Collisional heating of icy planetesimals. I. Catastrophic collisions

Abstract

Planetesimals in the primordial disc may have experienced a collisional cascade. If so, the comet nuclei later placed in the Kuiper belt, scattered disc, and Oort Cloud would primarily be fragments and collisional rubble piles from that cascade. However, the heating associated with the collisions cannot have been strong enough to remove the hypervolatiles that are trapped within more durable ices, because comet nuclei are rich in hypervolatiles. This places constraints on the diameter of the largest bodies allowed to participate in collisional cascades, and limits the primordial disc lifetime or population size. In this paper, the thermophysical code NIMBUS is used to study the thermal evolution of planetesimals before, during, and after catastrophic collisions. The loss of CO during segregation of $\mathrm{C}{\mathrm{O}}_2:\mathrm{CO}$ mixtures and during crystallisation of amorphous ${\mathrm{H}}_2\mathrm{O}$ is calculated, as well as mobilisation and internal relocation of $\mathrm{C}{\mathrm{O}}_2$. If an amorphous ${\mathrm{H}}_2\mathrm{O}$ host existed, and was protected by a $\mathrm{C}{\mathrm{O}}_2:\mathrm{CO}$ heat sink, only diameter $D<20\mathrm{km}$ (inner disc) and $D<64\mathrm{km}$ (outer disc) bodies could have been involved in a collisional cascade. If $\mathrm{C}{\mathrm{O}}_2$ was the only CO host, the critical diameters drop to $D<20$-$32\mathrm{km}$. Avoiding disruption of larger bodies requires a primordial disc lifetime of $<9\mathrm{Myr}$ at $15\mathrm{au}$ and $<50$-$70\mathrm{Myr}$ at $30\mathrm{au}$. Alternatively, if a $450\mathrm{Myr}$ disc lifetime is required to associate the primordial disc disruption with the Late Heavy Bombardment, the disc population size must have been 6-60 times below current estimates.

arXiv comment20 pages, 11 figures. This is a pre-copyedited, author-produced PDF of an article accepted for publication in MNRAS following peer review

References in corpus (45)

• Rapid planetesimal formation in turbulent circumstellar discs
• Streaming Instabilities in Protoplanetary Disks
• Origin of the Structure of the Kuiper Belt during a Dynamical Instability in the Orbits of Uranus and Neptune
• The Size Distribution of Trans-Neptunian Bodies
• Statistical Study of the Early Solar System's Instability with 4, 5 and 6 Giant Planets
• Dynamics of the giant planets of the solar system in the gaseous proto-planetary disk and relationship to the current orbital architecture
• The c2d Spitzer spectroscopic survey of ices around low-mass young stellar objects II: CO2
• Dynamical Evolution of the Early Solar System
• A Sawtooth-like Timeline for the First Billion Year of Lunar Bombardment
• The Active Centaurs
• Formation of Kuiper Belt Binaries by Gravitational Collapse
• The Absolute Magnitude Distribution of Kuiper Belt Objects
• Oort Cloud and Scattered Disc formation during a late dynamical instability in the Solar System
• Full Numerical Simulations of Catastrophic Small Body Collisions
• The Evidence for Slow Migration of Neptune from the Inclination Distribution of Kuiper Belt Objects
• Constructing the secular architecture of the solar system II: The terrestrial planets
• Numerical simulations of impacts involving porous bodies: I. Implementing sub-resolution porosity in a 3D SPH Hydrocode
• Gravitational slopes, geomorphology, and material strengths of the nucleus of comet 67P/Churyumov-Gerasimenko from OSIRIS observations
• The Scattered Disk as the source of the Jupiter Family comets
• SPH calculations of asteroid disruptions: The role of pressure dependent failure models
• On the Migration of Jupiter and Saturn: Constraints from Linear Models of Secular Resonant Coupling with the Terrestrial Planets
• Dynamical evidence for an early giant planet instability
• The Physics of Protoplanetesimal Dust Agglomerates. IV. Towards a Dynamical Collision Model
• The thermal, mechanical, structural, and dielectric properties of cometary nuclei after Rosetta
• Demographics of Planetesimals Formed by the Streaming Instability
• Thermal evolution and sintering of chondritic planetesimals
• Comets as collisional fragments of a primordial planetesimal disk
• The Luminosity Function of the Hot and Cold Kuiper belt Populations
• Formation of bi-lobed shapes by sub-catastrophic collisions: A late origin of comet 67P/C-G's structure
• Comet 67P/Churyumov-Gerasimenko: Constraints on its origin from OSIRIS observations
• Effects of friction and plastic deformation in shock-comminuted damaged rocks on impact heating
• How primordial is the structure of comet 67P/C-G? Combined collisional and dynamical models suggest a late formation
• Comet formation in collapsing pebble clouds. What cometary bulk density implies for the cloud mass and dust-to-ice ratio
• Testing the Jeans, Toomre and Bonnor-Ebert concepts for planetesimal formation: 3D streaming instability simulations of diffusion regulated formation of planetesimals
• Thermophysical evolution of planetesimals in the Primordial Disk
• The Collisional Divot in the Kuiper belt Size Distribution
• On the Origin and Thermal Stability of Arrokoths and Plutos Ices
• The Sublimative Evolution of (486958) Arrokoth
• Airfall on Comet 67P/Churyumov-Gerasimenko
• Modelling the water and carbon dioxide production rates of Comet 67P/Churyumov-Gerasimenko
• Volatility of Sodium in Carbonaceous Chondrites at Temperatures Consistent with Low-Perihelia Asteroids
• Entrapment of CO in CO2 ice
• Collisional heating and compaction of small bodies: Constraints for their origin and evolution
• Modification of icy planetesimals by early thermal evolution and collisions: Constraints for formation time and initial size of comets and small KBOs
• CO2-driven surface changes in the Hapi region on Comet 67P/Churyumov-Gerasimenko