Ejected Particles after Impact Splash on Mars: Electrification

TL;DR

This study investigates the electrification and charge distribution of particles ejected during saltation on Mars, revealing that ejected particles carry significant charges with a slight positive bias, which impacts Martian surface processes.

Contribution

It provides new experimental data on the charge characteristics of ejected Martian particles, focusing on electrification during impact splash in a controlled laboratory setting.

Findings

Ejected particles carry charges up to 10^5 elementary charges.

Particles show a bias towards positive charges within the size range.

Charge densities can exceed 10^7 e/mm^2.

Abstract

Within the RoadMap project we investigated the microphysical aspects of particle collisions during saltation on the Martian surface in laboratory experiments. Following the size distribution of ejected particles, their aerodynamic properties and aggregation status upon ejection, we now focus on the electrification and charge distribution of ejected particles. We analyzed rebound and ejection trajectories of grains in a vacuum setup with a strong electric field of 100 kV/m and deduced particle charges from their acceleration. The ejected particles have sizes of about 10 to 100 microns. They carry charges up to $10^5$ e or charge densities up to $> 10^7$ e/mm$^2$. Within the given size range, we find a small bias towards positive charges.