RECONCILING the ORBITAL and PHYSICAL PROPERTIES of the MARTIAN MOONS

Research output: Contribution to journalArticle

Abstract

The origin of Phobos and Deimos is still an open question. Currently, none of the three proposed scenarios for their origin (intact capture of two distinct outer solar system small bodies, co-accretion with Mars, and accretion within an impact-generated disk) are able to reconcile their orbital and physical properties. Here we investigate the expected mineralogical composition and size of the grains from which the moons once accreted assuming they formed within an impact-generated accretion disk. A comparison of our results with the present-day spectral properties of the moons allows us to conclude that their building blocks cannot originate from a magma phase, thus preventing their formation in the innermost part of the disk. Instead, gas-to-solid condensation of the building blocks in the outer part of an extended gaseous disk is found as a possible formation mechanism as it does allow reproducing both the spectral and physical properties of the moons. Such a scenario may finally reconcile their orbital and physical properties, alleviating the need to invoke an unlikely capture scenario to explain their physical properties.

Details

Authors
  • T. Ronnet
  • P. Vernazza
  • O. Mousis
  • B. Brugger
  • P. Beck
  • B. Devouard
  • O. Witasse
  • F. Cipriani
External organisations
  • Laboratoire d'Astrophysique de Marseille (LAM)
  • University Grenoble Alpes
  • Aix-Marseille University
  • European Space Research and Technology Centre (ESA/ESTEC)
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Astronomy, Astrophysics and Cosmology

Keywords

  • planets and satellites: composition, planets and satellites: formation, planets and satellites: individual (Phobos, Deimos)
Original languageEnglish
Article number109
JournalAstrophysical Journal
Volume828
Issue number2
Publication statusPublished - 2016 Sep 10
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes