Spectral Variability of Rocks and Soils on the Jezero Crater Floor: A Summary of Multispectral Observations From Perseverance's Mastcam-Z Instrument

NASA's Mars-2020 Perseverance rover spent its first year in Jezero crater studying the mafic lava flows of the Máaz formation and the ultramafic cumulates of the Séítah formation, both of which have undergone minor alteration and are variably covered by coatings, dust, and/or soil deposits. Documenting the rock and soil characteristics across the crater floor is critical for establishing the geologic context of Perseverance's cached samples—which will eventually be returned to Earth—and for interpreting the deposition and modification of the Máaz and Séítah formations. Mastcam-Z, a pair of multispectral, stereoscopic zoom-lens cameras, provides broadband red/green/blue and narrowband visible to near-infrared images (VNIR, 440–1,020 nm). From multispectral observations from sols 0 to 380, we compiled a database of ∼2,400 representative Mastcam-Z spectra. We analyzed principal components, spectral parameters, and laboratory spectra of pure minerals and natural rock surfaces to interpret the spectral diversity of rocks and soils. We define eight spectral classes of rocks: Dusty, Hematite-like, Coated, Low-Ca Pyroxene-like, Olivine-like, Weathered Olivine-like, Fe-rich Pyroxene-like, and Dark Oxide-like. The variability of soil spectra in the Jezero crater floor is controlled primarily by the amount of dust and indicates a largely consistent soil mineralogy across the traverse, with the exception of the area disturbed by the landing event. In comparison to rock spectra from the Curiosity rover's Mastcam instrument in Gale crater, rocks on the Jezero crater floor are generally less spectrally diverse, but the Olivine-like rocks within the Séítah formation represent a new spectral rock class in Mars surface exploration.