The Mars Science Laboratory rover, Curiosity, has explored the northern margin of Mount Sharp for 4451 Martian sols. During this time, the mission scientists have gathered compelling evidence that shortly after crater formation, a habitable environment existed within it.
The rocks that form lower Mount Sharp preserve a record of persistent lakes fed by fluvial systems originating from the crater rim. As the rivers entered the lake, they released plumes of sediment and assorted nutrients into the water column to be distributed across the lakebed — recorded as the Murray formation. Geochemical and mineralogical assessments indicate that environmental conditions preserved in these layered rocks would have sustained life, if it were present.
On Sol 3047, Curiosity made a sharp right turn after crossing the phyllosilicate unit, to drive up into the orbitally-defined sulphate-bearing unit. From this point, Curiosity witnessed distinct changes in the stratigraphy, recording a progressive drying of the ancient environment. The rover identified a gradual change from humid conditions containing a record of perennial lakes, to isolated ephemeral lakes, and onto desolate deserts. During this ascent, interstratification of aeolian strata became increasingly common, including sand sheets, dune strata and deflation scours. However, despite this general aridification, the succession was occasionally punctuated by episodes of abundant water: the Amapari ripple bed for example, records a brief shallow lake: a veritable oasis, free of ice.
This presentation will showcase the changes recorded by the rover during its ascent of Mount Sharp, to understand how habitability was impacted by climate change.
Speaker biography:
Steven Banham is a UK Space Agency Research Fellow who is a collaborator on the NASA-JPL Mars Science Laboratory (MSL) and the ESA ExoMars mission. Graduating from Keele University with an M.Geoscience degree, he moved to the University of Leeds to research Fluvial Systems in dryland environments, gaining his PhD in 2014. He then worked for the British Geological Survey as a Petroleum Basin Analysist working on the UK continental shelf. In 2015, he moved to Imperial College to collaborate on MSL as a sedimentary geologist, becoming a research fellow in 2018.
On MSL, Steven works on the MASTCAM instrument as PUL-1, and a Surface Properties Scientist. He has authored five papers on the ancient surface environment, and the burial history of sediments in Gale crater. His has contributed to over 20 publications of the habitable environment within Gale. On ExoMars, he is a PanCam instrument collaborator and is a Geology Working Group lead. He is involved in training and preparation of mission scientists for the arrival of ExoMars at Oxia Planum.