DIX Planetary Science Seminar

Mars, often described as a frozen desert, is an active planet shaped today by CO₂ and water frosts. Yet, abundant evidence of ancient glaciers at the surface and buried ice deposits in the mid-latitudes indicates that Mars experienced significantly different climatic conditions in its recent past.

Climate models suggest that periods of high obliquity caused the atmosphere to become much wetter, leading to the formation of widespread snowfall and extensive glaciers at mid-latitudes. As obliquity decreased and the climate became drier, these glaciers sublimated and became buried beneath the surface. Remarkably, such subsurface ice can persist for millions of years, preserving a valuable record of past Martian climates. Understanding this buried ice is therefore essential to reconstructing the many climatic "faces" Mars has exhibited through time.

In this presentation, I review how our knowledge of Mars' recent climate has evolved alongside advances in climate modeling. I show that current models still struggle to reproduce the observed distribution, depth, and apparent youth of many glacial features. I then highlight the crucial role of water cloud radiative effects and the significant challenges they pose for models. Finally, I present a new perspective on Mars' recent climates.