Publications
Filter Total Items: 915
Viscous relaxation as a prerequisite for tectonic resurfacing on Ganymede: Insights from numerical models of lithospheric extension
Ganymede’s bright terrain formed during a near-global resurfacing event (or events) that produced both heavily tectonized and relatively smooth terrains. The mechanism(s) by which resurfacing occurred on Ganymede (e.g., cryovolcanic or tectonic), and the relationship between the older, dark and the younger, bright terrain are fundamental to understanding the geological evolution of the satellite.
Authors
Michael T. Bland, William B. McKinnon
6th international conference on Mars polar science and exploration: Conference summary and five top questions
We provide a historical context of the International Conference on Mars Polar Science and Exploration and summarize the proceedings from the 6th iteration of this meeting. In particular, we identify five key Mars polar science questions based primarily on presentations and discussions at the conference and discuss the overlap between some of those questions. We briefly describe the seven scientifi
Authors
Isaac B. Smith, Serina Diniega, David W. Beaty, Thorsteinn Thorsteinsson, Patricio Becerra, Ali Bramson, Stephen M. Clifford, Christine S. Hvidberg, Ganna Portyankina, Sylvain Piqueux, Aymeric Spiga, Timothy N. Titus
The Colour and Stereo Surface Imaging System (CaSSIS) for the ExoMars Trace Gas Orbiter
The Colour and Stereo Surface Imaging System (CaSSIS) is the main imaging system onboard the European Space Agency’s ExoMars Trace Gas Orbiter (TGO) which was launched on 14 March 2016. CaSSIS is intended to acquire moderately high resolution (4.6 m/pixel) targeted images of Mars at a rate of 10–20 images per day from a roughly circular orbit 400 km above the surface. Each image can be acquired in
Authors
N. Thomas, G. Cremonese, R. Ziethe, M. Gerber, M. Brändli, G. Bruno, M. Erismann, L. Gambicorti, T. Gerber, K. Ghose, M. Gruber, P. Gubler, H. Mischler, J. Jost, D. Piazza, A. Pommerol, M. Rieder, V. Roloff, A. Servonet, W. Trottmann, T. Uthaicharoenpong, C. Zimmermann, D. Vernani, M. Johnson, E. Pelò, T. Weigel, J. Viertl, N. De Roux, P. Lochmatter, G. Sutter, A. Casciello, T. Hausner, I. Ficai Veltroni, V. Da Deppo, P. Orleanski, W. Nowosielski, T. Zawistowski, S. Szalai, B. Sodor, S. Tulyakov, G. Troznai, M. Banaskiewicz, J.C. Bridges, S. Byrne, S. Debei, M. R. El-Maarry, E. Hauber, C.J. Hansen, A. Ivanov, L. Keszthelyil, Randolph L. Kirk, R. Kuzmin, N. Mangold, L. Marinangeli, W. J. Markiewicz, M. Massironi, A. S. McEwen, Chris H. Okubo, L.L. Tornabene, P. Wajer, J.J. Wray
Monitoring gas and heat emissions at Norris Geyser Basin, Yellowstone National Park, USA based on a combined eddy covariance and Multi-GAS approach
We quantified gas and heat emissions in an acid-sulfate, vapor-dominated area (0.04-km2) of Norris Geyser Basin, located just north of the 0.63 Ma Yellowstone Caldera and near an area of anomalous uplift. From 14 May to 3 October 2016, an eddy covariance system measured half-hourly CO2, H2O and sensible (H) and latent (LE) heat fluxes and a Multi-GAS instrument measured (1 Hz frequency) atmospheri
Authors
Jennifer L. Lewicki, Peter J. Kelly, Deborah Bergfeld, R. Greg Vaughan, Jacob B. Lowenstern
Origin of discrepancies between crater size-frequency distributions of coeval lunar geologic units via target property contrasts
Recent work on dating Copernican-aged craters, using Lunar Reconnaissance Orbiter (LRO) Camera data, re-encountered a curious discrepancy in crater size-frequency distribution (CSFD) measurements that was observed, but not understood, during the Apollo era. For example, at Tycho, Copernicus, and Aristarchus craters, CSFDs of impact melt deposits give significantly younger relative and absolute mod
Authors
Carolyn H. Van der Bogert, Harald Hiesinger, Colin M. Dundas, T. Kruger, Alfred S. McEwen, Michael Zanetti, Mark S. Robinson
The effects of snow and salt on ice table stability in University Valley, Antarctica
The Antarctic Dry Valleys represent a unique environment where it is possible to study dry permafrost overlaying an ice-rich permafrost. In this paper, two opposing mechanisms for ice table stability in University Valley are addressed: i) diffusive recharge via thin seasonal snow deposits and ii) desiccation via salt deposits in the upper soil column. A high-resolution time-marching soil and snow
