Skip to main content
U.S. flag

An official website of the United States government

Publications

Filter Total Items: 959

Titan's surface from the Cassini RADAR radiometry data during SAR mode Titan's surface from the Cassini RADAR radiometry data during SAR mode

We present initial results on the calibration and interpretation of the high-resolution radiometry data acquired during the Synthetic Aperture Radar (SAR) mode (SAR-radiometry) of the Cassini Radar Mapper during its first five flybys of Saturn's moon Titan. We construct maps of the brightness temperature at the 2-cm wavelength coincident with SAR swath imaging. A preliminary radiometry...
Authors
F. Paganelli, M.A. Janssen, R.M. Lopes, E. Stofan, S. D. Wall, R. D. Lorenz, J. I. Lunine, Randolph L. Kirk, L. Roth, C. Elachi

Seasonally active frost-dust avalanches on a north polar scarp of Mars captured by HiRISE Seasonally active frost-dust avalanches on a north polar scarp of Mars captured by HiRISE

North-polar temporal monitoring by the High Resolution Imaging Science Experiment (HiRISE) orbiting Mars has discovered new, dramatic examples that Mars1 CO2-dominated seasonal volatile cycle is not limited to quiet deposition and sublimation of frost. In early northern martian spring, 2008, HiRISE captured several cases of CO2 frost and dust cascading down a steep, polar scarp in...
Authors
Patrick S. Russell, Nicolas Thomas, Shane Byrne, Kenneth E. Herkenhoff, Kathryn E. Fishbaugh, Nathan Bridges, Chris Okubo, Moses P. Milazzo, Ingrid J. Daubar, Candice J. Hansen, Alfred S. McEwen

Composition and origin of the Dewar geochemical anomaly Composition and origin of the Dewar geochemical anomaly

Dewar crater is a 50-km diameter impact structure located in the highlands northwest of the South Pole–Aitken basin on the lunar farside. A low-albedo area with enhanced Th and Sm values is centered east-northeast of Dewar crater. This area also exhibits elevated FeO abundances (9.0–16.6 wt %) and TiO2 values (0.6–2 wt %). The range of FeO and TiO2 abundances determined for the darkest...
Authors
Samuel J. Lawrence, B. Ray Hawke, Jeffrey J. Gillis-Davis, G. Jeffrey Taylor, David J. Lawrence, Joshua T. Cahill, Justin Hagerty, Paul G. Lucey, Gregory A. Smith, Klaus Keil

North polar region of Mars: Advances in stratigraphy, structure, and erosional modification North polar region of Mars: Advances in stratigraphy, structure, and erosional modification

We have remapped the geology of the north polar plateau on Mars, Planum Boreum, and the surrounding plains of Vastitas Borealis using altimetry and image data along with thematic maps resulting from observations made by the Mars Global Surveyor, Mars Odyssey, Mars Express, and Mars Reconnaissance Orbiter spacecraft. New and revised geographic and geologic terminologies assist with...
Authors
Kenneth L. Tanaka, J. Alexis P. Rodriguez, James A. Skinner, Mary C. Bourke, Corey M. Fortezzo, Kenneth E. Herkenhoff, Eric J. Kolb, Chris Okubo

Mountains on Titan observed by Cassini Radar Mountains on Titan observed by Cassini Radar

The Cassini Titan Radar mapper has observed elevated blocks and ridge-forming block chains on Saturn's moon Titan demonstrating high topography we term “mountains.” Summit flanks measured from the T3 (February 2005) and T8 (October 2005) flybys have a mean maximum slope of 37° and total elevations up to 1930 m as derived from a shape-from-shading model corrected for the probable effects...
Authors
Jani Radebaugh, Ralph D. Lorenz, Randolph L. Kirk, Jonathan I. Lunine, Ellen R. Stofan, Rosaly Lopes, Stephen D. Wall

Abstracts of the Annual Meeting of Planetary Geologic Mappers, Tucson, AZ 2007 Abstracts of the Annual Meeting of Planetary Geologic Mappers, Tucson, AZ 2007

Introduction Report of the Annual Mappers Meeting Planetary Science Institute Tucson, Arizona June 28 and 29, 2007 Approximately 22 people attended this year's mappers meeting, and many more submitted abstracts and maps in absentia. The 2007 meeting was convened by Tracy Gregg, Les Bleamaster, Steve Saunders, and Ken Tanaka and was hosted by David Crown and Les Bleamaster of the...
Authors
Tracy Gregg, Kenneth L. Tanaka, R. Stephen Saunders

Ultrahigh resolution topographic mapping of Mars with HiRISE stereo images: Methods and first results Ultrahigh resolution topographic mapping of Mars with HiRISE stereo images: Methods and first results

The Mars Reconnaissance Orbiter (MRO) arrived at Mars on 10 March 2006 and began its primary science phase in November. The High Resolution Imaging Science Experiment (HiRISE) on MRO is the largest, most complex camera ever flown to another planet. Plans call for this scanner to image roughly 1% of Mars by area at a pixel scale of 0.3 m during the next Mars year. Among the thousands of...
Authors
Randolph L. Kirk, Elpitha Howington-Kraus, Mark R. Rosiek, Debbie Cook, Jeffery A. Anderson, Kris J. Becker, Brent A. Archinal, Laszlo P. Keszthelyi, R. King, Alfred S. McEwen

Cartography for lunar exploration: Current status and planned missions Cartography for lunar exploration: Current status and planned missions

The initial spacecraft exploration of the Moon in the 1960s–70s yielded extensive data, primarily in the form of film and television images, that were used to produce a large number of hardcopy maps by conventional techniques. A second era of exploration, beginning in the early 1990s, has produced digital data including global multispectral imagery and altimetry, from which a new...
Authors
Randolph L. Kirk, Brent A. Archinal, Lisa R. Gaddis, Mark R. Rosiek

Mars Global Digital Dune Database: MC2-MC29 Mars Global Digital Dune Database: MC2-MC29

Introduction The Mars Global Digital Dune Database presents data and describes the methodology used in creating the database. The database provides a comprehensive and quantitative view of the geographic distribution of moderate- to large-size dune fields from 65? N to 65? S latitude and encompasses ~ 550 dune fields. The database will be expanded to cover the entire planet in later...
Authors
Rosalyn K. Hayward, Kevin F. Mullins, L.K. Fenton, T.M. Hare, T.N. Titus, M.C. Bourke, Anthony Colaprete, P. R. Christensen

Report on the final completion of the Unified Lunar Control Network 2005 and Lunar Topographic Model Report on the final completion of the Unified Lunar Control Network 2005 and Lunar Topographic Model

In order to highlight this project to the extraterrestrial mapping community, we repeat here our earlier abstract [1], with a corrected Figure 2. A report describing the Unified Lunar Control Network 2005 and the files associated with that network is now available as an on-line USGS Open-File Report [2] at the location http://pubs.usgs.gov/of/2006/1367/. A “Readme” file describes the...
Authors
Brent A. Archinal, Mark R. Rosiek, Randolph L. Kirk, Trent M. Hare, Bonnie L. Redding

First stereoscopic radar images of Titan First stereoscopic radar images of Titan

Saturn's giant, cloud-covered satellite Titan, larger than the planet Mercury, is the last major piece of unexplored real estate in the Solar system. The NASA/ESA Cassini spacecraft carries a variety of instruments that are being used to map the surface of Titan, including optical instruments that provide a global synoptic view and spectroscopic information, and microwave imager (Cassini...
Authors
Randolph L. Kirk, Elpitha Howington-Kraus, K. L. Mitchell, S. Hensley, B.W. Stiles
Was this page helpful?