Jarosite and Hematite at Meridiani Planum from Opportunity's Mössbauer Spectrometer

• Published in: Science (American Association for the Advancement of Science) 2004-12, Vol.306 (5702), p.1740-1745
• Main Authors: Klingelhöfer, G., Morris, R. V., Bernhardt, B., Schröder, C., Rodionov, D. S., de Souza, P. A., Yen, A., Gellert, R., Evlanov, E. N., Zubkov, B., Foh, J., Bonnes, U., Kankeleit, E., Gütlich, P., Ming, D. W., Renz, F., Wdowiak, T., Squyres, S. W., Arvidson, R. E.
• Format: Article
• Language: English
• Subjects: Basaltic soils; Climate; Composition; Data Analysis; Discovery and exploration; Extraterrestrial Environment; Ferric Compounds; Fractions; Geologic Sediments; Hematite; Impact craters; Iron Compounds; Least Squares Statistics; Magnesium Compounds; Mars; Mars (Planet); Mars probes; Mineralogy; Minerals; Mössbauer spectroscopy; Olivine; Opportunities; Outcrops; Pyroxenes; Research Articles and Reports; Rocks; Scientific imaging; Sextets; Silicates; Soil mineralogy; Soils; Space exploration; Spacecraft; Spectroscopy, Mossbauer; Sulfates; Surface (Geology); Water
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1104653

Mössbauer spectra measured by the Opportunity rover revealed four mineralogical components in Meridiani Planum at Eagle crater: jarosite- and hematite-rich outcrop, hematite-rich soil, olivine-bearing basaltic soil, and a pyroxene-bearing basaltic rock (Bounce rock). Spherules, interpreted to be concretions, are hematiterich and dispersed throughout the outcrop. Hematitic soils both within and outside Eagle crater are dominated by spherules and their fragments. Olivine-bearing basaltic soil is present throughout the region. Bounce rock is probably an impact erratic. Because jarosite is a hydroxide sulfate mineral, its presence at Meridiani Planum is mineralogical evidence for aqueous processes on Mars, probably under acid-sulfate conditions.