@article{BurattiThomasRoussosetal.2019, author = {Buratti, Bonnie J. and Thomas, P. C. and Roussos, E. and Howett, Carly and Seiss, Martin and Hendrix, A. R. and Helfenstein, Paul and Brown, R. H. and Clark, R. N. and Denk, Tilmann and Filacchione, Gianrico and Hoffmann, Holger and Jones, Geraint H. and Khawaja, N. and Kollmann, Peter and Krupp, Norbert and Lunine, Jonathan and Momary, T. W. and Paranicas, Christopher and Postberg, Frank and Sachse, Manuel and Spahn, Frank and Spencer, John and Srama, Ralf and Albin, T. and Baines, K. H. and Ciarniello, Mauro and Economou, Thanasis and Hsu, Hsiang-Wen and Kempf, Sascha and Krimigis, Stamatios M. and Mitchell, Donald and Moragas-Klostermeyer, Georg and Nicholson, Philip D. and Porco, C. C. and Rosenberg, Heike and Simolka, Jonas and Soderblom, Laurence A.}, title = {Close Cassini flybys of Saturn's ring moons Pan, Daphnis, Atlas, Pandora, and Epimetheus}, series = {Science}, volume = {364}, journal = {Science}, number = {6445}, publisher = {American Assoc. for the Advancement of Science}, address = {Washington}, issn = {0036-8075}, doi = {10.1126/science.aat2349}, pages = {1053}, year = {2019}, abstract = {Saturn's main ring system is associated with a set of small moons that either are embedded within it or interact with the rings to alter their shape and composition. Five close flybys of the moons Pan, Daphnis, Atlas, Pandora, and Epimetheus were performed between December 2016 and April 2017 during the ring-grazing orbits of the Cassini mission. Data on the moons' morphology, structure, particle environment, and composition were returned, along with images in the ultraviolet and thermal infrared. We find that the optical properties of the moons' surfaces are determined by two competing processes: contamination by a red material formed in Saturn's main ring system and accretion of bright icy particles or water vapor from volcanic plumes originating on the moon Enceladus.}, language = {en} } @article{LiuSachseSpahnetal.2016, author = {Liu, Xiaodong and Sachse, Manuel and Spahn, Frank and Schmidt, Jurgen}, title = {Dynamics and distribution of Jovian dust ejected from the Galilean satellites}, series = {Journal of geophysical research, Planets}, volume = {121}, journal = {Journal of geophysical research, Planets}, publisher = {American Geophysical Union}, address = {Washington}, issn = {2169-9097}, doi = {10.1002/2016JE004999}, pages = {1141 -- 1173}, year = {2016}, abstract = {In this paper, the dynamical analysis of the Jovian dust originating from the four Galilean moons is presented. High-accuracy orbital integrations of dust particles are used to determine their dynamical evolution. A variety of forces are taken into account, including the Lorentz force, solar radiation pressure, Poynting-Robertson drag, solar gravity, the satellites' gravity, plasma drag, and gravitational effects due to nonsphericity of Jupiter. More than 20,000 dust particles from each source moon in the size range from 0.05 \&\#956;m to 1 cm are simulated over 8000 (Earth) years until each dust grain hits a sink (moons, Jupiter, or escape from the system). Configurations of dust number density in the Jovicentric equatorial inertial frame are calculated and shown. In a Jovicentric frame rotating with the Sun the dust distributions are found to be asymmetric. For certain small particle sizes, the dust population is displaced towards the Sun, while for certain larger sizes, the dust population is displaced away from the Sun. The average lifetime as a function of particle size for ejecta from each source moon is derived, and two sharp jumps in the average lifetime are analyzed. Transport of dust between the Galilean moons and to Jupiter is investigated. Most of the orbits for dust particles from Galilean moons are prograde, while, surprisingly, a small fraction of orbits are found to become retrograde mainly due to solar radiation pressure and Lorentz force. The distribution of orbital elements is also analyzed.}, language = {en} } @misc{SpahnSachseSeissetal.2019, author = {Spahn, Frank and Sachse, Manuel and Seiss, Martin and Hsu, Hsiang-Wen and Kempf, Sascha and Horanyi, Mihaly}, title = {Circumplanetary Dust Populations}, series = {Space science reviews}, volume = {215}, journal = {Space science reviews}, number = {1}, publisher = {Springer}, address = {Dordrecht}, issn = {0038-6308}, doi = {10.1007/s11214-018-0577-3}, pages = {54}, year = {2019}, abstract = {We summarize the current state of observations of circumplanetary dust populations, including both dilute and dense rings and tori around the giant planets, ejecta clouds engulfing airless moons, and rings around smaller planetary bodies throughout the Solar System. We also discuss the theoretical models that enable these observations to be understood in terms of the sources, sinks and transport of various dust populations. The dynamics and resulting transport of the particles can be quite complex, due to the fact that their motion is influenced by neutral and plasma drag, radiation pressure, and electromagnetic forcesall in addition to gravity. The relative importance of these forces depends on the environment, as well as the makeup and size of the particles. Possible dust sources include the generation of ejecta particles by impacts, active volcanoes and geysers, and the capture of exogenous particles. Possible dust sinks include collisions with moons, rings, or the central planet, erosion due to sublimation and sputtering, even ejection and escape from the circumplanetary environment.}, language = {en} }