The Mars Science Laboratory rover, Curiosity, landed on the floor of Gale crater, Mars, on August 5, 2012. In the last 5.5 years, Curiosity has traversed over 11 miles (18 km) to explore 1,200 ft (370 m) of basin-fill stratigraphy exposed as layered sediments preserved around the craters' central peak, a 16,000 ft (5 km) tall stack of sediments dubbed Mount Sharp.

Along this traverse, Curiosity has collected tens of thousands of images of the Martian surface in addition to 500,000 laser shot-based chemistry analyses, 600 bulk chemistry analyses. The lab rover has 15 drilled samples observed with both a mass spectrometer and an x-ray diffractometer, sending the data back to Earth on a daily basis. The instrument suite onboard Curiosity has enabled the highest resolution ever achieved in in-situ imaging of planetary surface samples, the first age date on another planet, ongoing chemostratigraphy based on multiple scales of compositional measurements, and ten robotic Martian selfies.

Far beyond the numbers, Curiosity's findings have revolutionized our understanding of Mars. Whereas it was once thought that Mars may have only had intermittent short-lived periods of relatively clement atmospheric conditions, Curiosity has investigated over 300 m of mudstone deposited in a lake of liquid water that would have potentially had habitable conditions for life ∼3.5 billion years ago that seems to have been sustained for at least 3 million years. These lake (and associated fluvial and deltaic) sediments underwent multiple episodes of diagenesis suggesting groundwater was present for long durations. The presence of cemented sedimentary strata that overlie angular unconformities show that significant fractions of the 152-km-diameter crater were filled with water-cemented sediments and then largely evacuated by wind at least twice prior to ∼3 billion years ago.

Curiosity has also shown that early Mars had more igneous diversity than previously predicted, eolian bedforms with distinct wavelengths formed under different atmospheric conditions and today has active sand dunes and seasonal variations in atmospheric methane.

Professor Siebach will present the developing story of the history of the Gale crater basin and the basin analysis work she has done to understand source-to-sink processes by separating chemical effects from source rock diversity, sediment transport, and diagenetic influences for multiple sedimentary cycles.