Unravelling the secrets of Mars' polar caps
Lead Research Organisation:
The Open University
Department Name: Faculty of Sci, Tech, Eng & Maths (STEM)
Abstract
Mars' polar caps are very different in composition and morphology, although solar energy density averaged over a year is the same at both poles. While water ice deposits dominate Mars' North Pole, its south pole has a CO2 ice cap.
The polar ice caps exhibit a remarkable complexity, and some carbon dioxide features of Mars' south polar cap (e.g. Malin et al., 2002, Titus et al., 2004) point at as yet poorly understood physical processes resulting in enigmatic surface features that have been dubbed, e.g., as "spiders" (Piqueux et al., 2003) or "swiss cheese" terrain (Thomas et al., 2000). What is clear is that atmospheric dust plays a central role in the dynamics of the Martian ice caps. The temperature of the southern polar cap is controlled by its albedo, which is in turn controlled by dust on its surface (Paige and Ingersoll, 1985). Strangely, the albedo increases during the summer. Several self-cleansing mechanisms have been proposed for this phenomenon but none has been successfully simulated in the laboratory.
In this project, we plan to investigate the dynamics of Mars' southern polar cap using the planetary ices simulation facility at The Open University's Department of Physical Sciences. In this unique facility, which played a key role in understanding the processes that lead to the formation of Martian 'spiders' (Kaufmann & Hagermann, 2016), we can recreate the conditions on Mars' surface and observe the behaviour of CO2 ice under Martian conditions. We will investigate the dynamics of an ice sample in a series of Martian artificial day/night cycles, simulating frost precipitation, dust deposition, surface and subsurface melting in situ. What we aim to understand is the physical processes that lead to layering, texture and morphology changes. The outcomes of the simulations will be used to construct a physical model of Mars' south polar transient ice cap. We will then build a thermal mathematical model which can numerically simulate the processes that lead to the albedo changes observed in nature using the COMSOL Multiphysics software package.
The polar ice caps exhibit a remarkable complexity, and some carbon dioxide features of Mars' south polar cap (e.g. Malin et al., 2002, Titus et al., 2004) point at as yet poorly understood physical processes resulting in enigmatic surface features that have been dubbed, e.g., as "spiders" (Piqueux et al., 2003) or "swiss cheese" terrain (Thomas et al., 2000). What is clear is that atmospheric dust plays a central role in the dynamics of the Martian ice caps. The temperature of the southern polar cap is controlled by its albedo, which is in turn controlled by dust on its surface (Paige and Ingersoll, 1985). Strangely, the albedo increases during the summer. Several self-cleansing mechanisms have been proposed for this phenomenon but none has been successfully simulated in the laboratory.
In this project, we plan to investigate the dynamics of Mars' southern polar cap using the planetary ices simulation facility at The Open University's Department of Physical Sciences. In this unique facility, which played a key role in understanding the processes that lead to the formation of Martian 'spiders' (Kaufmann & Hagermann, 2016), we can recreate the conditions on Mars' surface and observe the behaviour of CO2 ice under Martian conditions. We will investigate the dynamics of an ice sample in a series of Martian artificial day/night cycles, simulating frost precipitation, dust deposition, surface and subsurface melting in situ. What we aim to understand is the physical processes that lead to layering, texture and morphology changes. The outcomes of the simulations will be used to construct a physical model of Mars' south polar transient ice cap. We will then build a thermal mathematical model which can numerically simulate the processes that lead to the albedo changes observed in nature using the COMSOL Multiphysics software package.