Search Publications
Latitudinal variation of Saturn photochemistry deduced from spatially-resolved ultraviolet spectra
Fouchet, Thierry; Connerney, J. E. P.; Prangé, Renée +2 more
We obtained spatially-resolved ultraviolet spectra of Saturn in 1994 with the Faint Object Spectrometer and Goddard High Resolution Spectrograph of the Hubble Space Telescope. We observed four areas on the planet at 15° N, 33° S, 41° S, and 52° S, with a field-of-view of less than 2 × 2 arcsec 2, compared to the 16-arcsec planet diamete…
Discovery of a binary Centaur
Noll, Keith S.; Levison, Harold F.; Stephens, Denise C. +1 more
We have identified a binary companion to (42355) 2002 CR 46 in our ongoing deep survey using the Hubble Space Telescope's High Resolution Camera. It is the first companion to be found around an object in a non-resonant orbit that crosses the orbits of giant planets. Objects in orbits of this kind, the Centaurs, have experienced repeated…
Gravitational tidal waves in Titan's upper atmosphere
Strobel, Darrell F.
Tidal waves driven by Titan's orbital eccentricity through the time-dependent component of Saturn's gravitational potential attain nonlinear, saturation amplitudes ( |T|>10 K, |u|>20 ms, and |w|>5 cms) in the upper atmosphere (⩾500 km) due to the approximate exponential growth as the inverse square root of pressure. The gravitational tide…
Cassini ISS astrometric observations of the inner jovian satellites, Amalthea and Thebe
Porco, C. C.; Spitale, J. N.; Cooper, N. J. +1 more
We present a total of 289 new astrometric observations of the inner jovian satellites, Amalthea and Thebe, obtained using the Cassini ISS narrow angle camera. Observations were made using image sequences from 2000 December 11-12 (inbound) and 2001 January 15-16 (outbound), at phase angles of approximately 2° and 122°, respectively. Target distance…
The first detection of propane on Saturn
Bézard, Bruno; Moses, Julianne I.; Lacy, John H. +3 more
We report the first detection of propane, C 3H 8, in Saturn's stratosphere. Observations taken on September 8, 2002 UT at NASA's IRTF using TEXES, show multiple emission lines due to the 748 cm -1ν band of C 3H 8. Using a line-by-line radiative transfer code, we are able to fit the data by sca…
Interaction of moist convection with zonal jets on Jupiter and Saturn
Ingersoll, Andrew P.; Li, Liming; Huang, Xianglei
Observations suggest that moist convection plays an important role in the large-scale dynamics of Jupiter's and Saturn's atmospheres. Here we use a reduced-gravity quasigeostrophic model, with a parameterization of moist convection that is based on observations, to study the interaction between moist convection and zonal jets on Jupiter and Saturn…
Jupiter's White Oval turns red
Simon-Miller, Amy A.; Karkoschka, Erich; Chanover, Nancy J. +3 more
Jupiter's remaining White Oval changed color in late 2005 and became noticeably red in early 2006, as reported by amateur observers. We present wind and color analyses from high spatial resolution images taken with the Hubble Space Telescope Advanced Camera for Surveys in April 2006. These images suggest that the recent color change was tied to a …
A model of the ionosphere of Saturn's rings and its implications
Luhmann, J. G.; Tokar, R. L.; Johnson, R. E. +2 more
The detection of cold O2+ and O + ions in the vicinity of Saturn's rings during the Cassini Orbiter orbit insertion confirmed expectations that the rings would have a water product atmosphere and ionosphere. These observations prompted a new look at their origin and nature by Johnson et al. [Johnson, R.E., Luhmann, J.G., Tokar, R.L., Bo…
First ENA observations at Mars: Solar-wind ENAs on the nightside
Coates, A. J.; Kallio, E.; Fedorov, A. +44 more
We present measurements with an Energetic Neutral Atom (ENA) imager on board Mars Express when the spacecraft moves into Mars eclipse. Solar wind ions charge exchange with the extended Mars exosphere to produce ENAs that can spread into the eclipse of Mars due to the ions' thermal spread. Our measurements show a lingering signal from the Sun direc…
Energetic Neutral Atoms (ENA) at Mars: Properties of the hydrogen atoms produced upstream of the martian bow shock and implications for ENA sounding technique around non-magnetized planets
Coates, A. J.; Kallio, E.; Fedorov, A. +43 more
We have studied the interaction of fast solar wind hydrogen atoms with the martian atmosphere by a three-dimensional Monte Carlo simulation. These energetic neutral hydrogen atoms, H-ENAs, are formed upstream of the martian bow shock. Both H-ENAs scattered and non-scattered from the martian atmosphere/exosphere were studied. The colliding H-ENAs w…