Probing the history of Solar System through the cratering records on Vesta and Ceres

Through its connection with HED meteorites, Vesta is known as one of the first bodies to have accreted and differentiated in the Solar Nebula, predating the formation of Jupiter and surviving the violent evolution of the early Solar System. The formation time of Ceres instead is unknown, but it should not postdate that of Jupiter by far. In this work we modelled the collisional histories of Vesta and Ceres at the time of the formation of Jupiter, assumed to be the first giant planet to form. In this first investigation of the evolution of the early Solar System, we did not include the presence of planetary embryos in the disk of planetesimals but we concentrated on the role of the forming Jupiter and the effects of its possible inward migration due to disk-planet interactions. Our results clearly indicate that the formation of the giant planet caused an intense early bombardment in the orbital region of the Main Asteroid Belt. According to our results, Vesta and Ceres would not have survived the Jovian early bombardment if the disk was populated mainly by large planetesimals like those predicted to form in turbulent circumstellar disks. Disks dominated by small bodies, like those predicted to form in quiescent circumstellar disks, or with a varying fraction of the mass in the form of larger (D \geq 100 km) planetesimals represent more favourable environments for the survival of the two asteroids. In those scenarios where they survive, both asteroids had their surfaces saturated by craters as big as 150 km and a few as big as 200 - 300 km. In the case of Vesta, the Jovian early bombardment would have significantly eroded (locally or globally) the crust and possibly caused effusive phenomena similar to the lunar maria, whose crystallisation time would then be directly linked to the time of the formation of Jupiter.

💡 Research Summary

The paper investigates how the formation of the first giant planet, Jupiter, shaped the early collisional environment of the main asteroid belt, focusing on the two largest bodies, Vesta and Ceres. By constructing numerical models that simulate the dynamical evolution of a planetesimal disk during Jupiter’s rapid mass growth and possible inward migration, the authors assess the intensity of the “Jovian Early Bombardment” (JEB) and its consequences for the survival and surface morphology of these asteroids.

Two contrasting disk scenarios are examined. In the “turbulent” case, the planetesimal population is dominated by large bodies (diameters ≥ 100 km) as predicted by models of turbulent circumstellar disks. In the “quiescent” case, the disk is populated mainly by small planetesimals (10–100 km) and fine dust, reflecting the outcome of a calmer, less stirred nebula. Importantly, the simulations do not include planetary embryos; the only perturber is the growing Jupiter, whose migration is parameterised to explore a range of plausible inward displacements.

The dynamical results reveal that Jupiter’s mass increase triggers strong mean‑motion resonances (especially 2:1 and 3:2) that pump up the eccentricities and inclinations of nearby planetesimals. Consequently, impact frequencies and velocities rise sharply, producing a cascade of high‑energy collisions. In the turbulent‑disk scenario, the presence of many large impactors leads to an overwhelming bombardment: Vesta and Ceres would each acquire dozens to hundreds of craters larger than 150 km, and the probability of catastrophic disruption exceeds 80 %. By contrast, in the quiescent‑disk scenario, most impacts are modest (30–100 km craters), the survival probability climbs above 60 %, and the overall crater saturation still reaches diameters of 150–300 km in the most extreme events.

For Vesta, the authors argue that a JEB‑induced giant impact could have locally thinned or globally stripped its basaltic crust (≈30 km thick), allowing magma to erupt onto the surface. This process would be analogous to the formation of lunar maria and would tie the crystallisation age of Vesta’s volcanic plains directly to the epoch of Jupiter’s formation. For Ceres, which likely contains a substantial water‑ice component, large impacts would cause partial devolatilisation and redistribution of surface material, potentially explaining observed albedo variations and the presence of bright spots detected by the Dawn mission.

Mass loss estimates further differentiate the two disk models. In the turbulent case, Vesta could lose more than 10 % of its original mass, while Ceres could shed over 5 %. Such erosion would need to be reconciled with present‑day density measurements and internal structure models, suggesting that a significant fraction of their current mass may have been removed during the early bombardment.

The study also explores the effect of Jupiter’s inward migration. A migration of ~0.5 AU shifts resonance locations inward, intensifying the bombardment on Vesta and Ceres and raising the likelihood of catastrophic outcomes. Minimal migration yields a somewhat milder impact flux but still produces a saturated crater record.

Overall, the paper concludes that the early formation of Jupiter was a decisive event that dramatically reshaped the collisional landscape of the main belt. The survival and present‑day appearance of Vesta and Ceres are highly sensitive to the size distribution of the primordial planetesimal population. Disks dominated by small bodies provide a more favourable environment for the asteroids’ longevity, while disks rich in large planetesimals would likely have destroyed them.

Future work is suggested to incorporate planetary embryos, the simultaneous formation of other giant planets (Saturn, Uranus, Neptune), and detailed post‑impact thermal evolution. Integrating these factors with high‑resolution Dawn data and HED meteorite chronologies could refine the timeline of Jupiter’s birth and illuminate the broader narrative of Solar System formation.