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Active Volcanism on Io as Seen by Galileo SSI
Geissler, Paul; Belton, Michael J. S.; Carr, Michael H. +11 more
Active volcanism on Io has been monitored during the nominal Galileo satellite tour from mid 1996 through late 1997. The Solid State Imaging (SSI) experiment was able to observe many manifestations of this active volcanism, including (1) changes in the color and albedo of the surface, (2) active airborne plumes, and (3) glowing vents seen in eclip…
Full Adaptive Optics Images of Asteroids Ceres and Vesta; Rotational Poles and Triaxial Ellipsoid Dimensions
Drummond, Jack D.; Fugate, Robert Q.; Christou, Julian C. +1 more
Adaptive optics (AO) images of asteroids Ceres and Vesta were obtained on September 18-20, 1993, with the 1.5-m telescope at the Starfire Optical Range of the USAF Phillips Laboratory located near Albuquerque, NM. The light source for higher-order wavefront correction was a Rayleigh laser beacon focused at a range of 10.5 km generated by a copper …
Models of the ISO 3-µm Reflection Spectrum of Jupiter
Feuchtgruber, H.; Drossart, P.; Knacke, R. F. +3 more
A spectrum of Jupiter in the 3-µm region obtained with the Infrared Space Observatory (ISO) shows evidence for the long-sought spectral signature of NH3ice particles in the jovian atmosphere. We calculated Jupiter 3-µm reflection spectrum, including multiple scattering by spherical cloud particles. Models containing reflecti…
On the Latitude Variation of Ammonia, Acetylene, and Phosphine Altitude Profiles on Jupiter from HST Faint Object Spectrograph Observations
Simon, A. A.; Edgington, S. G.; Atreya, S. K. +5 more
Ultraviolet spectra in the spectral region from 160 to 230 nm were taken with the Hubble Space Telescope Faint Object Spectrograph in May 1992. We analyze these data to obtain the altitude distribution of ammonia and its variation with latitude from 6°N to 25°N. Ammonia condenses below the 150-mbar level, above which it departs from saturation due…
Regression of Martian North Polar Cap: 1990-1997 Hubble Space Telescope Observations
Wolff, Michael J.; Cantor, Bruce A.; James, Philip B. +1 more
Hubble Space Telescope imaging of Mars from December 13, 1990, through April 17, 1997, has resulted in the synoptic monitoring of parts of four consecutive martian north polar cap regressional cycles spanningLs= 335.65° toLs= 144.56°. The 1990-1993 observations were obtained with the Wide Field Planetary Camera 1 (WFPC1) inst…
G Ring Particle Sizes Derived from Ring Plane Crossing Observations
Throop, Henry B.; Esposito, Larry W.
The Saturn ring plane crossings in 1995-1996 allowed observers using the Hubble Space Telescope and the W. M. Keck telescope to image the planet's diffuse rings from 0.3 to 2.2 µm at a scattering angle θ ∼ 175°. We calculate the G ring reflectance for size distributions of dust to kilometer-sized bodies derived from a physical, evolutionary …
Global Context of the Galileo-E6 Observations of Jupiter's White Ovals
Simon, Amy A.; Belton, Michael J. S.; Gierasch, Peter J. +3 more
Galileo Solid State Imaging (SSI) data taken during the E6 orbit on February 19, 1997 offer a brief, high-resolution glimpse of Jupiter's White Ovals. These data can be used to infer relative cloud heights and systematic rotations over a small area of latitude and longitude (approximately 20° by 30°) around the White Ovals. To fully understand the…
ISOCAM Imaging of Comets 65P/Gunn and 46P/Wirtanen
Fulle, M.; Mennella, V.; Colangeli, L. +4 more
In this paper we present images of Comets 65P/Gunn and 46P/Wirtanen obtained by means of ISOCAM in the broadband filters at 9.62 (LW7) and 15.00 µm (LW3). The observations were performed on 23 March 1996 and on 9 November 1996, respectively. The aim of this work is to analyze the coma and tail dust environment of the targets. The application…
The Ultraviolet Albedo of Titan
Smith, T. Ed; Feldman, Paul D.; Strobel, Darrell F. +2 more
Ultraviolet spectra of Titan obtained with the Faint Object Spectrograph of the Hubble Space Telescope in October 1991 and August 1992 have yielded a disk-average geometric albedo of 0.02-0.044 from 1800-3300 Å. These results are in excellent agreement with previous UV measurements from 2200-3300 Å spanning two decades, but have a significantly hi…
Dynamics and Interaction between a Large-Scale Vortex and the Great Red SPOT in Jupiter
Hueso, R.; Rojas, J. F.; Colas, F. +5 more
A unique large-scale vortex, the White Tropical Oval (WTrO), was first observed in the South Tropical Zone of Jupiter, at the latitude of the Great Red Spot (GRS) in 1983. Its origin is probably related to a period of intense formation of eddies in the Southern edge of the South Equatorial Belt at latitude -20°. The WTrO survived many changes in t…