Impact bombardment on the regular satellites of Jupiter and Uranus during an episode of giant planet migration

Abstract

The intensity and effects of early impact bombardment on the major satellites of the giant planets during an episode of giant planet migration is still poorly known. We use a combination of dynamical N-body and Monte Carlo simulations to determine impact probabilities, impact velocities, and expected masses that collide with these satellites to determine the chronology of impacts during the migration. Volatile loss through bombardment is typically 20% for Miranda, a few percents for the larger Uranian satellites and negligible for the Galilean satellites. Due to its small size and the high impact velocity there is a >99% chance that Miranda suffered a catastrophic impact that shattered the satellite. Subsequent re-accretion from a circum-Uranian ring could account for its peculiar surface morphology and low density. The probability to destroy Ariel and Umbriel is 15% and 1% for Titania and Oberon. Approximately 90% of the mass in planetesimals that passes through the Jovian and Uranian satellite systems (about $4{\mathrm{M}}_{\oplus }$ and $2{\mathrm{M}}_{\oplus }$ respectively) does so in about 15 Myr. This extremely rapid and intense bombardment causes repeated local crustal melting on all satellites. The combination of these effects results in an entirely different impact chronology than that of the inner solar system. We conclude that the simple extrapolation of the lunar chronology to the outer solar system satellites is not correct. The tail end (after 25 Myr) of the chronology function has an e-folding time of 100 Myr at Jupiter, but follows a cumulative Weibull distribution at Uranus, making direct comparisons between the gas and ice giant planets difficult. Based on our results the surfaces of the Uranian satellites, Callisto, and possibly Ganymede, are all about the same age, and are roughly 150 Myr younger than the timing of the dynamical instability.

arXiv comment24 pages, 5 figures, accepted for publication in Earth and Planetary Science Letters

References in corpus (19)

• Collisions between Gravity-Dominated Bodies: 2. The Diversity of Impact Outcomes during the End Stage of Planet Formation
• Collisions Between Gravity-Dominated Bodies: 1. Outcome Regimes and Scaling Laws
• Statistical Study of the Early Solar System's Instability with 4, 5 and 6 Giant Planets
• The timeline of the Lunar bombardment - revisited
• The Absolute Magnitude Distribution of Kuiper Belt Objects
• Oort Cloud and Scattered Disc formation during a late dynamical instability in the Solar System
• Accretion of Saturn's mid-sized moons during the viscous spreading of young massive rings: solving the paradox of silicate-poor rings versus silicate-rich moons
• Did Saturn's rings form during the Late Heavy Bombardment ?
• Dynamical Evidence for a Late Formation of Saturn's Moons
• The Size Distribution of Kuiper belt objects for D> 10 km
• NOTE: Explaining why the Uranian satellites have equatorial prograde orbits despite the large planetary obliquity
• The GENGA Code: Gravitational Encounters in N-body simulations with GPU Acceleration
• The size distribution of Jupiter Family comet nuclei
• Late veneer and late accretion to the terrestrial planets
• Constraints on the Orbital Evolution of Triton
• Reassessing the origin of Triton
• Tilting Saturn without tilting Jupiter: Constraints on giant planet migration
• Triton's Evolution with a Primordial Neptunian Satellite System
• A colossal impact enriched Mars' mantle with noble metals

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• Oort cloud Ecology II: The chronology of the formation of the Oort cloud
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• Cupid Is Not Doomed Yet: On the Stability of the Inner Moons of Uranus
• Did Uranus' regular moons form via a rocky giant impactor?