@article{MakuchBrilliantovSremcevicetal.2006, author = {Makuch, Martin and Brilliantov, Nikolai V. and Sremcevic, Miodrag and Spahn, Frank and Krivov, Alexander V.}, title = {Stochastic circumplanetary dynamics of rotating non-spherical dust particles}, series = {Planetary and space science}, volume = {54}, journal = {Planetary and space science}, number = {9-10}, publisher = {Elsevier}, address = {Oxford}, issn = {0032-0633}, doi = {10.1016/j.pss.2006.05.006}, pages = {855 -- 870}, year = {2006}, abstract = {We develop a model of stochastic radiation pressure for rotating non-spherical particles and apply the model to circumplanetary dynamics of dust grains. The stochastic properties of the radiation pressure are related to the ensemble-averaged characteristics of the rotating particles, which are given in terms of the rotational time-correlation function of a grain. We investigate the model analytically and show that an ensemble of particle trajectories demonstrates a diffusion-like behaviour. The analytical results are compared with numerical simulations, performed for the motion of the dusty ejecta from Deimos in orbit around Mars. We find that the theoretical predictions are in a good agreement with the simulation results. The agreement however deteriorates at later time, when the impact of non-linear terms, neglected in the analytic approach, becomes significant. Our results indicate that the stochastic modulation of the radiation pressure can play an important role in the circumplanetary dynamics of dust and may in case of some dusty systems noticeably alter an optical depth. (c) 2006 Elsevier Ltd. All rights reserved.}, language = {en} } @article{MakuchKrivovSpahn2005, author = {Makuch, Martin and Krivov, Alexander V. and Spahn, Frank}, title = {Long-term dynamical evolution of dusty ejecta from Deimos}, issn = {0032-0633}, year = {2005}, abstract = {We re-assess expected properties of the presumed dust belt of Mars formed by impact ejecta from Deimos. Previous studies have shown that dynamics of Deimos particles are dominated by two perturbing forces: radiation pressure (RP) and Mars' oblateness (J2). At the same time, they have demonstrated that lifetimes of particles, especially of grains about ten of micrometers in size, may reach more than 10(4) years. On such timescales, the Poynting-Robertson drag (PR) becomes important. Here we provide a study of the dynamics under the combined action of all three perturbing forces. We show that a PR decay of the semimajor axes leads to an adiabatic decrease of amplitudes and periods of oscillations in orbital inclinations predicted in the framework of the underlying RP+J2 problem. Furthermore, we show that smallest of the long-lived Deimos grains (radius approximate to 5-10 mum) may reach a chaotic regime, resulting in unpredictable and abrupt changes of their dynamics. The particles just above that size (approximate to 10- 15 mum) should be the most abundant in the Deimos torus. Our dynamical analysis, combined with a more accurate study of the particle lifetimes, provides corrections to earlier predictions about the dimensions and geometry of the Deimos torus. In addition to a population, appreciably inclined and shifted towards the Sun, the torus should contain a more contracted, less asymmetric, and less tilted component between the orbits of Phobos and Deimos. (C) 2004 Elsevier Ltd. All rights reserved}, language = {en} } @article{SpahnSchmidtAlbersetal.2006, author = {Spahn, Frank and Schmidt, J{\"u}rgen and Albers, Nicole and H{\"o}rning, Marcel and Makuch, Martin and Seiß, Martin and Kempf, Sascha and Srama, Ralf and Dikarev, Valeri and Helfert, Stefan and Moragas-Klostermeyer, Georg and Krivov, Alexander V. and Sremcevic, Miodrag and Tuzzolino, Anthony J. and Economou, Thanasis and Gr{\"u}n, Eberhard}, title = {Cassini dust measurements at Enceladus and implications for the origin of the E ring}, doi = {10.1126/science.1121375}, year = {2006}, language = {en} } @phdthesis{Makuch2007, author = {Makuch, Martin}, title = {Circumplanetary dust dynamics : application to Martian dust tori and Enceladus dust plumes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-14404}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {Our Solar system contains a large amount of dust, containing valuable information about our close cosmic environment. If created in a planet's system, the particles stay predominantly in its vicinity and can form extended dust envelopes, tori or rings around them. A fascinating example of these complexes are Saturnian rings containing a wide range of particles sizes from house-size objects in the main rings up to micron-sized grains constituting the E ring. Other example are ring systems in general, containing a large fraction of dust or also the putative dust-tori surrounding the planet Mars. The dynamical life'' of such circumplanetary dust populations is the main subject of our study. In this thesis a general model of creation, dynamics and death'' of circumplanetary dust is developed. Endogenic and exogenic processes creating dust at atmosphereless bodies are presented. Then, we describe the main forces influencing the particle dynamics and study dynamical responses induced by stochastic fluctuations. In order to estimate the properties of steady-state population of considered dust complex, the grain mean lifetime as a result of a balance of dust creation, life'' and loss mechanisms is determined. The latter strongly depends on the surrounding environment, the particle properties and its dynamical history. The presented model can be readily applied to study any circumplanetary dust complex. As an example we study dynamics of two dust populations in the Solar system. First we explore the dynamics of particles, ejected from Martian moon Deimos by impacts of micrometeoroids, which should form a putative tori along the orbit of the moon. The long-term influence of indirect component of radiation pressure, the Poynting-Robertson drag gives rise in significant change of torus geometry. Furthermore, the action of radiation pressure on rotating non-spherical dust particles results in stochastic dispersion of initially confined ensemble of particles, which causes decrease of particle number densities and corresponding optical depth of the torus. Second, we investigate the dust dynamics in the vicinity of Saturnian moon Enceladus. During three flybys of the Cassini spacecraft with Enceladus, the on-board dust detector registered a micron-sized dust population around the moon. Surprisingly, the peak of the measured impact rate occurred 1 minute before the closest approach of the spacecraft to the moon. This asymmetry of the measured rate can be associated with locally enhanced dust production near Enceladus south pole. Other Cassini instruments also detected evidence of geophysical activity in the south polar region of the moon: high surface temperature and extended plumes of gas and dust leaving the surface. Comparison of our results with this in situ measurements reveals that the south polar ejecta may provide the dominant source of particles sustaining the Saturn's E ring.}, language = {en} }