Quantification of Surface Roughness of Lava Flows on Mars

Volcanism has played a significant role throughout Mars’ geologic history. Extensive lava flows are widely spread across Mars’ equatorial region, shaping the surface in a very distinct way. In radar images (at the decimeter scale), these flows are bright, which is a typical characteristic of extremely rough, blocky lavas flows seen on Earth. Although the source of the extreme roughness of Martian lava flows is unknown, their surface roughness parameters can be constrained to 1) gain information about Mars’ interior processes, 2) find appropriate analogues on other planetary bodies, and 3) ideally infer the emplacement style of such lavas. Here, we utilized very detailed high-resolution images of Mars to measure the surface roughness parameters of Martian lava flows at a scale never before examined on the Martian surface (meter scale). Our results determined that at the meter scale, Martian lava flows are smoother than blocky flows seen on Earth, somewhat similar to pahoehoe and rubbly flows seen in Hawaii and Iceland (which are smoother at the decimeter scale), and similar to young lunar lava flows (also smoother at the decimeter scale). The differences observed in the surface roughness of Martian lava flows at the decimeter and meter scales compared to analogue lava flows on Earth and the Moon might be the result of: 1) the differences in the emplacement style of the lava flows, 2) the differences in post-emplacement modification processes on the surface of the lava flows, and/or 3) the limitations of the technique used to characterize the lava flows

Aqueous alteration processes in Jezero crater, Mars—implications for organic geochemistry

The Perseverance rover landed in Jezero crater, Mars, in February 2021. We used the Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) instrument to perform deep-ultraviolet Raman and fluorescence spectroscopy of three rocks within the crater. We identify evidence for two distinct ancient aqueous environments at different times. Reactions with liquid water formed carbonates in an olivine-rich igneous rock. A sulfate-perchlorate mixture is present in the rocks, which probably formed by later modifications of the rocks by brine. Fluorescence signatures consistent with aromatic organic compounds occur throughout these rocks and are preserved in minerals related to both aqueous environments

Near-Earth Objects

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