International audienceMars Express remains one of ESA’s most scientifically productive missions whose publication record nowexceeds 1000 papers. Characterization of geological processes on a local-to-regional scale by HRSC, OMEGAand partner experiments on NASA spacecraft has allowed constraining land-forming processes in space and time.Recent results suggest episodic geological activity as well as the presence of large bodies of liquid water in severalprovinces (e.g. Eridania Planum, Terra Chimeria) in the early and middle Amazonian epoch and formation ofvast sedimentary plains north of the Hellas basin. Mars Express observations and experimental teams providedan essential contribution to the selection of the Mars-2020 ...