The Geology of Mars as Seen by MRO's HiRISE

By September 2007 the High Resolution Imaging Science Experiment (HiRISE) had acquired more than 3,000 images of Mars at resolutions as high as 25 cm/pixel in the 3 PM mapping orbit of Mars Reconnaissance Orbiter, covering about 0.2 percent of the surface. These images are helping to address a broad range of science issues, as presented in dozens of abstracts to this conference. In this talk I will focus on several topics. (1) The color data is proving quite valuable to reduce the ambiguities of B&W images; to correlate deposits and better define the stratigraphy; and to extend mineral identifications to the scale of outcrops. (2) The nature of the Martian highlands is being revealed, with the identification of megabreccia, hydrous minerals (by OMEGA and CRISM spectrometers), and the detailed nature of the layered or massive stratigraphy where exposed in cross- section. (3) There is new evidence for the roles of water in the most recent large (at least 1 km diameter) impact craters, which may have implications for the altered mineralogy of the ancient crust. (4) New observations and measurements are leading to improved understanding of slope processes such as gullies, creep, and mass wasting. We are producing meter-scale digital elevation models to test high-priority science questions.