Search Publications
Far-Ultraviolet Imaging of Jupiter's Aurora and the lo "Footprint"
Casertano, Stefano; Ballester, Gilda E.; Feldman, Paul D. +18 more
Far-ultraviolet images of Jupiter from the Hubble Space Telescope Wide Field Planetary Camera 2 reveal polar auroral emissions at 300 kilometer resolution and three times higher sensitivity than previously achieved. Persistent features include a main oval containing most of the emission and magnetically connected to the middle magnetosphere, diffu…
Detection of Ozone on Ganymede
Johnson, Robert E.; Weaver, Harold A.; Noll, Keith S. +2 more
An absorption band at 260 nanometers on the trailing hemisphere of Ganymede, identified as the Hartley band of ozone (O_3), was measured with the Hubble Space Telescope. The column abundance of ozone, 4.5 x 1016 per square centimeter, can be produced by ion impacts or by photochemical equilibrium with previously detected molecular oxyge…
Observations of Saturn's Ring-Plane Crossings in August and November 1995
Nicholson, Philip D.; French, Richard G.; Dones, Luke +7 more
Observations of Saturn's ring system with the Hubble Space Telescope during the 10 August 1995 Earth crossing and the 17 to 21 November 1995 solar crossing indicate that the F ring dominates their apparent edge-on thickness of 1.2 to 1.5 kilometers. The F ring is slightly inclined with respect to the A ring, which may explain the approximately 50-…
Solar Wind Magnetic Field Bending of Jovian Dust Trajectories
Forsyth, R.; Hamilton, D. P.; Phillips, J. L. +5 more
From September 1991 to October 1992, the cosmic dust detector on the Ulysses spacecraft recorded 11 short bursts, or streams, of dust. These dust grains emanated from the jovian system, and their trajectories were strongly affected by solar wind magnetic field forces. Analyses of the on-board measurements of these fields, and of stream approach di…
Time-Resolved Observations of Jupiter's Far-Ultraviolet Aurora
Casertano, Stefano; Ballester, Gilda E.; Krist, John E. +19 more
Simultaneous imaging and spectroscopic observations of Jupiter's far-ultraviolet aurora covering half a jovian rotation were made on 31 May 1994. The Hubble Space Telescope Wide Field Planetary Camera 2 images revealed dramatic and rapidly changing auroral features, including discrete longitudinal structures along the auroral ovals, with variable …
Observations of Saturn's Inner Satellites During the May 1995 Ring-Plane Crossing
Bosh, Amanda S.; Rivkin, Andrew S.
The 22 May 1995 Saturn ring-plane crossing was observed with the Hubble Space Telescope; the markedly reduced scattered light from the rings at this time allowed study of the small inner satellites of the Saturn system. Prometheus was further from its predicted location than expected based on uncertainties in the 1981 ephemerides propagated forwar…
Perspectives in Helioseismology
Scherrer, P. H.; Toomre, J.; Gough, D. O. +1 more
Helioseismology is probing the interior structure and dynamics of the sun with ever-increasing precision, providing a well-calibrated laboratory in which physical processes can be studied under conditions that are unattainable on Earth. Nearly 10 million resonant modes of oscillation are observable in the solar atmosphere, and their frequencies ne…
Fluorescent Hydroxyl Emissions from Saturn's Ring Atmosphere
Feldman, Paul D.; McGrath, Melissa A.; Holberg, J. B. +1 more
Just before Earth passed through Saturn's ring plane on 10 August 1995, the Hubble Space Telescope Faint Object Spectrograph detected ultraviolet fluorescent emissions from a tenuous atmosphere of OH molecules enveloping the rings. Brightnesses decrease with increasing distance above the rings, implying a scale height of about 0.45 Saturn radii (R…
Evidence for Supersonic Turbulence in the Upper Atmosphere of Jupiter
Clarke, John T.; Emerich, Claude; Ben Jaffel, Lotfi +4 more
Spectra of the hydrogen Lyman α (Ly-α) emission line profiles of the jovian dayglow, obtained by the Goddard High Resolution Spectrograph on the Hubble Space Telescope, appear complex and variable on time scales of a few minutes. Dramatic changes occur in the Ly-α bulge region at low latitudes, where the line profiles exhibit structures that corre…
Comparison of Galileo Probe and Earth-Based Translation Rates of Jupiter's Equatorial Clouds
Simon, Amy A.; Beebe, Reta F.; Huber, Lyle F.
The Doppler wind speeds derived from Galileo probe data are comparable with the maximum translation speeds observed in the equatorial zone by Voyager 1 and the Hubble Space Telescope. Slower published values of east-west winds are based on measurements of larger features and should be interpreted as translation rates of large weather systems inter…