Introduction

The dynamics of dust, submillimeter-sized dust grains, are a fascinating area of study of our Solar System's dynamical evolution. Small particles, especially charged particles, respond to forces other than gravitational, in particular, electromagnetic forces. The dust particle's properties and dynamics fall into a complex regime between nuclear physics and electromagnetic physics and gravitational physics. In order to calculate charges on a dust particle around a planet, we must characterize:

• The planet's magnetospheric features: its magnetic field and plasma,

• The physical processes onto the dust particle that generate currents, and

• The material properties of the dust particle.

In this paper, we make reference to results of charging of dust particles in Earth's magnetosphere [1][2]. Earth is an interesting charging environment for dust particles, in part, because the dynamic magnetospheric plasma shows steep changes in the electron and ion energies and densities, therefore, the electron energy can be quite high (e.g. a few thousand eV). Table 1 lists some basic parameters comparing Saturn's and Earth's magnetosphere.

Table 1

Basic parameters of Saturn's and Earth's magnetosphere

Parameters

Saturn

Earth

Rotation Period (day) Dipole Moment (Gauss cm3) Field at Equator (Gauss) Dipole Axis (deg) Magnetopause Distance Plasma Source

Solar Wind, Atmosphere, Solar Wind, Atmosphere Rings, Moons

Table 2

Saturn plasma representative numbers

Component Location (Rs) Energy (eV) Density (cm 3) Debye Length (m)

Cold electrons Hot electrons Hydrogen ions Oxygen ions

Was this article helpful?

0 0

Post a comment