Ultraviolet Imaging Spectroscopy Shows an Active Saturnian System

  title={Ultraviolet Imaging Spectroscopy Shows an Active Saturnian System},
  author={Larry W. Esposito and Joshua E. Colwell and Kristopher Larsen and William E. McClintock and A. Ian F. Stewart and Janet Tew Hallett and Donald E. Shemansky and Joseph M. Ajello and Candice J Hansen and Amanda R. Hendrix and Robert A. West and H. Uwe Keller and Axel Korth and Wayne R Pryor and Ralf Reulke and Yuk L. Yung},
  pages={1251 - 1255}
Neutral oxygen in the saturnian system shows variability, and the total number of oxygen atoms peaks at 4 × 1034. Saturn's aurora brightens in response to solar-wind forcing, and the auroral spectrum resembles Jupiter's. Phoebe's surface shows variable water-ice content, and the data indicate it originated in the outer solar system. Saturn's rings also show variable water abundance, with the purest ice in the outermost A ring. This radial variation is consistent with initially pure water ice… 
Enceladus' Varying Imprint on the Magnetosphere of Saturn
The bombardment of Saturn's moon Enceladus by >20–kiloelectron volt magnetospheric particles causes particle flux depletions in regions magnetically connected to its orbit, which provide key radial diffusion coefficients for energetic electrons and an independent measure of the inner magnetosphere's rotation velocity.
Enceladus' Water Vapor Plume
The Cassini spacecraft flew close to Saturn's small moon Enceladus three times in 2005 and observed stellar occultations on two flybys and confirmed the existence, composition, and regionally confined nature of a water vapor plume in the south polar region of Ence Gladus.
The Cassini UVIS Stellar Probe of the Titan Atmosphere
The Cassini Ultraviolet Imaging Spectrometer (UVIS) observed the extinction of photons from two stars by the atmosphere of Titan during the Titan flyby to determine the asymptotic kinetic temperature at the top of the atmosphere.
Composition, Structure, Dynamics, and Evolution of Saturn's Rings
Cassini observations confirm that Saturn’s rings are predominantly water ice. The particles in Saturn’s rings cover a range of sizes, from dust to small moons. Occultation results show the particles
Energetic ion acceleration in Saturn's magnetotail: Substorms at Saturn?
The Magnetospheric Imaging Instrument (MIMI) Ion and Neutral Camera (INCA) on the Cassini spacecraft has recorded abrupt increases in energetic neutral atom flux coming from the general direction of
Are plasma depletions in Saturn's ionosphere a signature of time‐dependent water input?
Recent radio occultation measurements by the Cassini spacecraft reveal the presence of numerous “ionospheric holes”, or plasma depletions, in Saturn's upper atmosphere that cannot be explained with
Identification of Saturn's magnetospheric regions and associated plasma processes: Synopsis of Cassini observations during orbit insertion
Saturn's magnetosphere is currently studied from the microphysical to the global scale by the Cassini‐Huygens mission. During the first half of 2004, in the approach phase, remote sensing
Origin of oxygen species in Titan's atmosphere
[1] The detection of O+ precipitating into Titan's atmosphere by the Cassini Plasma Spectrometer (CAPS) represents the discovery of a previously unknown source of oxygen in Titan's atmosphere. The
Enceladus: An Active Ice World in the Saturn System
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


Extreme Ultraviolet Observations from the Voyager 2 Encounter with Saturn
Combined analysis of helium (584 angstroms) airglow and the atmospheric occultations of the star δ Scorpii imply a vertical mixing parameter in Saturn's upper atmosphere of K (eddy diffusion
Composition and Dynamics of Plasma in Saturn's Magnetosphere
Over the A and B rings, an ionosphere in which O2+ and O+ are dominant is found, which suggests the possible existence of a layer of O2 gas similar to the atmospheres of Europa and Ganymede.
Detection of the hydroxyl radical in the Saturn magnetosphere
THE magnetosphere in the vicinity of the orbits of Saturn's icy satellites consists of a low-density plasma, in which the electrons are an order of magnitude cooler than the accompanying heavy ions1.
Voyager Photometry of Saturn's A Ring
Abstract Saturn's A Ring samples a wide range of dynamical environments, from the relatively unperturbed, optically thick inner region to the outer part of the ring, which contains numerous density
Compositional Evolution of Saturn's Rings Due to Meteoroid Bombardment
In this paper we address the question of compositional evolution in planetary ring systems subsequent to meteoroid bombardment. The huge surface area to mass ratio of planetary rings ensures that
Saturn's polar ionospheric flows and their relation to the main auroral oval
Abstract. We consider the flows and currents in Saturn's polar ionosphere which are implied by a three-component picture of large-scale magnetospheric flow driven both by planetary rotation and the
Control of Jupiter's radio emission and aurorae by the solar wind
The results show that both of these emissions are triggered by interplanetary shocks propagating outward from the Sun, which produces strong electric fields and therefore electron acceleration along the auroral field lines similar to the processes that occur during geomagnetic storms at the Earth.
Saturn's E Ring and Production of the Neutral Torus
Recent Hubble Space Telescope (HST) observations of the densities of neutralOH molecules that coexist with and are precursors of the plasma ions have constrained models for the plasma sources. An