Skip to main content
U.S. flag

An official website of the United States government

Publications

Filter Total Items: 922

Evidence for the interior evolution of Ceres from geologic analysis of fractures

Ceres is the largest asteroid belt object, and the Dawn spacecraft observed Ceres since 2015. Dawn observed two morphologically distinct linear features on Ceres's surface: secondary crater chains and pit chains. Pit chains provide unique insights into Ceres's interior evolution. We interpret pit chains called the Samhain Catenae as the surface expression of subsurface fractures. Using the pit cha
Authors
Jennifer E. C. Scully, Debra Buczkowski, Nico Schmedemann, Carol A. Raymond, Julie C. Castillo-Rogez, Scott King, Michael T. Bland, Anton Ermakov, D.P. O'Brien, S. Marchi, A. Longobardo, C.T. Russell, R.R. Fu, M. Neveu

Basalt–trachybasalt samples in Gale Crater, Mars

The ChemCam instrument on the Mars Science Laboratory (MSL) rover, Curiosity, observed numerous igneous float rocks and conglomerate clasts, reported previously. A new statistical analysis of single‐laser‐shot spectra of igneous targets observed by ChemCam shows a strong peak at ~55 wt% SiO2 and 6 wt% total alkalis, with a minor secondary maximum at 47–51 wt% SiO2 and lower alkali content. The cen
Authors
Peter H. Edwards, John C. Bridges, Roger C. Wiens, Ryan B. Anderson, M. Darby Dyar, Martin Fisk, Lucy Thompson, Patrick J. Gasda, Justin Filiberto, Susanne P. Schwenzer, Diana L. Blaney, Ian Hutchinson

Preface: The lunar reconnaissance orbiter

When the call for papers for a special issue of Icarus devoted to analysis of data from the Lunar Reconnaissance Orbiter mission was announced in March 2015 we envisioned a single issue with only a possibility of a second. We certainly were gratified by the response from within and outside the LRO instrument teams such that we were compelled to publish this the third and final volume. It is a test
Authors
John W Keller, Lisa R. Gaddis, Noah E. Petro, Oded Aharonson

Correcting spacecraft jitter in HiRISE images

Mechanical oscillations or vibrations on spacecraft, also called pointing jitter, cause geometric distortions and/or smear in high resolution digital images acquired from orbit. Geometric distortion is especially a problem with pushbroom type sensors, such as the High Resolution Imaging Science Experiment (HiRISE) instrument on board the Mars Reconnaissance Orbiter (MRO). Geometric distortions occ
Authors
S. S. Sutton, A.K. Boyd, Randolph L. Kirk, Debbie Cook, Jean Backer, A. Fennema, R. Heyd, A.S. McEwen, S.D. Mirchandani

Community tools for cartographic and photogrammetric processing of Mars Express HRSC images

The High Resolution Stereo Camera (HRSC) on the Mars Express orbiter (Neukum et al. 2004) is a multi-line pushbroom scanner that can obtain stereo and color coverage of targets in a single overpass, with pixel scales as small as 10 m at periapsis. Since commencing operations in 2004 it has imaged ~ 77 % of Mars at 20 m/pixel or better. The instrument team uses the Video Image Communication And Ret
Authors
Randolph L. Kirk, Elpitha Howington-Kraus, Kenneth L. Edmundson, Bonnie L. Redding, Donna M. Galuszka, Trent M. Hare, K. Gwinner

Spatial data analytics on heterogeneous multi- and many-core parallel architectures using python

Parallel vector spatial analysis concerns the application of parallel computational methods to facilitate vector-based spatial analysis. The history of parallel computation in spatial analysis is reviewed, and this work is placed into the broader context of high-performance computing (HPC) and parallelization research. The rise of cyber infrastructure and its manifestation in spatial analysis as C
Authors
Jason R. Laura, Sergio J. Rey

CO2 cycle

This chapter discusses the use of models, observations, and laboratory experiments to understand the cycling of CO2 between the atmosphere and seasonal Martian polar caps. This cycle is primarily controlled by the polar heat budget, and thus the emphasis here is on its components, including solar and infrared radiation, the effect of clouds (water- and CO2-ice), atmospheric transport, and subsurfa
Authors
Timothy N. Titus, Shane Byrne, Anthony Colaprete, Francois Forget, Timothy I. Michaels, Thomas H. Prettyman

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