@article{OttoJaumannKrohnetal.2016,
  author    = {Otto, Katharina Alexandra and Jaumann, R. and Krohn, K. and Spahn, Frank and Raymond, C. A. and Russell, C. T.},
  title     = {The Coriolis effect on mass wasting during the Rheasilvia impact on asteroid Vesta},
  series = {Geophysical research letters},
  volume    = {43},
  journal   = {Geophysical research letters},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {0094-8276},
  doi       = {10.1002/2016GL071539},
  pages     = {12340 -- 12347},
  year      = {2016},
  abstract  = {We investigate the influence of the Coriolis force on mass motion related to the Rheasilvia impact on asteroid Vesta. Observations by the NASA Dawn mission revealed a pattern of curved radial ridges, which are related to Coriolis-deflected mass-wasting during the initial modification stage of the crater. Utilizing the projected curvature of the mass-wasting trajectories, we developed a method that enabled investigation of the initial mass wasting of the Rheasilvia impact by observational means. We demonstrate that the Coriolis force can strongly affect the crater formation processes on rapidly rotating objects, and we derive the material's velocities (28.9 ± 22.5 m/s), viscosities (1.5-9.0 × 106 Pa s) and coefficients of friction (0.02-0.81) during the impact modification stage. The duration of the impact modification stage could be estimated to (1.1 ± 0.5) h. By analyzing the velocity distribution with respect to the topography, we deduce that the Rheasilvia impactor hit a heterogeneous target and that the initial crater walls were significantly steeper during the modification stage.},
  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}
}
@article{DzhanoevSchmidtLiuetal.2016,
  author    = {Dzhanoev, Arsen R. and Schmidt, J. and Liu, X. and Spahn, Frank},
  title     = {Charging of small grains in a space plasma: Application to Jovian stream particles},
  series = {International psychogeriatrics},
  volume    = {591},
  journal   = {International psychogeriatrics},
  publisher = {EDP Sciences},
  address   = {Les Ulis},
  issn      = {1432-0746},
  doi       = {10.1051/0004-6361/201527891},
  pages     = {647 -- 684},
  year      = {2016},
  abstract  = {Context. Most theoretical investigations of dust charging processes in space have treated the current balance condition as independent of grain size. However, for small grains, since they are often observed in space environments, a dependence on grain size is expected owing to secondary electron emission (SEE). Here, by the term "small" we mean a particle size comparable to the typical penetration depth for given primary electron energy. The results are relevant for the dynamics of small, charged dust particles emitted by the volcanic moon Io, which forms the Jovian dust streams. Aims. We revise the theory of charging of small (submicron sized) micrometeoroids to take into account a high production of secondary electrons for small grains immersed in an isotropic flux of electrons. We apply our model to obtain an improved estimate for the charge of the dust streams leaving the Jovian system, detected by several spacecraft. Methods. We apply a continuum model to describe the penetration of primary electrons in a grain and the emission of secondary electrons along the path. Averaging over an isotropic flux of primaries, we derive a new expression for the secondary electron yield, which can be used to express the secondary electron current on a grain. Results. For the Jupiter plasma environment we derive the surface potential of grains composed of NaCl (believed to be the major constituent of Jovian dust stream particles) or silicates. For small particles, the potential depends on grain size and the secondary electron current induces a sensitivity to material properties. As a result of the small particle effect, the estimates for the charging times and for the fractional charge fluctuations of NaCl grains obtained using our general approach to SEE give results qualitatively different from the analogous estimates derived from the traditional approach to SEE. We find that for the charging environment considered in this paper field emission does not limit the charging of NaCl grains.},
  language  = {en}
}