Search Publications
Iapetus' near surface thermal emission modeled and constrained using Cassini RADAR Radiometer microwave observations
Lorenz, R. D.; Wye, L. C.; Janssen, M. A. +5 more
Since its arrival at Saturn, the Cassini spacecraft has had only a few opportunities to observe Iapetus, Saturn's most distant regular satellite. These observations were all made from long ranges (>100,000 km) except on September 10, 2007, during Cassini orbit 49, when the spacecraft encountered the two-toned moon during its closest flyby so fa…
From Voyager-IRIS to Cassini-CIRS: Interannual variability in Saturn’s stratosphere?
Fletcher, L. N.; Irwin, P. G. J.; Sinclair, J. A. +4 more
We present an intercomparison of Saturn’s stratosphere between Voyager 1-IRIS observations in 1980 and Cassini-CIRS observations in 2009 and 2010. Over a saturnian year (∼29.5 years) has now passed since the Voyager flybys of Saturn in 1980/1981. Cassini observations in 2009/2010 capture Saturn in the same season as Voyager observations (just afte…
Catastrophic ice lake collapse in Aram Chaos, Mars
Kleinhans, Maarten G.; Zegers, Tanja E.; Oosthoek, Jelmer H. P. +1 more
Hesperian chaotic terrains have been recognized as the source of outflow channels formed by catastrophic outflows. Four main scenarios have been proposed for the formation of chaotic terrains that involve different amounts of water and single or multiple outflow events. Here, we test these scenarios with morphological and structural analyses of im…
A comprehensive NMR structural study of Titan aerosol analogs: Implications for Titan's atmospheric chemistry
Smith, Mark A.; He, Chao
Titan has a thick atmosphere composed primarily of nitrogen and methane. Complex organic chemistry induced by solar ultraviolet radiation and energetic particles, takes place in Titan's upper atmosphere, producing an optically thick reddish brown carbon based haze encircling this moon. The chemistry in Titan's atmosphere and its resulting chemical…
Time variations of O2(a1Δ) nightglow spots on the Venus nightside and dynamics of the upper mesosphere
Drossart, Pierre; Piccioni, Giuseppe; Gérard, Jean-Claude +1 more
The dynamical regime of the Venus upper atmosphere is mainly decomposed into three regions. The first one, located below 65 km of altitude is governed by the retrograde superrotational zonal (RSZ) circulation. The second region above 130 km is dominated by the subsolar to antisolar (SS-AS) circulation. The dynamics of the transition region in betw…
Non-circular features in Saturn’s D ring: D68
Hedman, M. M.; Burns, J. A.; Showalter, M. R. +1 more
D68 is a narrow ringlet located only 67,627 km (1.12 planetary radii) from Saturn’s spin axis. Images of this ringlet obtained by the Cassini spacecraft reveal that this ringlet exhibits persistent longitudinal brightness variations and a substantial eccentricity (ae=25±1 km). By comparing observations made at different times, we confirm that the …
Seasonal and radial trends in Saturn’s thermal plasma between the main rings and Enceladus
Johnson, R. E.; Elrod, M. K.; Tseng, W. -L. +1 more
A goal of Cassini's extended mission is to examine the seasonal variations of Saturn's magnetosphere, moons, and rings. Recently we showed that the thermal plasma between the main rings and Enceladus exhibited a time dependence that we attributed to a seasonally variable source of oxygen from the main rings (Elrod, M.K., Tseng, W.-L., Wilson, R.J.…
Cassini ISS observation of Saturn’s String of Pearls
Dyudina, Ulyana A.; Ingersoll, Andrew P.; Ewald, Shawn P. +2 more
We present the dynamics of the String of Pearls (SoPs) feature observed by the Cassini spacecraft’s Imaging Science Subsystem (ISS) camera between 2007 and 2010. The SoPs was originally discovered in the 5 µm images captured by Cassini VIMS instrument, where it appeared as a chain of infrared-bright spots (Momary, T.W., et al. [2006]. The Zo…
The transit spectra of Earth and Jupiter
Aigrain, S.; Fletcher, L. N.; Lee, J. -M. +3 more
In recent years, an increasing number of observations have been made of the transits of 'Hot Jupiters', such as HD 189733b, about their parent stars from the visible through to mid-infrared wavelengths, which have been modelled to derive the likely atmospheric structure and composition of these planets. As measurement techniques improve, the measu…
The global vortex analysis of Jupiter and Saturn based on Cassini Imaging Science Subsystem
Li, Liming; Jiang, Xun; Trammell, Harold Justin +3 more
Presented in this manuscript are observations exploring vortices with diameters larger than 1000 km on Jupiter and Saturn. These images are taken from the Imaging Science Subsystem onboard the Cassini Spacecraft. The analyses of Saturn's vortices show that there are significantly more vortices in the Southern Hemisphere (SH) than in the Northern H…