Advances in Earth Science ›› 2010, Vol. 25 ›› Issue (7): 691-697. doi: 10.11867/j.issn.1001-8166.2010.07.0691
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Zhu Minqiang, Zhou Wanpeng, Hu Quanyi
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Zhu Minqiang, Zhou Wanpeng, Hu Quanyi. Progresses in OMEGA/Mars Express Detecting Minerals on Mars[J]. Advances in Earth Science, 2010, 25(7): 691-697.
The paper mainly introduces the features of OMEGA/Mars Express instrument and acquired data, the atmospheric correction methods, and recent progresses of mineral detection. Empirical Transmission Functions (ETF) is the relative effective atmospheric correction method up to now. The OMEGA data have successfully revealed the diversity and complex of Mars surface minerals and composition. The hydrated phyllosilicates, a family of aqueous alteration products, such as nontronite, chlorite and montmorillonite, are detected by OMEGA. These minerals are mainly associated with Noachian outcrops, which are consistent with an early active hydrological system, sustaining the long-term contact of igneous minerals with liquid water. The hydrated sulfates, such as gypsum, kieserite and polyhydrated sulfates, are identified on light-toned layered terrains. The existence of these minerals means that there have evaporates deposits on Mars which are related to water processes. Anhydrous ferric oxides formed in a slow superficial weathering are distributed in lowland over the northern hemisphere, without liquid water playing a major role across the planet. OMEGA can identify pyroxene and olivine. It discriminates between the high-calcium pyroxenes and low-calcium pyroxenes. The high-calcium pyroxenes dominate in low-albedo volcanic regions of Hesperian age, dark sand and crater ejecta. The low-calcium pyroxenes occur as moderate to bright outcrops in older, Noachian terrains. OMEGA can also discriminate the H2O ice and CO2 ice in varied high-albedo polar icecap area. The H2O ice absorption features are major in the 1.08 m, 1.25 m, 1.51 m and 2.0m. The H2O ice absorption depth increases with the ice grain size. The CO2 ice can be identified by 1.43 m, 2.0 m and 2.6m absorption features.