Samples Collected From the Floor of Jezero Crater With the Mars 2020 Perseverance Rover

• Published in: Journal of geophysical research. Planets Vol. 128; no. 6
• Main Authors: Simon, J. I., Hickman‐Lewis, K., Cohen, B. A., Mayhew, L. E., Shuster, D. L., Debaille, V., Hausrath, E. M., Weiss, B. P., Bosak, T., Zorzano, M.‐P., Amundsen, H. E. F., Beegle, L. W., Bell, J. F., Benison, K. C., Berger, E. L., Beyssac, O., Brown, A. J., Calef, F., Casademont, T. M., Clark, B., Clavé, E., Crumpler, L., Czaja, A. D., Fairén, A. G., Farley, K. A., Flannery, D. T., Fornaro, T., Forni, O., Gómez, F., Goreva, Y., Gorin, A., Hand, K. P., Hamran, S.‐E., Henneke, J., Herd, C. D. K., Horgan, B. H. N., Johnson, J. R., Joseph, J., Kronyak, R. E., Madariaga, J. M., Maki, J. N., Mandon, L., McCubbin, F. M., McLennan, S. M., Moeller, R. C., Newman, C. E., Núñez, J. I., Pascuzzo, A. C., Pedersen, D. A., Poggiali, G., Pinet, P., Quantin‐Nataf, C., Rice, M., Rice, J. W., Royer, C., Schmidt, M., Sephton, M., Sharma, S., Siljeström, S., Stack, K. M., Steele, A., Sun, V. Z., Udry, A., VanBommel, S., Wadhwa, M., Wiens, R. C., Williams, A. J., Williford, K. H.
• Format: Journal Article
• Language: English
• Published: 01.06.2023
• Subjects: Jezero Crater; Mars 2020; Mars sample return; rock core
• ISSN: 2169-9097; 2169-9100
• DOI: 10.1029/2022JE007474

The first samples collected by the Mars 2020 mission represent units exposed on the Jezero Crater floor, from the potentially oldest Séítah formation outcrops to the potentially youngest rocks of the heavily cratered Máaz formation. Surface investigations reveal landscape‐to‐microscopic textural, mineralogical, and geochemical evidence for igneous lithologies, some possibly emplaced as lava flows. The samples contain major rock‐forming minerals such as pyroxene, olivine, and feldspar, accessory minerals including oxides and phosphates, and evidence for various degrees of aqueous activity in the form of water‐soluble salt, carbonate, sulfate, iron oxide, and iron silicate minerals. Following sample return, the compositions and ages of these variably altered igneous rocks are expected to reveal the geophysical and geochemical nature of the planet's interior at the time of emplacement, characterize martian magmatism, and place timing constraints on geologic processes, both in Jezero Crater and more widely on Mars. Petrographic observations and geochemical analyses, coupled with geochronology of secondary minerals, can also reveal the timing of aqueous activity as well as constrain the chemical and physical conditions of the environments in which these minerals precipitated, and the nature and composition of organic compounds preserved in association with these phases. Returned samples from these units will help constrain the crater chronology of Mars and the global evolution of the planet's interior, for understanding the processes that formed Jezero Crater floor units, and for constraining the style and duration of aqueous activity in Jezero Crater, past habitability, and cycling of organic elements in Jezero Crater. Plain Language Summary Here we provide a narrative of sample collection and associated in situ rover observations for the rocks collected by the Perseverance rover to provide a preliminary description of the first samples of the Mars 2020 mission. These rocks collected in Jezero Crater represent the first samples from Mars with a known geologic context, the first collected with the potential to be returned to Earth for laboratory analysis, and the first cores from rock outcrops on another planet. Remote and proximal analyses indicate that all crater floor outcrops investigated are igneous in origin. Laboratory analyses of these rocks will be useful to study the planet's interior at the time of emplacement, characterize martian magmatism, and place timing constraints on geologic processes, both in Jezero Crater and more widely on Mars. All collected rocks have interacted with water and contain secondary geochemical and mineralogical evidence that can be used to understand aqueous environments in the crater and the potential conditions of habitability for ancient life on Mars. Key Points Nine samples, consisting of four pairs of rock cores and a tube of atmospheric gas, were collected from the floor of Jezero Crater, Mars In situ observations of crater floor outcrops, used as proxies for the samples, reveal aqueously altered igneous lithologies Perseverance will leave one sample from each pair at the Three Forks depot and retain a second to be cached with future samples