- © 2016 Mineralogical Society of America
Water and/or hydroxyl (OH)-bearing minerals are valuable petrologic indicators of past conditions on Mars. In addition to indicating the presence of some form of water on Mars in the past, many of them form only under restricted conditions. Similarly, several of them are unstable or metastable under current Mars surface conditions. Thus, identifying specific types of water-bearing minerals that are present on Mars can provide insights into past conditions.
While phyllosilicates were the first water-bearing minerals inferred to be present on Mars from analysis of Earth-based telescopic spectra (McCord et al. 1982), it took recent spacecraft missions to enable mapping the global distribution and determining the types of specific species that are present on the surface and their geological context.
Even at coarse spatial scales of a few kilometers, several regions on Mars whose surfaces were spectrally dominated by water-bearing minerals were identified by their spectral reflectance signatures [Observatoire pour la Minéralogie, l’Eau, les Glaces, et l’Activité (OMEGA) aboard the European Space Agency Mars Express …