Planetary Magnetic Dynamo Effect on Atmospheric Protection of Early Earth and Mars

Research areas:
Year:
2007
Authors:
  • V. Dehant
  • H. Lammer
  • Y. N. Kulikov
  • J. -M. Griessmeier
  • D. Breuer
  • Olivier Verhoeven
  • O. Karatekin
  • T. Van Hoolst
  • O. Korablev
  • P. Lognonne
Editor:
Fishbaugh, KE; Lognonne, P; Raulin, F; Des Marais, DJ; Korablev, O
Volume:
24
Book title:
Workshop on Geology and Habitability of Terrestrial Planets
Series:
Space Science Series of ISSI
Pages:
279-300
ISSN:
1385-7525
BibTex:
Abstract:
In light of assessing the habitability of Mars, we examine the impact of the magnetic field on the atmosphere. When there is a magnetic field, the atmosphere is protected from erosion by solar wind. The magnetic field ensures the maintenance of a dense atmosphere, necessary for liquid water to exist on the surface of Mars. We also examine the impact of the rotation of Mars on the magnetic field. When the magnetic field of Mars ceased to exist (about 4 Gyr ago), atmospheric escape induced by solar wind began. We consider scenarios which could ultimately lead to a decrease of atmospheric pressure to the presently observed value of 7 mbar: a much weaker early martian magnetic field, a late onset of the dynamo, and high erosion rates of a denser early atmosphere.