Publications
Filter Total Items: 915
Slope activity in Gale crater, Mars
High-resolution repeat imaging of Aeolis Mons, the central mound in Gale crater, reveals active slope processes within tens of kilometers of the Curiosity rover. At one location near the base of northeastern Aeolis Mons, dozens of transient narrow lineae were observed, resembling features (Recurring Slope Lineae) that are potentially due to liquid water. However, the lineae faded and have not recu
Authors
Colin M. Dundas, Alfred S. McEwen
Temperature profile around a basaltic sill intruded into wet sediments
The transfer of heat into wet sediments from magmatic intrusions or lava flows is not well constrained from field data. Such field constraints on numerical models of heat transfer could significantly improve our understanding of water–lava interactions. We use experimentally calibrated pollen darkening to measure the temperature profile around a basaltic sill emplaced into wet lakebed sediments. I
Authors
Leslie Baker, Andrew Bernard, William C. Rember, Moses P. Milazzo, Colin M. Dundas, Oleg Abramov, Laszlo P. Kestay
Curiosity’s robotic arm-mounted Mars Hand Lens Imager (MAHLI): Characterization and calibration status
MAHLI (Mars Hand Lens Imager) is a 2-megapixel, Bayer pattern color CCD camera with a macro lens mounted on a rotatable turret at the end of the 2-meters-long robotic arm aboard the Mars Science Laboratory rover, Curiosity. The camera includes white and longwave ultraviolet LEDs to illuminate targets at night. Onboard data processing services include focus stack merging and data compression. Here
Authors
Kenneth S. Edgett, Michael A. Caplinger, Justin N. Maki, Michael A. Ravine, F. Tony Ghaemi, Sean McNair, Kenneth E. Herkenhoff, Brian M. Duston, Reg G. Wilson, R. Aileen Yingst, Megan R. Kennedy, Michelle E. Minitti, Aaron J. Sengstacken, Kimberley D. Supulver, Leslie J. Lipkaman, Gillian M. Krezoski, Marie J. McBride, Tessa L. Jones, Brian E. Nixon, Jason K. Van Beek, Daniel J. Krysak, Randolph L. Kirk
Evolution of Mars’ Northern Polar Seasonal CO2 deposits: variations in surface brightness and bulk density
Small scale variations of seasonal ice are explored at different geomorphic units on the Northern Polar Seasonal Cap (NPSC). We use seasonal rock shadow measurements, combined with visible and thermal observations, to calculate density over time. The coupling of volume density and albedo allows us to determine the microphysical state of the seasonal CO2 ice. We find two distinct endmembers across
Authors
Christopher P. Mount, Timothy N. Titus
The U.S. Geological Survey Geologic Collections Management System (GCMS)—A master catalog and collections management plan for U.S. Geological Survey geologic samples and sample collections
**Updated guidance is available in USGS Instructional Memorandum CSS 2019-01.**AbstractThe U.S. Geological Survey (USGS) is widely recognized in the earth science community as possessing extensive collections of earth materials collected by research personnel over the course of its history. In 2006, a Geologic Collections Inventory was conducted within the USGS Geology Discipline to determine the
Authors
The central uplift of Ritchey crater, Mars
Ritchey crater is a ∼79 km diameter complex crater near the boundary between Hesperian ridged plains and Noachian highland terrain on Mars (28.8°S, 309.0°E) that formed after the Noachian. High Resolution Imaging Science Experiment (HiRISE) images of the central peak reveal fractured massive bedrock and megabreccia with large clasts. Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) spe
Authors
Ning Ding, Veronica J. Bray, Alfred S. McEwen, Sarah S. Mattson, Chris H. Okubo, Matthew Chojnacki, Livio L. Tornabene
A field investigation of the basaltic ring structures of the Channeled Scabland and the relevance to Mars
