Mars as a comet: Solar wind interaction on a large scale

TL;DR

This study models Mars-solar wind interactions on a large scale, revealing how Mars influences solar wind flow and ion escape patterns, similar to cometary interactions, with distinct ion populations and escape behaviors.

Contribution

It introduces a hybrid modeling approach to analyze large-scale Mars-solar wind interactions, highlighting ion escape dynamics beyond the near-planet region.

Findings

Solar wind disturbed up to 100 Mars radii downstream.

Identification of two ion populations: polar plume and fluid outflow.

Ion escape rate increases linearly with production then saturates.

Abstract

Looking at the Mars-solar wind interaction on a larger spatial scale than the near Mars region, the planet can be seen as an ion source interacting with the solar wind, in many ways like a comet, but with a smaller ion source region. Here we study the interaction between Mars and the solar wind using a hybrid model (particle ions and fluid electrons). We find that the solar wind is disturbed by Mars out to 100 Mars radii downstream of the planet, and beyond. On this large scale it is clear that the escaping ions can be classified into two different populations. A polar plume of ions picked-up by the solar wind, and a more fluid outflow of ions behind the planet. The outflow increases linear with the production up to levels of observed outflow rates, then the escape levels off for higher production rates.