Illumination Conditions at Mars and Their Relationships with Ice-Driven Morphology

Abstract

Geomorphology as a discipline has extended its horizons to reach other celestial bodies. Planets, dwarf planets, moons, and asteroids can be studied by applying the same geomorphological premises. Through indirect information, planetary surfaces can be interpreted in a comparative way, applying the principles of terrestrial geomorphology to other planets but taking into account the physical properties of each planet. Nevertheless, some caution must be taken since a similar landform can have different origins on different planets. Mars has several geomorphic features that might be related with seasonal changes and liquid water/ice interaction. In this chapter, we make use of the MarsLux code to investigate changes in illumination conditions and relate the illumination and insolation maps with different landforms. For example, we could relate the resulting maps with cycles of freezing and thawing on the Martian surface. Also, by generating maps of illumination over one Martian year, we can relate the location of certain features with specific areas that receive an anomalous amount of solar energy. We present a tool that can connect an illumination analysis, from orbital parameters, with changes in insolation over geologically recent times and geomorphological evidence that points to the presence of subsurface ice, or alternatively to the thermal weathering of rocks.