Showing papers by "Kenneth P. Klaasen published in 1998"
TL;DR: High-resolution Galileo spacecraft images of Europa are presented, in which evidence for mobile ‘icebergs’ is found and the detailed morphology of the terrain strongly supports the presence of liquid water at shallow depths below the surface, either today or at some time in the past.
Abstract: Ground-based spectroscopy of Jupiter's moon Europa, combined with gravity data, suggests that the satellite has an icy crust roughly 150 km thick and a rocky interior In addition, images obtained by the Voyager spacecraft revealed that Europa's surface is crossed by numerous intersecting ridges and dark bands (called lineae) and is sparsely cratered, indicating that the terrain is probably significantly younger than that of Ganymede and Callisto It has been suggested that Europa's thin outer ice shell might be separated from the moon's silicate interior by a liquid water layer, delayed or prevented from freezing by tidal heating; in this model, the lineae could be explained by repetitive tidal deformation of the outer ice shell However, observational confirmation of a subsurface ocean was largely frustrated by the low resolution (>2 km per pixel) of the Voyager images Here we present high-resolution (54 m per pixel) Galileo spacecraft images of Europa, in which we find evidence for mobile 'icebergs' The detailed morphology of the terrain strongly supports the presence of liquid water at shallow depths below the surface, either today or at some time in the past Moreover, lower-resolution observations of much larger regions suggest that the phenomena reported here are widespread
521 citations
TL;DR: Io has been monitored during the nominal Galileo satellite tour from mid 1996 through late 1997 by the Solid State Imaging (SSI) experiment, which was able to observe many manifestations of active volcanism, including changes in the color and albedo of the surface, active airborne plumes, and glowing vents seen in eclipse as discussed by the authors.
197 citations
TL;DR: For example, images of Europa from the Galileo spacecraft show a surface with a complex history involving tectonic deformation, impact cratering, and possible emplacement of ice-rich materials and perhaps liquids on the surface as discussed by the authors.
153 citations
TL;DR: Banfieldet et al. as discussed by the authors measured a strong northeast flow approaching the hot spot, indicating either massive horizontal convergence or the presence of a large anticyclonic vortex southeast of the hot spots.
134 citations
TL;DR: In this article, a change in tectonic style with time is suggested in the Uruk Sulcus region, varying from horst and graben faulting for the oldest grooved terrain units to tilt block normal faulting in the latest units.
103 citations
TL;DR: In this paper, the authors measured the near-opposition spectrophotometric behavior of four primary europan terrain materials: IR-bright icy materials, IR-dark icy material, dark lineament material, and dark spot material.
79 citations
TL;DR: The images of the inner small jovian satellites obtained by the Galileo Solid State Imaging (SSI) experiment have much more detailed shape, color, and photometric information than were provided previously by Voyager images.
58 citations
TL;DR: The first images of the aurora were taken by the Galileo spacecraft's Solid State Imaging (SSI) camera on November 9, 1996 and again on April 2, 1997 as mentioned in this paper.
56 citations
TL;DR: In this article, the authors extracted spectra representing Europa's diverse geologic terrains and determined the number of color components necessary to explain Europa's dark material spectral behavior, and examined how europan dark materials may change in color with time.
34 citations