Search Publications
Tidal dissipation within large icy satellites: Applications to Europa and Titan
Sotin, C.; Tobie, G.; Mocquet, A.
This paper describes a new approach based on variational principles to calculate the radial distribution of tidal energy dissipation in any satellite. The advantage of the model with respect to classical solutions, is that it relates in a straightforward way the radial distribution of the time-averaged dissipation rate to its sensitivity to the co…
A spectroscopic study of the surfaces of Saturn's large satellites: H 2O ice, tholins, and minor constituents
Emery, Joshua P.; Cruikshank, Dale P.; Owen, Tobias C. +7 more
We present spectra of Saturn's icy satellites Mimas, Enceladus, Tethys, Dione, Rhea, and Hyperion, 1.0-2.5 µm, with data extending to shorter (Mimas and Enceladus) and longer (Rhea and Dione) wavelengths for certain objects. The spectral resolution ( R=λ/Δλ) of the data shown here is in the range 800-1000, depending on the specific instrumen…
Cassini UVIS observations of Europa's oxygen atmosphere and torus
Hendrix, A. R.; Shemansky, Donald E.; Hansen, Candice J.
Observations of the Europa environment using the Cassini UltraViolet Imaging Spectrograph (UVIS) show the presence of an extended atomic oxygen atmosphere in addition to the bound molecular oxygen atmosphere first detected by Hubble Space Telescope in 1994 [D.T. Hall, D.F. Strobel, P.D. Feldman, M.A. McGrath, H.A. Weaver, 1995, Detection of an oxy…
Ejection of nitrogen from Titan's atmosphere by magnetospheric ions and pick-up ions
Luhmann, J. G.; Johnson, R. E.; Leblanc, F. +3 more
A 3-D Monte Carlo model is used to describe the ejection of N and N 2 from Titan due to the interaction of Saturn's magnetospheric N + ions and molecular pick-up ions with its N 2 atmosphere. Based on estimates of the ion flux into Titan's corona, atmospheric sputtering is an important source of both atomic and mol…
The cloud structure of the jovian atmosphere as seen by the Cassini/CIRS experiment
Flasar, F. Michael; Conrath, Barney J.; Gierasch, Peter J. +1 more
We analyze the thermal infrared spectra of Jupiter obtained by the Cassini-CIRS instrument during the 2000 flyby to infer temperature and cloud density in the jovian stratosphere and upper troposphere. We use an inversion technique to derive zonal mean vertical profiles of cloud absorption coefficient and optical thickness from a narrow spectral w…
Radar imaging of Saturn's rings
Nicholson, Philip D.; French, Richard G.; Campbell, Donald B. +4 more
We present delay-Doppler images of Saturn's rings based on radar observations made at Arecibo Observatory between 1999 and 2003, at a wavelength of 12.6 cm and at ring opening angles of 20.1°⩽|B|⩽26.7°. The average radar cross-section of the A ring is ∼77% relative to that of the B ring, while a stringent upper limit of 3% is placed on the cross-s…
Cassini UVIS observations of Jupiter's auroral variability
Dougherty, Michele K.; West, Robert A.; Gurnett, Donald A. +20 more
The Cassini spacecraft Ultraviolet Imaging Spectrograph (UVIS) obtained observations of Jupiter's auroral emissions in H 2 band systems and H Lyman- α from day 275 of 2000 (October 1), to day 81 of 2001 (March 22). Much of the globally integrated auroral variability measured with UVIS can be explained simply in terms of the rotation of …
Spectrophotometry of the small satellites of Saturn and their relationship to Iapetus, Phoebe, and Hyperion
Buratti, B. J.; Hicks, M. D.; Davies, A.
We have obtained broadband spectrophotometric observations of four of the recently discovered small satellites of Saturn (Gladman et al., 2001, Nature 412, 163-166). The new data enable an understanding of the provenance, composition, and interrelationships among these satellites and the other satellites of Saturn, particularly Iapetus, Phoebe, an…
HST observations of spokes in Saturn's B ring
French, Richard G.; Salo, Heikki J.; Dones, Luke +3 more
As part of a long-term study of Saturn's rings, we have used the Hubble Space Telescope's (HST) Wide Field and Planetary Camera (WFPC2) to obtain several hundred high resolution images from 1996 to 2004, spanning the full range of ring tilt and solar phase angles accessible from the Earth. Using these multiwavelength observations and HST archival …
Condensate clouds in Titan's north polar stratosphere
Samuelson, Robert E.; Mayo, Louis A.
Analysis of the 250-560 cm -1 spectral continuum of Titan's north polar hood just after spring equinox reveals, in addition to the ubiquitous aerosol, a tenuous but relatively uniform cloud of small particles permeating the lower stratosphere at altitudes between 58 and 90 km. Voyager 1 IRIS data suggest the particles are highly scatter…