TY - JOUR
T1 - Search for magnetic minerals in Martian rocks
T2 - Overview of the Rock Abrasion Tool (RAT)magnet investigation on Spirit and Opportunity
AU - Goetz, Walter
AU - Leer, Kristoffer
AU - Gunnlaugsson, Haraldur P.
AU - Bartlett, Paul
AU - Basso, Brandon
AU - Bell, Jim
AU - Bertelsen, Preben
AU - Binau, Charlotte S.
AU - Chu, Phillip C.
AU - Gorevan, S.
AU - Hansen, Mikkel F.
AU - Hviid, Stubbe F.
AU - Kinch, Kjartan M.
AU - Klingelhöfer, Göstar
AU - Kusack, Alastair
AU - Madsen, Morten B.
AU - Ming, Douglas W.
AU - Morris, Richard V.
AU - Mumm, Erik
AU - Myrick, Tom
AU - Olsen, Malte
AU - Squyres, Steven W.
AU - Wilson, Jack
AU - Yen, Albert
PY - 2008/5/20
Y1 - 2008/5/20
N2 - The Rock Abrasion Tool (RAT) on board the Mars Exploration Rovers (MER) is a grinding tool designed to remove dust coatings and/or weathering rinds from rocks and expose fresh rock material. Four magnets of different strengths that are built into the structure of the RAT have been attracting substantial amounts of magnetic material during RAT activities from rocks throughout both rover missions. The RAT magnet experiment as performed on Spirit demonstrates the presence of a strongly ferrimagnetic phase in Gusev crater rocks, which based on Mössbauer and visible/near-infrared reflectance spectra is interpreted as magnetite. The amount of abraded rock material adhering to the magnets varied strongly during the mission and is correlated in a consistent way to the amount of magnetite inferred from Mössbauer spectra for the corresponding rock. The RAT magnet experiment as performed on Opportunity also indicates the presence of a strongly ferrimagnetic phase in outcrops, such as magnetite or an altered version of magnetite. However, the evidence is weaker than in the case of Spirit. According to data from the α particle X-ray spectrometer (APXS) and the Mössbauer spectrometer (MB), the Eagle crater outcrops should not contain magnetite and their magnetization should not exceed 0.03 A m2 kg-1. However, this assertion seems to be in contradiction with the results of the RAT magnet experiment. The evidence for a strongly ferrimagnetic phase at low abundance in the Meridiani outcrops is discussed.
AB - The Rock Abrasion Tool (RAT) on board the Mars Exploration Rovers (MER) is a grinding tool designed to remove dust coatings and/or weathering rinds from rocks and expose fresh rock material. Four magnets of different strengths that are built into the structure of the RAT have been attracting substantial amounts of magnetic material during RAT activities from rocks throughout both rover missions. The RAT magnet experiment as performed on Spirit demonstrates the presence of a strongly ferrimagnetic phase in Gusev crater rocks, which based on Mössbauer and visible/near-infrared reflectance spectra is interpreted as magnetite. The amount of abraded rock material adhering to the magnets varied strongly during the mission and is correlated in a consistent way to the amount of magnetite inferred from Mössbauer spectra for the corresponding rock. The RAT magnet experiment as performed on Opportunity also indicates the presence of a strongly ferrimagnetic phase in outcrops, such as magnetite or an altered version of magnetite. However, the evidence is weaker than in the case of Spirit. According to data from the α particle X-ray spectrometer (APXS) and the Mössbauer spectrometer (MB), the Eagle crater outcrops should not contain magnetite and their magnetization should not exceed 0.03 A m2 kg-1. However, this assertion seems to be in contradiction with the results of the RAT magnet experiment. The evidence for a strongly ferrimagnetic phase at low abundance in the Meridiani outcrops is discussed.
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U2 - 10.1029/2006JE002819
DO - 10.1029/2006JE002819
M3 - Article
AN - SCOPUS:48749113323
SN - 0148-0227
VL - 113
JO - Journal of Geophysical Research Atmospheres
JF - Journal of Geophysical Research Atmospheres
IS - 5
M1 - E05S90
ER -