The Perseverance rover (Mars 2020 mission, NASA) landed in Jezero crater, Mars, the site of an ancient lake, on February 2021. The main science objectives of the mission are the characterization of past environments, the search for preserved biosignatures and the collection of samples to be returned to Earth by the MSR mission (Mars Sample Return). The payload of Perseverance includes the SuperCam instrument, which combines various remote-sensing techniques to investigate the elemental and mineralogical composition of rocks and soils. In particular, the near-infrared reflectance spectrometer (IRS), which covers the 1.3–2.6 µm range, allows for the identification of a wide variety of mineral phases, and especially hydrated ones.
From a technical point of view, IRS is a miniaturized spectrometer based on AOTF (Acousto-Optic Tunable Filter) technology. This optical element is the cornerstone of the IRS' performance and its flight calibration will be presented in this seminar. Then, we will give an overview of the minerals detected by the IRS during the first year of the mission and the implications on the geological history of the crater floor in terms of igneous and alteration processes. As the IRS is the first near-infrared spectrometer operating directly on the surface of Mars, we will also discuss how these results bring insights into the orbital studies using near-infrared data.