Stability of charge and orbit of dust in the solar system

Dust in space is formed due to the activity of comets or erosion and collisions of asteroids in the solar system. Astronomical observations of the night sky indirectly reveal, through the reflection of the solar light, the presence of dust in the zodiac along the ecliptic during dusk. Space technology nowadays offers the big chance to analyze the composition of dust in situ, while studies of space dust in the atmosphere or within core samples existed already before. There are many uncharted dust clouds in interplanetary space and their evolution in interplanetary space is currently poorly understood. Impacts of space dust can destroy spacecraft or lead to erosion and damage of critical parts of it. The sensitivity of scientific experiments also strongly depends on the dust environment. It is therefore crucial to understand the movement of dust clouds in interplanetary space. The motion of interplanetary dust is the result of the complex interplay of various forces. The motion turns out to be chaotic and the final fate of space dust once formed at specific locations in the solar system is thus uncertain. It is the purpose of our study to find suitable conditions that support the presence of dust at different locations in the solar system for long times in order to predict the regions in the solar system with increased dust densities. For this reason we are looking for special sets of physical parameters that allow orbital motion of charged dust to resist perturbations due to additional forces. The role of the charge over mass ratio of dust grains has not yet been investigated by the scientific community in full detail. It is either usually neglected or assumed to be constant. The novelty of our approach is to take also the charge variations of space dust into account. Our study requires the careful derivation of new mathematical models describing the problems under investigation and the implementation of new and state of the art analytical and numerical techniques. As a result we are able to predict the correct charge over mass ratios of space dust that will stay in the vicinity of its origin of formation. To reach this scientific goal it is necessary to model the orbital motion, the charge history of the particle, as well as the interplanetary magnetic field. Therefore, this cross-disciplinary study also requires a link between celestial mechanics and plasma physics. The one, to model the orbital dynamics, the other to model the dynamics of charge and the interplanetary magnetic field.

This project is funded by the Austrian FWF project P30542.