The influence of mass loss on the dynamics of dust near the Sun

Abstract

The Parker Solar Probe (PSP) mission by NASA and the Solar Orbiter (SolO) mission by ESA are two recently launched missions that measure dust in the inner solar system. The dust is produced by fragmentation of meteoroids, which are large fragments of the asteroids and comets. The dust particles are small enough that their motion is affected by the radiation pressure force from the Sun. Dust fragments that are ejected from the solar system by this force are referred to as 𝛽-meteoroids, and initial data analysis shows that their impacts are measured by the PSP and SolO spacecraft (Szalay et al. (2020), Zaslavsky et al. (2021)). In the harsh space environment of the inner solar system, the dust grains may experience mass loss along their trajectories due to sublimation, sputtering and collisions with other dust grains. This thesis investigates the influence of the mass loss on the dynamics of dust in the inner solar system, in view of the PSP and SolO missions. The dust sizes at which the sputtering process is of importance is identified, and orbital calculations are performed to evaluate the effect of sputtering on the orbits of dust with low and high eccentricities. The dust in the inner solar system that is measured by PSP and SolO is so far assumed to be either dust in near circular, bound orbits or 𝛽-meteoroids. Based on the calculations performed in this thesis, a third dust component is predicted. This is dust in highly elliptical orbits that are significantly affected by sputtering. It is likely that the ongoing missions may identify this component, and so it is proposed for future work to calculate in detail the flux rate of these dust grains onto the PSP and SolO. The presented calculations show that in general the sputtering is an important process of mass loss for dust at distances between 0.1 and 1 AU from the Sun and that this mass loss changes perihelia and aphelia of the dust orbits. The influence of sputtering on the mass of 𝛽-meteoroids is however small and it is reasonable to assume that 𝛽-meteoroids have a constant mass.