Impact induced surface heating by planetesimals on early Mars
- Author(s)
- Thomas Maindl, Rudolf Dvorak, Helmut Lammer, Manuel Güdel, Christoph Schäfer, Elke Pilat-Lohinger
- Abstract
Aims: We investigate the influence of impacts of large planetesimals and small planetary embryos on the early Martian surface on the hydrodynamic escape of an early steam atmosphere that is exposed to the high soft X-ray and extreme-ultraviolet (EUV) flux of the young Sun.
Methods: Impact statistics in terms of number, masses, velocities, and angles of asteroid impacts onto early Mars are determined via n-body integrations. Based on these statistics, smoothed particle hydrodynamics (SPH) simulations result in estimates of energy transfer into the planetary surface material and the resulting surface heating. For the estimation of the atmospheric escape rates we applied a soft X-ray and EUV absorption model and a 1D upper atmosphere hydrodynamic model to a magma ocean-related catastrophically outgassed steam atmosphere with surface pressure values of 52 bar H2O and 11 bar CO2.
Results: The estimated impact rates and energy deposition onto an early Martian surface can account for substantial heating. The energy influx and conversion rate into internal energy is probably sufficient to keep a shallow magma ocean liquid for an extended period of time. Higher surface temperatures keep the outgassed steam atmosphere longer in vapor form and therefore enhance its escape to space within ~0.6 Myr after its formation.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Österreichische Akademie der Wissenschaften (ÖAW), Eberhard Karls Universität Tübingen
- Journal
- Astronomy & Astrophysics
- Volume
- 574
- No. of pages
- 7
- ISSN
- 0004-6361
- DOI
- https://doi.org/10.1051/0004-6361/201424256
- Publication date
- 02-2015
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- Keywords
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/8397f8fd-868a-4e3c-937d-44550f3c2e49