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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…
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…
Life cycles of spots on Jupiter from Cassini images
Porco, Carolyn C.; Ingersoll, Andrew P.; Ewald, Shawn P. +3 more
Using the sequence of 70-day continuum-band (751 nm) images from the Cassini Imaging Science System (ISS), we record over 500 compact oval spots and study their relation to the large-scale motions. The ∼100 spots whose vorticity could be measured—the large spots in most cases—were all anticyclonic. We exclude cyclonic features (chaotic regions) be…
Cassini between Earth and asteroid belt: first in-situ charge measurements of interplanetary grains
Kempf, S.; Krüger, H.; Srama, R. +9 more
Dust particles in interplanetary space are expected to charge up to an electrostatic potential of about +5 V mostly by the solar UV (Horányi, 1996, Annu. Rev. Astrophys. 34, 383). Since the dynamics of charged grains may be quite different from neutral particles, the knowledge of the grain charge Qd is highly desirable. In the last two …
Cassini observations of Io's visible aurorae
Geissler, Paul; McEwen, Alfred; Porco, Carolyn +4 more
More than 500 images of Io in eclipse were acquired by the Cassini spacecraft in late 2000 and early 2001 as it passed through the jovian system en route to Saturn (Porco et al., 2003, Science 299, 1541-1547). Io's bright equatorial glows were detected in Cassini's near-ultraviolet filters, supporting the interpretation that the visible emissions …
Ion winds in Saturn's southern auroral/polar region
Stallard, Tom S.; Miller, Steve; Geballe, Thomas R. +2 more
We present profiles of the line-of-sight (l.o.s.) ionospheric wind velocities in the southern auroral/polar region of Saturn. Our velocities are derived from the measurement of Doppler shifting of the H 3+ν2Q(1,0 -) line at 3.953 microns. The data for this study were obtained using the facility high-reso…