Search Publications
New perspectives on Titan's upper atmosphere from a reanalysis of the Voyager 1 UVS solar occultations
Strobel, Darrell F.; Vervack, Ronald J.; Sandel, Bill R.
We have reanalyzed the Voyager 1 UVS solar occultations by Titan to expand upon previous analyses and to resolve inconsistencies that have been noted in the scientific literature. To do so, we have developed a detailed model of the UVS detector and improved both the data reduction methods and retrieval techniques. In comparison to the values previ…
Comet nucleus size distributions from HST and Keck telescopes
Marsden, B. G.; Meech, K. J.; Hainaut, O. R.
The Wide Field Camera (WFC) on the Hubble Space Telescope and the Low Resolution Imaging Spectrograph (LRIS) on the Keck II telescope have been used to image 21 distant dynamically new, long-period (LP) and short-period (SP) Jupiter-family (JF) comet nuclei (near aphelion), as part of a long-term program to search for physical differences between …
Cassini UVIS observations of the Io plasma torus. I. Initial results
Steffl, Andrew J.; Stewart, A. Ian F.; Bagenal, Fran
During the Cassini spacecraft's flyby of Jupiter (October, 2000-March, 2001), the Ultraviolet Imaging Spectrograph (UVIS) produced an extensive dataset consisting of 3349 spectrally dispersed images of the Io plasma torus. Here we present an example of the raw data and representative EUV spectra (561-1181 Å) of the torus, obtained on October 1, 20…
Cassini UVIS observations of the Io plasma torus. II. Radial variations
Steffl, Andrew J.; Stewart, A. Ian F.; Bagenal, Fran
On January 14, 2001, shortly after the Cassini spacecraft's closest approach to Jupiter, the Ultraviolet Imaging Spectrometer (UVIS) made a radial scan through the midnight sector of Io plasma torus. The Io torus has not been previously observed at this local time. The UVIS data consist of 2-D spectrally dispersed images of the Io plasma torus in …
Cassini VIMS observations of the Galilean satellites including the VIMS calibration procedure
Sotin, C.; Brown, R. H.; Baines, K. H. +22 more
The Visual and Infrared Mapping Spectrometer (VIMS) observed the Galilean satellites during the Cassini spacecraft's 2000/2001 flyby of Jupiter, providing compositional and thermal information about their surfaces. The Cassini spacecraft approached the jovian system no closer than about 126 Jupiter radii, about 9 million kilometers, at a phase ang…
Retrievals of jovian tropospheric phosphine from Cassini/CIRS
Irwin, P. G. J.; Calcutt, S. B.; Taylor, F. W. +4 more
On December 30th, 2000, the Cassini-Huygens spacecraft reached the perijove milestone on its continuing journey to the Saturnian System. During an extended six-month encounter, the Composite Infrared Spectrometer (CIRS) returned spectra of the jovian atmosphere, rings and satellites from 10-1400 cm -1 (1000-7 µm) at a programmable…
The atmospheric signature of Io's Prometheus plume and anti-jovian hemisphere: evidence for a sublimation atmosphere
Ballester, Gilda E.; Spencer, John R.; Howell, Robert R. +4 more
Using the Hubble Space Telescope's Space Telescope Imaging Spectrograph we have obtained for the first time spatially resolved 2000-3000 Å spectra of Io's Prometheus plume and adjoining regions on Io's anti-jovian hemisphere in the latitude range 60° N-60° S, using a 0.1″ slit centered on Prometheus and tilted roughly 45° to the spin axis. The SO …
Observations and temperatures of Io's Pele Patera from Cassini and Galileo spacecraft images
Turtle, Elizabeth P.; Radebaugh, Jani; McEwen, Alfred S. +4 more
Pele has been the most intense high-temperature hotspot on Io to be continuously active during the Galileo monitoring from 1996-2001. A suite of characteristics suggests that Pele is an active lava lake inside a volcanic depression. In 2000-2001, Pele was observed by two spacecraft, Cassini and Galileo. The Cassini observations revealed that Pele …
Search for spatial variation in the jovian 15N/ 14N ratio from Cassini/CIRS observations
Nixon, Conor A.; Irwin, Patrick G. J.; Fouchet, Thierry +4 more
We have used the spectra obtained by the Composite Infrared Spectrometer (CIRS) onboard the Cassini spacecraft to search for latitudinal variation in the 15N/ 14N ratio on Jupiter. We found no variations statistically significant given the observational and model uncertainties. The absence of latitudinal variations demonstrat…
Large impact features on middle-sized icy satellites
Schenk, Paul M.; McKinnon, William B.; Moore, Jeffrey M. +2 more
All of the large impact features of the middle-sized icy satellites of Saturn and Uranus that were clearly observed by the Voyager spacecraft are described. New image mosaics and stereo-and-photoclinometrically-derived digital elevation models are presented. Landforms related to large impact features, such as secondary craters and possible antipod…