Magnetism, iron minerals and life on Mars

Pierre Rochette (1) , Jérôme Gattacceca (1) , Vincent Chevrier (1) , Pierre-Étienne Mathé (1) , Michel Menvielle (2)

1 Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement
2 CETP - Centre d'étude des environnements terrestre et planétaires

A short critical review is provided on two questions linking magnetism and possible early life on Mars: (1) Did Mars have an Earth-like internal magnetic field, and, if so, during which period and was it a requisite for life? (2) Is there a connection between iron minerals in the martian regolith and life? We also discuss the possible astrobiological implications of magnetic measurements at the surface of Mars using two proposed instruments. A magnetic remanence device based on magnetic field measurements can be used to identify Noachian age rocks and lightning impacts. A contact magnetic susceptibility probe can be used to investigate weathering rinds on martian rocks and identify meteorites among the small regolith rocks. Both materials are considered possible specific niches for microorganisms and, thus, potential astrobiological targets. Experimental results on analogues are presented to support the suitability of such in situ measurements.

Mots clés: Early life; Mars; Magnetism; Iron minerals

Domaines: Planétologie et astrophysique de la terre [astro-ph.EP]; Géophysique [physics.geo-ph]

Pierre Rochette, Jérôme Gattacceca, Vincent Chevrier, Pierre-Étienne Mathé, Michel Menvielle. Magnetism, iron minerals and life on Mars. Astrobiology, 2006, 6 (3), pp.423-436. ⟨10.1089/ast.2006.6.423⟩. ⟨hal-00112784⟩