Understanding the alteration history of Mars is fundamental to reconstruct its environmental evolution and assessing its past habitability. The Martian surface preserves a complex record of interactions between rocks, water, atmosphere, and climate, expressed through alteration minerals, sedimentary deposits, and geomorphological features. Together, these records provide key constraints on the occurrence, persistence, and chemistry of liquid water, and on the conditions under which potentially habitable environments developed and evolved.

Recent observations from orbital and rover missions have revealed an increasingly complex record of Martian alteration, challenging simplified models of a single, globally coherent alteration history. The diversity and distribution of alteration products instead point to a dynamic interplay between aqueous processes, climate, geology, and surface–atmosphere interactions. Integrating mineralogical, geochemical, stratigraphic, and geomorphological perspectives is therefore essential to unravel the timing and diversity of these processes.

This session welcomes studies of Martian alteration processes (e.g., surface weathering, groundwater circulation, and diagenesis), and their implications for climate and habitability. Contributions using orbital, in situ, experimental, or modelling approaches are particularly encouraged. By combining complementary perspectives, the session will explore how Mars' geological record can constrain its environmental evolution and the nature and persistence of past habitable environments.