Interpebble contact radius in a comet nucleus

Abstract

In recent years, the gravitational collapse of pebble clumps in the early Solar System has been regarded as a plausible scenario for the origin of comets. In this context, ``pebbles'' represent mm- to cm-sized dust aggregates composed of (sub)micron-sized dust particles, and the structure of km-sized comets is thought to be an agglomerate of pebbles. The contact radius for pebble-pebble contacts was modelled in an earlier study; however, the pressure dependence of the interpebble contact radius was not considered. Here, we revisit the interpebble contact radius in a comet nucleus. We calculated the interpebble contact radius based on JKR contact theory, and we took into consideration the effect of lithostatic pressure. We found that the interpebble contact radius varies with depth from the surface, and the earlier model underestimated it by one order of magnitude at the centre of the comet nucleus.

9 pages, 6 figures. Accepted for publication in MNRAS

References in corpus (18)

• Evidence for the formation of comet 67P/Churyumov-Gerasimenko through gravitational collapse of a bound clump of pebbles
• CO Depletion in Protoplanetary Disks: A Unified Picture Combining Physical Sequestration and Chemical Processing
• Comets formed in solar-nebula instabilities! -- An experimental and modeling attempt to relate the activity of comets to their formation process (corrigendum included)
• Formation of pebble-pile planetesimals
• Submillimetre-sized dust aggregate collision and growth properties
• Transmission Electron Microscopy Study of the Morphology of Ices Composed of H2O, CO2, and CO on Refractory Grains
• Formation of Comets
• Full-field modeling of heat transfer in asteroid regolith: Radiative thermal conductivity of polydisperse particulates
• On the stickiness of CO${}_2$ and H${}_2$O ice particles
• Thermal conductivity of porous aggregates
• Thermal conductivity and coordination number of compressed dust aggregates
• The radial structure of planetary bodies formed by the streaming instability
• Thermal inertias of pebble-pile comet 67P/Churyumov-Gerasimenko
• Undulating compression and multi-stage relaxation in a granular column consisting of dust particles or glass beads
• Threshold velocity for collisional growth of porous dust aggregates consisting of cohesive frictionless spheres
• A method to distinguish between micro- and macro-granular surfaces of small Solar System bodies
• Collisional growth efficiency of dust aggregates and its independence of the strength of interparticle rolling friction
• Revisiting sticking property of submillimetre-sized aggregates