Windows of Mars: Impact Craters Along the Martian Dichotomy as Markers for Planetary Evolution

Sammanfattning

When an impact excavates and modifies the Martian surface, by bringing deeper lying material to the surface, it opens a window into past geology. Trying to understand surface properties on Mars and how target material behaves during impact requires a multi-view approach. Previous research has focused mainly on ejecta emplacement and morphologies as a proxy for surface properties. However, interior morphological structures, such as central uplifts and terraces of complex craters might hold important information about the target material as well. With the use of JMARS and HiRISE imaging, such structures have been analysed in this work. The focus area lies around the Martian dichotomy, a crustal boundary separating old, heavily cratered highlands in the south from smooth lowlands composed of younger deposits in the north. The area of interest ranges from approximately 58°N to 4°N and 58°E to 40°E but future studies may further investigate the same area and other areas with similar characteristics. Three impact craters have been chosen for investigation: (1) the Quenisset crater, located in the Southern highlands, (2) the Moreux crater along the Martian dichotomy and (3) an unnamed crater in the Northern lowlands. All craters show structures and features formed by water, highlighting the importance of understanding how water-rich material behaves during impact. Another marker for surface properties is the size difference of craters which might reveal what the target material is made off as it varies between e.g. sedimentary deposits and crystalline bedrock.