Chemistry of Rocks and Soils at Meridiani Planum from the Alpha Particle X-ray Spectrometer

• Published in: Science (American Association for the Advancement of Science) 2004-12, Vol.306 (5702), p.1746-1749
• Main Authors: Rieder, R., Gellert, R., Anderson, R. C., Brückner, J., Clark, B. C., Dreibus, G., Economou, T., Klingelhöfer, G., Lugmair, G. W., Ming, D. W., Squyres, S. W., d'Uston, C., Wänke, H., Yen, A., Zipfel, J.
• Format: Article
• Language: English
• Subjects: Alpha Particles; Basaltic soils; Bromine; Chemical composition; Chlorine; Composition; Discovery and exploration; Elements; Extraterrestrial Environment; Ferric Compounds; Geochemistry; Geologic Sediments; Hematite; Impact craters; Iron; Magnesium; Mars; Mars (Planet); Mineralogy; Minerals; Opportunities; Organic Chemistry; Outcrops; Research Articles and Reports; Rocks; Salts; Scientific imaging; Silicates; Soil analysis; Soil chemistry; Soil composition; Soils; Space exploration; Spacecraft; Spectrometry, X-Ray Emission; Sulfates; Sulfur; Surface (Geology); Water
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1104358

The Alpha Particle X-ray Spectrometer on the Opportunity rover determined major and minor elements of soils and rocks in Meridiani Planum. Chemical compositions differentiate between basaltic rocks, evaporite-rich rocks, basaltic soils, and hematite-rich soils. Although soils are compositionally similar to those at previous landing sites, differences in iron and some minor element concentrations signify the addition of local components. Rocky outcrops are rich in sulfur and variably enriched in bromine relative to chlorine. The interaction with water in the past is indicated by the chemical features in rocks and soils at this site.