The basaltic ring structure (BRS) is a class of peculiar features only reported in the Channeled Scabland of eastern Washington State. They have been suggested to be good analogs, however, for some circular features on Mars. BRSs are found where Pleistocene floods scoured the Columbia River Basin, stripping off the uppermost part of the Miocene Columbia River Basalt Group and exposing structures t
Authors
Laszlo P. Kestay, Windy L. Jaeger
Atypical pit craters on Mars: new insights from THEMIS, CTX and HiRISE observations
More than 100 pit craters in the Tharsis region of Mars exhibit morphologies, diameters and thermal behaviors that diverge from the much larger bowl-shaped pit craters that occur in most regions across Mars. These Atypical Pit Craters (APCs) generally have sharp and distinct rims, vertical or overhanging walls that extend down to their floors, surface diameters of ~50-350 m, and high depth-to-diam
Authors
Glen Cushing, Chris H. Okubo, Timothy N. Titus
Physical abrasion of mafic minerals and basalt grains: application to Martian aeolian deposits
Sediment maturity, or the mineralogical and physical characterization of sediment deposits, has been used to locate sediment source, transport medium and distance, weathering processes, and paleoenvironments on Earth. Mature terrestrial sands are dominated by quartz, which is abundant in source lithologies on Earth and is physically and chemically stable under a wide range of conditions. Immature
Authors
Carin Cornwall, Joshua L. Bandfield, Timothy N. Titus, B. C. Schreiber, D. R. Montgomery
ChemCam results from the Shaler outcrop in Gale crater, Mars
The ChemCam campaign at the fluvial sedimentary outcrop “Shaler” resulted in observations of 28 non-soil targets, 26 of which included active laser induced breakdown spectroscopy (LIBS), and all of which included Remote Micro-Imager (RMI) images. The Shaler outcrop can be divided into seven facies based on grain size, texture, color, resistance to erosion, and sedimentary structures. The ChemCam o
Authors
Ryan B. Anderson, J.C. Bridges, A. Williams, L. Edgar, A. Ollila, J. Williams, Marion Nachon, N. Mangold, M. Fisk, J. Schieber, S. Gupta, G. Dromart, R. Wiens, Stéphane Le Mouélic, O. Forni, N. Lanza, Alissa Mezzacappa, V. Sautter, D. Blaney, B. Clark, S. Clegg, O. Gasnault, J. Lasue, Richard Léveillé, E. Lewin, K.W. Lewis, S. Maurice, H. Newsom, S.P. Schwenzer, D. Vaniman
Cryovolcanism in the outer solar system
Cryovolcanism is defined as the extrusion of liquids and vapors of materials that would be frozen solid at the planetary surface temperatures of the icy bodies of the outer solar system. Active cryovolcanism is now known to occur on Saturn's moon Enceladus and on Neptune's moon Triton and is suspected on Jupiter's moon Europa, while evidence for past cryovolcanic activity is widespread throughout
Authors
Paul E. Geissler
Chemical variations in Yellowknife Bay formation sedimentary rocks analyzed by ChemCam on board the Curiosity rover on Mars
The Yellowknife Bay formation represents a ~5 m thick stratigraphic section of lithified fluvial and lacustrine sediments analyzed by the Curiosity rover in Gale crater, Mars. Previous works have mainly focused on the mudstones that were drilled by the rover at two locations. The present study focuses on the sedimentary rocks stratigraphically above the mudstones by studying their chemical variati
Authors
Nicolas Mangold, Olivier Forni, G. Dromart, K.M. Stack, Roger C. Wiens, Olivier Gasnault, Dawn Y. Sumner, Marion Nachon, Pierre-Yves Meslin, Ryan B. Anderson, Bruce Barraclough, J.F. Bell, G. Berger, D.L. Blaney, J.C. Bridges, F. Calef, Brian R. Clark, Samuel M. Clegg, Agnès Cousin, L. Edgar, Kenneth S. Edgett, B.L. Ehlmann, Cecile Fabre, M. Fisk, John P. Grotzinger, S.C. Gupta, Kenneth E. Herkenhoff, J.A. Hurowitz, J. R. Johnson, Linda C. Kah, Nina L. Lanza, Jeremie Lasue, S. Le Mouélic, Eric Lewin, Michael Malin, Scott M. McLennan, S. Maurice, Noureddine Melikechi, Alissa Mezzacappa, Ralph E. Milliken, H.L. Newsome, A. Ollila, Scott K. Rowland, Violaine Sautter, M.E. Schmidt, S. Schroder, C. D'Uston, Dave Vaniman, R. A. Williams