and Venus.
The Eulalia Breakup
The Eulalia family consists of asteroids with shared geological origins, originating from a single larger parent body.
The fragmentation occurred near the J3:1 resonance point; while some pieces were immediately displaced, others entered this trajectory over 150 million years due to the Yarkovsky effect (thermal acceleration).
Fragments from this event likely constitute many currently observed Near-Earth asteroids, as indicated by samples from Ryugu and Bennu.
Planetary Impacts
Earth: The bombardment likely contributed to the Bitter Springs Anomaly, a period of major carbon cycle disruption. Increased dust from impacts may have triggered cooling, potentially influencing marine life evolution before the "Snowball Earth" period.
The Moon: The 93 km Copernicus crater and a clustering of lunar impact glass date back to this epoch, providing a primary record of the bombardment.
Mars: Repeated asteroid impacts may have destabilized magma reservoirs, causing a surge in volcanic caldera formation 800 million years ago.
Venus: Speculative models suggest that the barrage of debris could have sparked a catastrophic, planet-wide volcanic resurfacing event roughly 650 million years ago.
Scientific Context
The researchers utilized collisional and dynamical models to trace the orbital history of the Eulalia family.
While the connection between the asteroid shower and major planetary events is compelling, the authors characterize the theories regarding Earth's climate and Venus's resurfacing as speculative hypotheses requiring further evidence.