B. C. Clark

A native sulfur deposit in Gale crater, Mars

Scott J. V. VanBommel, Jeff A. Berger, P. L. King, W. E. Dietrich et autres

Martian rocks are known to contain sulfur-bearing species, including sulfates and sulfides. These compounds record a sulfur cycle that operated over the geological evolution of Mars. We used the Curiosity rover to investigate a deposit of light-toned stones in Gediz Vallis within …

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The Possible Aqueous Origins of Manganese Alteration Minerals in the Máaz Formation of Jezero Crater

Kimberly P. Sinclair, B. C. Clark, Michael W. M. Jones, David C. Catling et autres

Home to a lake around 4 billion years ago, Jezero Crater is a unique location to study the interplay between igneous processes and aqueous alteration on ancient Mars. The Máaz formation, rich in basaltic rock, is the highest stratigraphic unit on the …

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Viking Science

B. C. Clark

The Viking missions hosted identical payloads on each of two orbiters and landers. All four missions far exceeded their pre-planned operating times and science objectives, with all but one of the 40 science experiments operating fully successfully. Six experiments on each lander …

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Mineralogically Diverse and Salt‐Rich Regolith in Jezero Crater Characterized Using X‐Ray Spectroscopy

Andrew O. Shumway, T. V. Kizovski, David C. Catling, Scott J. V. VanBommel et autres

Abstract The Planetary Instrument for X‐ray Lithochemistry (PIXL) onboard the Perseverance rover has characterized the composition of Martian regolith at a scale of hundreds of microns using micro‐focus X‐ray fluorescence spectroscopy. PIXL data reveal a diverse population of regolith grains with distinct …

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The effects of brines relevant to Mars and the ocean worlds on bacterial growth reflect salt-specific responses across water activity

M. D. Joad, Hadi H Zayed, Ammar Mahdi, Fei Chen et autres

Abstract Freezing point depression due to high salt concentration is crucial for liquid water to exist on cold worlds, expanding special regions where habitats are plausible. Determination of the growth tolerances of terrestrial microbes in analog systems impacts planetary protection protocols aimed …

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In situ evidence for serpentinization within the Máaz formation, Jezero crater, Mars

Nicholas J. Tosca, Michael M. Tice, J. A. Hurowitz, David A. K. Pedersen et autres

As both a source of atmospheric H 2 and a sink for liquid water, the serpentinization of olivine-bearing rocks is widely thought to have influenced the long-term evolution of the early martian atmosphere and hydrosphere. However, the mechanisms, timing, and global importance …

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In situ crystallographic mapping constrains sulfate precipitation and timing in Jezero crater, Mars

Michael W. Jones, David Timothy Flannery, J. A. Hurowitz, Michael M. Tice et autres

Late-stage Ca-sulfate-filled fractures are common on Mars. Notably, the Shenandoah formation in the western edge of Jezero crater preserves a variety of Ca-sulfate minerals in the fine-grained siliciclastic rocks explored by the Perseverance rover. However, the depositional environment and timing of the …

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Collection and In Situ Analyses of Regolith Samples by the Mars 2020 Rover: Implications for Their Formation and Alteration History

Elisabeth M. Hausrath, ROBERT J. SULLIVAN, Yulia S. GOREVA, María‐Paz Zorzano et autres

Abstract The Perseverance rover has sampled mm‐size lithic fragments containing olivine likely from at least two source regions from the surface of an inactive megaripple surface, and fine‐grained material from the surface and to a depth of ∼4–6 cm. Some of the …

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Diverse and highly differentiated lava suite in Jezero crater, Mars: Constraints on intracrustal magmatism revealed by Mars 2020 PIXL

M. E. Schmidt, T. V. Kizovski, Yang Liu, Juan David Hernández‐Montenegro et autres

The Jezero crater floor features a suite of related, iron-rich lavas that were examined and sampled by the Mars 2020 rover Perseverance, and whose textures, minerals, and compositions were characterized by the Planetary Instrument for X-ray Lithochemistry (PIXL). This suite, known as …

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Attribute recognition: A new method for grouping planetary images by visual characteristics, using the example of Mn-rich rocks in the floor of Gale crater, Mars

Ari Essunfeld, Jade M. Comellas, P. J. Gasda, Dorothea Delapp et autres

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Adaptive sampling with PIXL on the Mars Perseverance rover

Peter R. Lawson, T. V. Kizovski, Michael M. Tice, B. C. Clark et autres

Planetary rovers can use onboard data analysis to adapt their measurement plan on the fly, improving the science value of data collected between commands from Earth. This paper describes the implementation of an adaptive sampling algorithm used by PIXL, the X-ray fluorescence …

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Fe-phosphates in Jezero Crater: Chemical, Structural, and Spectral Evidence for an Ancient Habitable Environment on Mars

T. V. Kizovski, M. E. Schmidt, L. P. O’Neil, Michael W. Jones et autres

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