Modeling the past climates of planet Mars to understand its geology, its habitability and its evolution

ended

Over the past decades, the robotic exploration of the planet Mars has produced a wealth of geological observations. They show that Mars has not always been the desert planet of today. It has seen eras conducive to rivers and lakes, ice ages, and even periods with a collapsed atmosphere. These different epochs are the reason why Mars remains the objective of space agencies, as they evoke the possibility of past habitability and spectacular climate changes. Yet, in spite of all the data, the climatic processes that have shaped Mars’ surface through time remain largely unknown. What happened on Mars? Was the Red Planet suitable for life? What explains its evolution? The objective of this project is to develop numerical models to simulate the past environments of Mars.A completely new “Mars Evolution Model” will be created by asynchronously coupling hydrology, glacial flows and ground ice models with a new generation 3D Global Climate Model (GCM). This GCM will be derived from the one that we have previously designed to simulate present day Mars. We will radically update it using new technologies to represent the details of the surface as well as all the processes that affected Mars when its environment evolved because of the oscillations of its orbit and obliquity, during changes in the atmospheric composition, or through events like meteoritic impacts or volcanic eruptions. Notably, we will highlight the last ten millions years that have been recorded in the polar layered deposits, whose formation will be simulated for the first time realistically. These new tools will address numerous enigmas found in Mars sciences. They will also offer a new platform to study specific processes such as the atmospheric escape through time or the chemical alteration of the soil. Furthermore, the project will test our capacity to model planetary environments and climate changes, as well as provide lessons on the evolution of terrestrial planets and the possibility of life elsewhere.