Astrogeology Science Center

Publications

Filter Total Items: 804
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Year Published: 2020

The chemostratigraphy of the Murray formation and role of diagenesis at Vera Rubin ridge in Gale crater, Mars, as observed by the ChemCam instrument

Geochemical results are presented from Curiosity’s exploration of the Vera Rubin ridge (VRR), in addition to the full chemostratigraphy of the predominantly lacustrine mudstone Murray formation up to and including VRR. VRR is a prominent ridge flanking Aeolis Mons (informally Mt. Sharp), the central mound in Gale crater, Mars, and was a key area...

Frydenvang, Jens; Mangold, Nicholas; Wiens, Roger C.; Fraeman, Abigail A.; Edgar, Lauren A.; Fedo, Christopher M.; L'Haridon, Jonas; Bedford, Candice C.; Gupta, Sanjeev; Grotzinger, John P.; Bridges, Jon C.; Clark, Ben C.; Rampe, Elizabeth B.; Gasnaut, Olivier; Maurice, Sylvestre; Gasda, Patrick J.; Lanza, Nina L.; Olilla, Ann M.; Meslin, Pierre-Yves; Payre, Valerie; Calef, Fred J.; Salvatore, Mark R; House, Christopher H

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Year Published: 2020

Conceptual model for the removal of cold-trapped H2O ice on the Mars northern seasonal springtime polar cap

The transport of H2O ice along the retreating north polar seasonal CO2 ice cap has previously been modeled and observed. Spectral observations show that H2O ice forms on the interior of the seasonal cap, while thermal observations show these regions to be consistent with CO2 ice. Prior to the sublimation of the seasonal CO2, the observed...

Titus, Timothy N.; Williams, Kaj; Cushing, Glen E.

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Year Published: 2020

Disk-integrated thermal properties of Ceres measured at the millimeter wavelengths

We observed Ceres at three epochs in 2015 November and 2017 September and October with Atacama Large Millimeter/submillimeter Array (ALMA) 12 m array and in 2017 October with the ALMA Compact Array (ACA), all at ~265 GHz continuum (wavelengths of ~1.1 mm) to map the temperatures of Ceres over a full rotation at each epoch. We also used 2017...

Li, Jian-Yang; Moullet, Arielle; Titus, Timothy N.; Hsieh, Henry H.; Sykes, Mark V.

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Year Published: 2019

Walk in the footsteps of the Apollo astronauts: A field guide to northern Arizona astronaut training sites

Every astronaut who walked on the Moon trained in Flagstaff, AZ. In the early 1960s, scientists at the newly formed United States Geological Survey (USGS) Branch of Astrogeology led this training, teaching geologic principals and field techniques to the astronaut crews. USGS scientists and engineers also developed and tested scientific...

Vaughan, R. Greg; Schindler, Kevin; Stevens, Jeanne; Hough, Ian

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Year Published: 2019

Report from the Ice and Climate Evolution Science Analysis group (ICE-SAG)

This document is the final report of the Ice and Climate Evolution Science Analysis Group (ICESAG) that was formed by the Mars Exploration Program Analysis Group (MEPAG) as part of its preparations for the upcoming NASA Planetary Science Decadal Survey for 2023 through 2032 (see §1). Through telecons, one face-to-face meeting, and discussions with...

Putzig, Than; Diniega, Serina; Dundas, Colin M.; Titus, Timothy N.

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Year Published: 2019

Active boulder movement at high Martian latitudes

Lobate stony landforms occur on steep slopes at high latitudes on Mars. We demonstrate active boulder movement at seven such sites. Sub-meter-scale boulders frequently move distances of a few meters. The movement is concentrated in the vicinity of the lobate landforms but also occurs on other slopes. This provides evidence for a new, common style...

Dundas, Colin M.; Mellon, Michael T.; Conway, Susan J.; Gastineau, Renaldo

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Year Published: 2019

Formation of pedestalled, relict lakes on the McMurdo Ice Shelf, Antarctica

Surface debris covers much of the western portion of the McMurdo Ice Shelf and has a strong influence on the local surface albedo and energy balance. Differential ablation between debris-covered and debris-free areas creates an unusual heterogeneous surface of topographically low, high-ablation, and topographically raised (‘pedestalled’), low-...

MacDonald, Grant J; Banwell, Alison F; Willis, Ian C; Mayer, David; Goodsell, Becky; MacAyeal, Douglas R

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Year Published: 2019

Persistence of intense, climate-driven runoff late in Mars history

Mars is dry today, but numerous precipitation-fed paleo-rivers are found across the planet’s surface. These rivers’ existence is a challenge to models of planetary climate evolution. We report results indicating that, for a given catchment area, rivers on Mars were wider than rivers on Earth today. We use the scale (width and wavelength) of Mars...

Kite, Edwin S.; Mayer, David; Wilson, Sharon A.; Davis, Joel M.; Lucas, Antoine S.; Stucky de Quay, Gaia

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Year Published: 2019

Better approaches to managing drought in the American Southwest

The second in a series of USGS Southwest Region (SWR) “Science Exchange” annual workshops, focused on USGS drought science. The participants considered how extreme drought conditions are evolving in much of the American southwest, with an emphasis on integrated drought science planning at the USGS bureau and program levels. The increased need for...

Lambert, Patrick; Titus, Timothy N.; Ostroff, Andrea

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Year Published: 2019

Dark halos produced by current impact cratering on Mars

Hundreds of new impact craters have been observed to form on Mars since spacecraft began imaging that planet. New impact craters produced visible ejecta deposits and many of them also have visible rays, similar to lunar and mercurian craters. However, some of the new martian impact craters have a circular feature of relatively...

Bart, Gwendolyn D.; Daubar, Ingrid J.; Ivanov, Boris A; Dundas, Colin M.; McEwen, Alfred S.

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Year Published: 2019

Evidence for plunging river plume deposits in the Pahrump Hills member of the Murray formation, Gale crater, Mars

Recent robotic missions to Mars have offered new insights into the extent, diversity and habitability of the Martian sedimentary rock record. Since the Curiosity rover landed in Gale crater in August 2012, the Mars Science Laboratory Science Team has explored the origins and habitability of ancient fluvial, deltaic, lacustrine and...

Stack, Kathryn M.; Grotzinger, John P.; Lamb, Michael P.; Gupta, Sanjeev; Rubin, David M.; Kah, Linda C.; Edgar, Lauren A.; Fey, Deirdra M.; Hurowitz, Joel A.; McBride, Marie J.; Rivera-Hernández, Frances; Sumner, Dawn Y.; Van Beek, Jason K.; Williams, Rebecca M. E.; Yingst, R. Aileen

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Year Published: 2019

Planetary geologic mapping—Program status and future needs

The United States Geological Survey’s (USGS) Planetary Geologic Map Coordination Group (Flagstaff, Ariz.) surveyed planetary geoscience map makers and users to determine the importance, relevance, and usability of such products to their planetary science research and to current and future needs of the planetary science community. This survey was...

Skinner, James A.; Huff, Alexandra E.; Fortezzo, Corey M.; Gaither, Tenielle; Hare, Trent M.; Hunter, Marc A.; Buban, Holly
Skinner, J.A. Jr., Huff, A.E., Fortezzo, C.M., Gaither, T., Hare, T.M., Hunter, M.A., Buban, H., 2019, Planetary geologic mapping—program status and future needs: U.S. Geological Survey Open-File Report 2019–1012, 40 p., https://doi.org/10.3133/ofr20191012