Impact-generated dust clouds around planetary satellites: asymmetry effects

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

10

Scientific paper

In a companion paper (Krivov et al., Impact-generated dust clouds around planetary satellites: spherically symmetric case, Planet. Space. Sci. 2003, 51, 251-269) an analytic model of an impact-generated, steady-state, spherically symmetric dust cloud around an atmosphereless planetary satellite (or planet-Mercury, Pluto) has been developed. This paper lifts the assumption of spherical symmetry and focuses on the asymmetry effects that result from the motion of the parent body through an isotropic field of impactors. As in the spherically symmetric case, we first consider the dust production from the surface and then derive a general phase-space distribution function of the ensemble of ejected dust motes. All quantities of interest, such as particle number densities and fluxes, can be obtained by integrating this phase-space distribution function.
As an example, we calculate an asymmetric distribution of dust number density in a cloud. It is found that the deviation from the symmetric case can be accurately described by a cosine function of the colatitude measured from the apex of the satellite motion. This property of the asymmetry is rather robust. It is shown that even an extremely asymmetric dust production at the surface, when nearly all dust is ejected from the leading hemisphere, turns rapidly into the cosine modulation of the number density at distances larger than a few satellite radii. The amplitude of the modulation depends on the ratio of the moon orbital velocity to the speed of impactors and on the initial angular distribution of the ejecta. Furthermore, regardless of the functional form of the initial angular distribution, the number density distribution of the dust cloud is only sensitive to the mean ejecta angle. When the mean angle is small-ejection close to the normal of the surface-the initial dust production asymmetry remains persistent even far from the satellite, but when this angle is larger than about /45°, the asymmetry coefficient drops very rapidly with the increasing distance. The dependence of the asymmetric number density on other parameters is very weak.
On the whole, our results provide necessary theoretical guidelines for a dedicated quest of asymmetries in the dust detector data, both those obtained by the Galileo dust detector around the Galilean satellites of Jupiter and those expected from the Cassini dust experiment around outer Saturnian moons.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Impact-generated dust clouds around planetary satellites: asymmetry effects does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Impact-generated dust clouds around planetary satellites: asymmetry effects, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Impact-generated dust clouds around planetary satellites: asymmetry effects will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1534425

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.