Search Publications
An observed correlation between plume activity and tidal stresses on Enceladus
Sotin, C.; Brown, R. H.; Baines, K. H. +6 more
Saturn's moon Enceladus emits a plume of water vapour and micrometre-sized ice particles from a series of warm fissures located near its south pole. This geological activity could be powered or controlled by variations in the tidal stresses experienced by Enceladus as it moves around its slightly eccentric orbit. The specific mechanisms by which t…
Cryovolcanism on Titan: New results from Cassini RADAR and VIMS
Barnes, J. W.; Janssen, M. A.; Lunine, J. I. +13 more
The existence of cryovolcanic features on Titan has been the subject of some controversy. Here we use observations from the Cassini RADAR, including Synthetic Aperture Radar (SAR) imaging, radiometry, and topographic data as well as compositional data from the Visible and Infrared Mapping Spectrometer (VIMS) to reexamine several putative cryovolca…
Enceladus: An Active Ice World in the Saturn System
Nimmo, Francis; Spencer, John R.
Enceladus, one of the mid-sized icy moons of Saturn, has an importance to planetary science far greater than its modest 504-km diameter would suggest. Intensive exploration of Enceladus by the Cassini Saturn orbiter has revealed that it is the only known icy world in the solar system with ongoing deep-seated geological activity. Active tectonic fr…
Titan’s surface and atmosphere from Cassini/VIMS data with updated methane opacity
Le Mouélic, S.; Rodriguez, S.; Lellouch, E. +13 more
We present an analysis of Titan data acquired by the Cassini Visual and Infrared Mapping Spectrometer (VIMS), making use of recent improvements in methane spectroscopic parameters in the region 1.3-5.2 µm. We first analyzed VIMS spectra covering a 8 × 10-km2 area near the Huygens landing site in order to constrain the single scatt…
Large Abundances of Polycyclic Aromatic Hydrocarbons in Titan's Upper Atmosphere
López-Puertas, M.; D'Aversa, E.; García-Comas, M. +6 more
In this paper, we analyze the strong unidentified emission near 3.28 µm in Titan's upper daytime atmosphere recently discovered by Dinelli et al. We have studied it by using the NASA Ames PAH IR Spectroscopic Database. The polycyclic aromatic hydrocarbons (PAHs), after absorbing UV solar radiation, are able to emit strongly near 3.3 µm…
Kronoseismology: Using Density Waves in Saturn's C Ring to Probe the Planet's Interior
Nicholson, P. D.; Hedman, M. M.
Saturn's C ring contains multiple spiral patterns that appear to be density waves driven by periodic gravitational perturbations. In other parts of Saturn's rings, such waves are generated by Lindblad resonances with Saturn's various moons, but most of the wave-like C-ring features are not situated near any strong resonance with any known moon. Us…
Dynamics of Saturn’s great storm of 2010-2011 from Cassini ISS and RPWS
West, Robert A.; Porco, Carolyn C.; Dyudina, Ulyana A. +6 more
Saturn’s quasi-periodic planet-encircling storms are the largest convecting cumulus outbursts in the Solar System. The last eruption was in 1990 (Sánchez-Lavega, A. [1994]. Chaos 4, 341-353). A new eruption started in December 2010 and presented the first-ever opportunity to observe such episodic storms from a spacecraft in orbit around Saturn (Fi…
Magnetic signatures of Kelvin-Helmholtz vortices on Saturn's magnetopause: Global survey
Wilson, R. J.; Delamere, P. A.; Bagenal, F. +1 more
Saturn's rapid rotation combined with relatively weak magnetic fields in the outer magnetosphere and sheath lead to conditions that are favorable for the Kelvin-Helmholtz (KH) instability. A Kelvin-Helmholtz unstable magnetopause boundary has important consequences for Saturn's interaction with the solar wind due to mass, momentum, and energy tran…
Multispectral simultaneous diagnosis of Saturn's aurorae throughout a planetary rotation
Lamy, L.; Badman, S. V.; Brandt, P. C. +6 more
From 27 to 28 January 2009, the Cassini spacecraft remotely acquired combined observations of Saturn's southern aurorae at radio, ultraviolet, and infrared wavelengths, while monitoring ion injections in the middle magnetosphere from energetic neutral atoms. Simultaneous measurements included the sampling of a full planetary rotation, a relevant t…
The thermal structure of Titan’s upper atmosphere, I: Temperature profiles from Cassini INMS observations
Wahlund, J. -E.; Edberg, N. J. T.; Ågren, K. +3 more
We derive vertical temperature profiles from Ion Neutral Mass Spectrometer (INMS) N2 density measurements from 32 Cassini passes. We find that the average temperature of Titan’s thermosphere varies significantly from pass-to-pass between 112 and 175 K. The temperatures from individual temperature profiles also varies considerably, with …