Magnets and Mars
Magnetic Properties Experiments on the Mars Pathfinder Lander: Preliminary Results
S. F. Hviid, M. B. Madsen, H. P. Gunnlaugsson, W. Goetz, J. M. Knudsen, R. B. Hargraves, P. Smith, D. Britt, A. R. Dinesen, C. T. Mogensen, M. Olsen, C. T. Pedersen, L. Vistisen
Many of the particles currently suspended in the martian atmosphere are magnetic, with an average saturation magnetization of about 4 A·m2/kg (amperes times square meters per kilogram). The particles appear to consist of claylike aggregates stained or cemented with ferric oxide (Fe2O3); at least some of the stain and cement is probably maghemite (-Fe2O3). The presence of the phase would imply that Fe2+ ions leached from the bedrock, passing through a state as free Fe2+ ions dissolved in liquid water. These particles could be a freeze-dried precipitate from ground water poured out on the surface. An alternative is that the magnetic particles are titanomagnetite occurring in palagonite and inherited directly from a basaltic precursor.
S. F. Hviid, M. B. Madsen, H. P. Gunnlaugsson, W. Goetz, J. M. Knudsen, A. R. Dinesen, C. T. Mogensen, M. Olsen, C. T. Pedersen, L. Vistisen, Oersted Laboratory, Niels Bohr Institute for Astronomy, Physics, and Geophysics, University of Copenhagen, Copenhagen, Denmark.
R. B. Hargraves, Department of Geosciences, Princeton University, Princeton, NJ 08544, USA.
P. Smith and D. Britt, Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA.
Both Viking landers had a weak and a strong magnet mounted on the backhoe of their soil samplers ....More....http://www.sciencemag.org/cgi/content/full/278/5344/1768
Posted by Jay Roberts at 04:02 AM | Permalink