Search Publications
The CO Abundance on Neptune from HST Observations
Strobel, Darrell; Gautier, Daniel; Courtin, Régis
We have marginally detected two CO absorption bands in the UV reflection spectrum of Neptune measured by the HST Faint Object Spectrograph (FOS). They are the (1, 0) and (0, 0) Cameron bands at 1992 and 2063 Å. The interpretation of these features with a radiative transfer model-including Rayleigh, Raman, and particulate scattering processes-impli…
Dust Outflow Velocity of Comet Shoemaker-Levy 9
Hahn, Joseph M.; Rettig, Terrence W.; Sobczak, Gregory J.
Tidal dispersal of the dust comae of the ∼21 fragments of Comet Shoemaker-Levy 9 (S-L 9) became very pronounced in Hubble Space Telescope observations during the weeks prior to impact with Jupiter (T. W. Rettig, J. Hahn, S. C. Tegler, M. Mumma, and M. DiSanti 1994a,Periodic Comet Shoemaker-Levy 9(1993e), IAU Circular 6028; H. A. Weaver plus 20 oth…
HST Observation of Mg +in Outburst from Comet D/Shoemaker-Levy 9
Stern, S. A.; Feldman, P. D.; Weaver, H. A. +1 more
Ultraviolet spectra of fragment G1 of Comet D/Shoemaker-Levy 9 taken 4 days before impact (on 14 July 1994) by the Faint Object Spectrograph of the Hubble Space Telescope show a brief outburst of magnesium ions. The Mg+emission decays back to its quiescent (undetectable) level with a time constant of ∼1 min, consistent with the ions bei…
Compositional Mapping of Jupiter's Satellite Io Utilizing High Speed Multifilter Photometry during Mutual Satellite Occultations, 1990-1991
Lane, Arthur L.; Nelson, Robert M.; Hapke, Bruce W. +4 more
We observed selected mutual occultations of Jupiter's satellites in 1990-1991 at four wavelengths and we used the occultation profiles to constrain the areal distribution of selected spectrally active compounds on Io's surface. We performed high speed photometry of Io at four wavelengths while it was being occulted by another Galilean satellite. T…
Temperature inversion in the Io plasma torus.
Moncuquet, Michel; Meyer-Vernet, Nicole; Hoang, Sang
We present in situ measurements of electron parameters as a function of latitude in the Io plasma torus, deduced from an extended analysis of the radio and plasma wave data acquired on board Ulysses. We find that the density and temperature are anti-correlated and obey an approximate polytrope law Te ∝ √{1/ne}. We interpret t…
Clouds and circulation on Neptune: Implications of 1991 HST observations.
Limaye, Sanjay S.; Sromovsky, Lawrence A.; Fry, Patrick M.
Images of Neptune recorded by the Hubble Space Telescope (HST) Wide Fields/Planetary Camera in late 1991 provide a basis for the first significant comparison with the circulation results obtained from Voyager 2 observations 2 years earlier. The HST images using red (F675W) and methane band (F889N) filters contain isolated bright cloud features sui…
Imaging of Asteroid 4179 Toutatis with the Hubble Space Telescope
Weaver, H. A.; Noll, Keith S.; Storrs, A. D. +1 more
We obtained four images of the asteroid 4179 Toutatis during its close approach to the Earth on 10 December 1992 with the planetary camera of the Hubble Space Telescope. The distance between the Earth and Toutatis at the time of our observations was 0.0291 AU (4.35 × 10 6 km); a single planetary camera pixel width subtends a distance of…
Detection of the SO2 Atmosphere on Io with the Hubble Space Telescope
Feldman, P. D.; Moos, H. W.; Ballester, G. E. +3 more
Observations of the trailing hemisphere of Io made with the Faint Object Spectrograph of the Hubble Space Telescope in March 1992 have resulted in the first detection of atmospheric SO2 absorption bands in the ultraviolet. These observations represent only the third positive means of detection of what is widely believed to be Io's prima…
Solar Flux Variability and the Lifetimes of Cometary H 2O and OH
Feldman, P. D.; Festou, M. C.; Budzien, S. A.
The far and extreme ultraviolet (FUV/EUV) solar flux determines the photodestruction rates of H2O and OH in cometary comae and affects their spatial density distributions. Between the minimum and maximum of the solar activity cycle, the solar flux varies by as much as a factor of 2-3 at some FUV and EUV wavelengths. From recent cross se…
Monitoring Mars with the Hubble Space Telescope: 1990-1991 Observations
Clancy, R. Todd; James, Philip B.; Lee, Steven W. +5 more
Images of Mars obtained using the Planetary Camera on the Hubble Space Telescope during 1990 and 1991 are described and analyzed. Multispectral images of Mars record the martian season between Ls = 348° and 60° corresponding to late winter and spring in the northern hemisphere. The wavelengths of these observations varied between 230 nm…