Skip to main content
U.S. flag

An official website of the United States government

Publications

Filter Total Items: 959

Voyager 2 at Neptune: Imaging science results Voyager 2 at Neptune: Imaging science results

Voyager 2 images of Neptune reveal a windy planet characterized by bright clouds of methane ice suspended in an exceptionally clear atmosphere above a lower deck of hydrogen sulfide or ammonia ices. Neptune's atmosphere is dominated by a large anticyclonic storm system that has been named the Great Dark Spot (GDS). About the same size as Earth in extent, the GDS bears both many...
Authors
B.A. Smith, Laurence A. Soderblom, D. Banfield, C. Barnet, A.T. Basilevsky, R.F. Beebe, K. Bollinger, J. M. Boyce, A. Brahic, G.A. Briggs, R. H. Brown, C. Chyba, S.A. Collins, T. Colvin, A.F. Cook, D. Crisp, S.K. Croft, D. Cruikshank, J.N. Cuzzi, G. E. Danielson, M. E. Davies, E. DeJong, L. Dones, D. Godfrey, J. Goguen, I. Grenier, V. Haemmerle, H. Hammel, C.J. Hansen, C.P. Helfenstein, C. Howell, G.E. Hunt, A.P. Ingersoll, T. V. Johnson, J. Kargel, Randolph L. Kirk, D.I. Kuehn, S. Limaye, H. Masursky, A. McEwen, D. Morrison, T. Owen, W. Owen, J. B. Pollack, C.C. Porco, K. Rages, P. Rogers, D. Rudy, C. Sagan, J. Schwartz, E.M. Shoemaker, M. Showalter, B. Sicardy, D. Simonelli, J. Spencer, L.A. Sromovsky, C. Stoker, R.G. Strom, V.E. Suomi, S.P. Synott, R.J. Terrile, P. Thomas, W.R. Thompson, A. Verbiscer, J. Veverka

The case for planetary sample return missions The case for planetary sample return missions

The essential role of planetary sample studies in exploration of the solar system has been well established “Drake et al., 1987”. As part of the larger pursuit of comparative planetology, samples of other rocky planets (Mercury, Venus, Mars), planetary satellites, asteroids, and comets should reveal much about the materials and processes that formed Earth. In that context, Mars is an...
Authors
James L. Gooding, M. H. Carr, Christopher P McKay

Geologic analyses of Shuttle Imaging Radar (SIR-B) data of Kilauea Volcano, Hawaii Geologic analyses of Shuttle Imaging Radar (SIR-B) data of Kilauea Volcano, Hawaii

Analyses of imaging radar data of volcanic terranes on Earth and Venus have emphasized the need for a clearer understanding of how these data can be most effectively used to accomplish important volcanological goals, including the interpretation of eruptive styles and the characterization of the geologic history of volcanic centers. The second Shuttle Imaging Radar experiment (SIR-B)...
Authors
Lisa R. Gaddis, Peter J. Mouginis-Mark, Robert B. Singer, Verne Kaupp

The competition between thermal contraction and differentiation in the stress history of the Moon The competition between thermal contraction and differentiation in the stress history of the Moon

The scarcity of both extension and compression features on the Moon strongly constrains the history of the lunar radius—to variations of less than ±1 km over the past 3.8 Gyr. This limit has traditionally been interpreted as requiring a delicate balance between thermal contraction of the near‐surface and expansion of a substantial cold interior region. Recent theories of lunar origin (e...
Authors
Randolph L. Kirk, David J. Stevenson

Numerical analysis of Landsat Thematic Mapper images of Antarctica Numerical analysis of Landsat Thematic Mapper images of Antarctica

Landsat-5 Thematic Mapper (TM) data from Dronning [Queen] Maud Land, Antarctica, have been analysed to provide insights into physical properties of the ice sheet. Brightness (at-satellite) temperatures calculated from digital numbers of the thermal band (TM band 6), using state-of-the-art equations and constants (Markham and Barker 1986), are 8° to 20°C lower than temperatures measured...
Authors
Olav Orheim, Baerbel K. Lucchitta

The Martian surface The Martian surface

The past four years have been particularly fruitful for Martian research as the enormous volumes of data collected during the Viking mission became readily available to the general science community, and as reformatting of the remote sensing data into cartographic products made the data more useable. The 1:5,000,000‐scale map series is complete, and 1:2,000,000‐scale controlled mosaics...
Authors
M. H. Carr

I. Thermal evolution of Ganymede and implications for surface features. II. Magnetohydrodynamic constraints on deep zonal flow in the giant planets. III. A fast finite-element algorithm for two-dimensional photoclinometry I. Thermal evolution of Ganymede and implications for surface features. II. Magnetohydrodynamic constraints on deep zonal flow in the giant planets. III. A fast finite-element algorithm for two-dimensional photoclinometry

The work is divided into three independent papers: PAPER I: Thermal evolution models are presented for Ganymede, assuming a mostly differentiated initial state of a water ocean overlying a rock layer. The only heat sources are assumed to be primordial heat (provided by accretion) and the long-lived radiogenic heat sources in the rock component. As Ganymede cools, the ocean thins, and two...
Authors
Randolph L. Kirk

Snow and ice studies by thematic mapper and multispectral scanner Landsat images Snow and ice studies by thematic mapper and multispectral scanner Landsat images

Digitally enhanced Landsat Thematic Mapper (TM) images of Antarctica reveal snow and ice features to a detail never seen before in satellite images. The six TM reflective spectral bands have a nominal spatial resolution of 30 m, compared to 80 m for the Multispectral Scanner (MSS). TM bands 2–4 are similar to the MSS bands. TM infra-red bands 5 and 7 discriminate better between clouds...
Authors
Olav Orheim, Baerbel K. Lucchitta

Thermal evolution of a differentiated Ganymede and implications for surface features Thermal evolution of a differentiated Ganymede and implications for surface features

Thermal evolution models are presented for Ganymede, assuming a mostly differentiated initial state of a water ocean overlying a rock layer. The only heat sources are assumed to be primordial heat (provided by accretion) and the long-lived radiogenic heat sources in the rock component. As Ganymede cools, the ocean thins, and two ice layers develop, one above composed of ice I, and the...
Authors
Randolph L. Kirk, David J. Stevenson

Hydromagnetic constraints on deep zonal flows in the giant planets Hydromagnetic constraints on deep zonal flows in the giant planets

The observed zonal flows of the giant planets will, if they penetrate below the visible atmosphere, interact significantly with the planetary magnetic field outside the metallized core. The appropriate measure of this interaction is the Chandrasekhar number Q = H^2 /4πρνα^2 λ (H = radial component of the magnetic field, ν = eddy viscosity, λ = magnetic diffusivity, α^-1 = length scale on...
Authors
Randolph L. Kirk, David J. Stevenson

Valles Marineris, Mars: Wet debris flows and ground ice Valles Marineris, Mars: Wet debris flows and ground ice

Detailed study of the Valles Marineris equatorial troughs suggests that the landslides in that area contained water and probably were gigantic wet debris flows: one landslide complex generated a channel that has several bends and extends for 250 km. Further support for water or ice in debris masses includes rounded flow lobes and transport of some slide masses in the direction of the...
Authors
Baerbel K. Lucchitta
Was this page helpful?