Astrogeology Science Center

Publications

Filter Total Items: 889
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Year Published: 1996

The Topography of Asteroid Ida: A Comparison between Photogrammetric and Shape­Form-Shading Image Analysis

We derived high resolution Digital Terrain Models from stereo images of the asteroid Ida that were obtained by the Galileo spacecraft during the flyby in August 1993 and compared these results with terrain models derived from two-dimensional photoclinometry. The comparison shows that there are striking discrepancies between the results from the...

Giese, Bernd; Oberst, Juergen; Kirk, Randolph L.; Zeitler, W.

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Year Published: 1996

Modeling of fluidized ejecta emplacement over digital topography on Venus

The FLOW computer model of McEwen and Malin (1989) modified for application to the study of Venus fluidized ejecta blankets (FEBs) demonstrates that relatively low viscosities, yield strengths, and initial velocities are required to duplicate the observed flow paths of the outflow materials. The model calculates the velocities and simulated flow...

Johnson, Jeffrey R.; Gaddis, Lisa R.

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Year Published: 1996

Decomposition of AVIRIS spectra: Extraction of spectral reflectance, atmospheric, and instrumental components

Presents techniques that use only information contained within a raw, high-spectral-resolution, hyperspectral Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) scene to estimate and remove additive components (atmospheric scattering and instrument dark current). These techniques allow normalization of multiplicative components (instrument...

Gaddis, Lisa R.; Soderblom, Laurence A.; Kieffer, Hugh H.; Becker, Kris J.; Torson, James M.; Mullins, Kevin F.

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Year Published: 1996

A migratory mantle plume on Venus: Implications for Earth?

A spatially fixed or at least internally rigid hotspot reference frame has been assumed for determining relative plate motions on Earth. Recent 1:5,000,000 scale mapping of Venus, a planet without terrestrial-style plate tectonics and ocean cover, reveals a systematic age and dimensional progression of corona-like arachnoids occurring in an...

Chapman, Mary G.; Kirk, Randolph L.

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Year Published: 1996

Geology of 243 Ida

The surface of 243 Ida is dominated by the effects of impacts. No complex crater morphologies are observed. A complete range of crater degradation states is present, which also reveals optical maturation of the surface (darkening and reddening of materials with increasing exposure age). Regions of bright material associated with the freshest...

Sullivan, R.; Greeley, R.; Pappalardo, R.; Asphaug, E.; Moore, Johnnie N.; Morrison, D.; Belton, M.J.S.; Carr, M.; Chapman, C.R.; Geissler, Paul E.; Greenberg, R.; Granahan, J.; Head, J. W.; Kirk, Randolph L.; McEwen, A.; Lee, P.; Thomas, P.C.; Veverka, J.

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Year Published: 1996

City of Flagstaff Project: Ground Water Resource Evaluation, Remote Sensing Component

Many regions, cities, and towns in the Western United States need new or expanded water resources because of both population growth and increased development. Any tools or data that can help in the evaluation of an area's potential water resources must be considered for this increasingly critical need. Remotely sensed satellite images and...

Chavez, Pat S.; Velasco, Miguel G.; Bowell, Jo-Ann; Sides, Stuart C.; Gonzalez, Rosendo R.; Soltesz, Deborah L.
City of Flagstaff Project: Ground Water Resource Evaluation, Remote Sensing Component; 1996; OFR; 96-739; Chavez, Pat S., Jr.; Velasco, Miguel G.; Bowell, JoAnn; Sides, Stuart C.; Gonzalez, Rosendo R.; Soltesz, Deborah L.

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Year Published: 1995

Compositional variations on the Moon: Recalibration of Galileo solid‐state imaging data for the Orientale region and farside

Updated radiometric calibration and systematic processing procedures for Galileo solid‐state imaging (SSI) data from the first (1990) Earth‐Moon encounter are presented. These procedures were applied to a whole‐disk imaging sequence of the Moon centered near Mare Orientale, called Lunmap 14 (L14). Processing of L14 data included radiometric...

Gaddis, Lisa R.; McEwen, Alfred S.; Becker, Tammy L.

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Year Published: 1995

Data base of impact craters on Venus based on analysis of Magellan radar images and altimetry data

No abstract available.

Schaber, Gerald G.; Kirk, Randolph L.; Strom, Robert G.

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Year Published: 1995

Reply to comment on the global resurfacing of Venus

No abstract available.

Strom, R.G.; Schaber, G.G.; Dawson, D.D.; Kirk, Randolph L.

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Year Published: 1995

Velocities and mass balance of Pine Island Glacier, West Antarctica, derived from ERS-1 SAR images

Pine Island Glacier is one of the major ice streams draining West Antarctica. We calculated average velocities for both its grounded and floating parts by tracking crevasses and other patterns moving with the ice on two sequential images acquired in February and December 1992 by ERS-1 SAR (European Remote-Sensing Satellite, Synthetic Aperture...

Lucchitta, Baerbel K.; Rosanova, Christina E.; Mullins, K.F.

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Year Published: 1995

Geology of Triton

Triton, with a diameter of ≡2700 km, is Neptune's only planet-class satellite. The complexity of Triton's surface and the variety of surface features is unequaled among the satellites of the solar system. From a geologic viewpoint, some of Triton's features have apparently familiar morphologies and general interpretative agreement exists. However...

Cruikshank, Dale P.; Croft, S.K.; Kargel, J.S.; Kirk, Randolph L.; Moore, J.M.; Schenk, P.M.; Strom, R.G.

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Year Published: 1995

Triton's plumes: Discovery, characteristics, and models

This chapter presents (1) basic observations and characteristics of Triton's plumes (scale, geometry, optical properties, and temporal behavior); (2) the current best estimates of other parameters that can be derived directly or inferred from the observations (plume duration, wind velocities, particle properties, mass fluxes, energy requirements,...

Cruikshank, Dale P.; Kirk, Randolph L.; Soderblom, Laurence A.; Brown, R. H.; Kieffer, S.W.; Kargel, J.S.