Triggering the Activation of Main Belt Comets: The Effect of Porosity
arXiv:1801.08247 · doi:10.3847/1538-4357/aaa7f3
Abstract
It has been suggested that the comet-like activity of Main Belt Comets is due to the sublimation of sub-surface water-ice that is exposed when these objects are impacted by meter-sized bodies. We recently examined this scenario and showed that such impacts can in fact excavate ice and present a plausible mechanism for triggering the activation of MBCs (Haghighipour et al. 2016). However, because the purpose of that study was to prove the concept and identify the most viable ice-longevity model, the porosity of the object and the loss of ice due to the heat of impact were ignored. In this paper, we extend our impact simulations to porous materials and account for the loss of ice due to an impact. We show that for a porous MBC, impact craters are deeper, reaching to approximately 15 m implying that if the activation of MBCs is due to the sublimation of sub-surface ice, this ice has to be within the top 15 m of the object. Results also indicate that the loss of ice due to the heat of impact is negligible, and the re-accretion of ejected ice is small. The latter suggests that the activities of current MBCs are most probably from multiple impact sites. Our study also indicates that in order for sublimation from multiple sites to account for the observed activity of the currently known MBCs, the water content of MBCs (and their parent asteroids) needs to be larger than the values traditionally considered in models of terrestrial planet formation.
arXiv comment22 pages, 8 figures, 2 tables, accepted for publication in ApJ
References in corpus (16)
- Catastrophic disruptions revisited
- Numerical simulations of impacts involving porous bodies: I. Implementing sub-resolution porosity in a 3D SPH Hydrocode
- Main-Belt Comet P/2008 R1 (Garradd)
- Collisions between equal sized ice grain agglomerates
- Discovery of Main-Belt Comet P/2006 VW139 by Pan-STARRS1
- A smooth particle hydrodynamics code to model collisions between solid, self-gravitating objects
- Potential Jupiter-Family Comet Contamination of the Main Asteroid Belt
- Observational and Dynamical Characterization of Main-Belt Comet P/2010 R2 (La Sagra)
- Dynamical Constraints on the Origin of Main Belt Comets
- Sublimation-Driven Activity in Main-Belt Comet 313P/Gibbs
- Main-Belt Comet P/2012 T1 (PANSTARRS)
- Rotationally Induced Surface Slope-Instabilities and the Activation of CO2 Activity on Comet 103P/Hartley 2
- Discovery and Characteristics of the Rapidly Rotating Active Asteroid (62412) 2000 SY178 in the Main Belt
- Triggering Sublimation-Driven Activity of Main Belt Comets
- SPH-based simulation of multi-material asteroid collisions
- Impact inducted surface heating by planetesimals on early Mars
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- Realistic collisional water transport during terrestrial planet formation: Self-consistent modeling by an N-body--SPH hybrid code
- Collision Chains among the Terrestrial Planets. III. Formation of the Moon
- Exocomets in the Proxima Centauri system and their importance for water transport
- Collisional formation of massive exomoons of super-terrestrial exoplanets
- Nucleus of active asteroid 358P/Pan-STARRS (P/2012 T1)
- Activity of main-belt comet 324P/La Sagra
- Merging Criteria for Planetesimal Collisions