Authors
Kaj E. Williams, Jennifer L. Heldmann, Christopher P. McKay, Michael T. Mellon
The interior structure of Ceres as revealed by surface topography
Ceres, the largest body in the asteroid belt (940 km diameter), provides a unique opportunity to study the interior structure of a volatile-rich dwarf planet. Variations in a planetary body's subsurface rheology and density affect the rate of topographic relaxation. Preferential attenuation of long wavelength topography (≥150 km) on Ceres suggests that the viscosity of its crust decreases with inc
Authors
Roger R. Fu, Anton Ermakov, Simone Marchi, Julie C. Castillo-Rogez, Carol A. Raymond, Bradford Hager, Maria Zuber, Scott D. King, Michael T. Bland, Maria Cristina De Sanctis, Frank Preusker, Ryan S. Park, Christopher T. Russell
Martian cave air-movement via Helmholtz resonance
Infrasonic resonance has previously been measured in terrestrial caves by other researchers, where Helmholtz resonance has been suggested as the plausible mechanism resulting in periodic wind reversals within cave entrances. We extend this reasoning to possible Martian caves, where we examine the characteristics of four atypical pit craters (APCs) on Tharsis, suggested as candidate cave entrance l
Authors
Kaj E. Williams, Timothy N. Titus, Chris Okubo, Glen E. Cushing
Pitted terrains on (1) Ceres and implications for shallow subsurface volatile distribution
Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to be ice-rich. Searches for morphological features related to ice have been ongoing during Dawn's mission at Ceres. Here we report the identification of pitted terrains associated with fresh Cerean impact craters. The Cerean pitted terrains exhibit strong morphological similarities to pitted materials previousl
Authors
H.G. Sizemore, Thomas Platz, Norbert Schorghofer, Thomas Prettyman, Maria Christina De Sanctis, David A. Crown, Nico Schmedemann, Andeas Nessemann, Thomas Kneissl, Simone Marchi, Paul M. Schenk, Michael T. Bland, B.E. Schmidt, Kynan H.G. Hughson, F. Tosi, F Zambon, S.C. Mest, R.A. Yingst, D.A. Williams, C.T. Russell, C.A. Raymond
Selection of the InSight landing site
The selection of the Discovery Program InSight landing site took over four years from initial identification of possible areas that met engineering constraints, to downselection via targeted data from orbiters (especially Mars Reconnaissance Orbiter (MRO) Context Camera (CTX) and High-Resolution Imaging Science Experiment (HiRISE) images), to selection and certification via sophisticated entry, de
Authors
M. Golombek, D. Kipp, N. Warner, Ingrid J. Daubar, Robin L. Fergason, Randolph L. Kirk, R. Beyer, A. Huertas, Sylvain Piqueux, N.E. Putzig, B.A. Campbell, G. A. Morgan, C. Charalambous, W. T. Pike, K. Gwinner, F. Calef, D. Kass, M. A. Mischna, J. Ashley, C. Bloom, N. Wigton, T. Hare, C. Schwartz, H. Gengl, L. Redmond, M. Trautman, J. Sweeney, C. Grima, I. B. Smith, E. Sklyanskiy, M. Lisano, J. Benardini, S.E. Smrekar, P. Lognonne, W. B. Banerdt
The Mars Science Laboratory Curiosity rover Mastcam instruments: Preflight and in-flight calibration, validation, and data archiving
The NASA Curiosity rover Mast Camera (Mastcam) system is a pair of fixed-focal length, multispectral, color CCD imagers mounted ~2 m above the surface on the rover's remote sensing mast, along with associated electronics and an onboard calibration target. The left Mastcam (M-34) has a 34 mm focal length, an instantaneous field of view (IFOV) of 0.22 mrad, and a FOV of 20° × 15° over the full 1648
Authors
James F. Bell, A. Godber, S. McNair, M.A. Caplinger, J.N. Maki, M. T. Lemmon, J. Van Beek, M.C. Malin, D. Wellington, K.M. Kinch, M.B. Madsen, C. Hardgrove, M.A. Ravine, E. Jensen, D. Harker, Ryan Anderson, Kenneth E. Herkenhoff, R.V. Morris, E. Cisneros, R. G. Deen
Viscous relaxation of Ganymede's impact craters: Constraints on heat flux
Measurement of crater depths in Ganymede’s dark terrain have revealed substantial numbers of unusually shallow craters indicative of viscous relaxation [see companion paper: Singer, K.N., Schenk, P. M., Bland, M.T., McKinnon, W.B., (2017). Relaxed impact craters on Ganymede: Regional variations and high heat flow. Icarus, submitted]. These viscously relaxed craters provide insight into the thermal
Authors
Michael T. Bland, Kelsi N. Singer, William B. McKinnon, Paul M. Schenk