Solar wind creates giant waves that fling Mars' atmosphere into space

Researchers have identified massive Kelvin-Helmholtz waves at the edge of Mars' upper atmosphere that accelerate atmospheric particles into space, a process driven by the solar wind.

A new investigation by Boston University researchers reveals that the solar wind induces giant Kelvin-Helmholtz waves at the top of Mars' atmosphere, stirring the gas into massive plasma clouds that escape into space. Data from NASA's MAVEN spacecraft, which measured escaping ions, and China's Tianwen-1 probe, which recorded upstream solar-wind conditions, allowed the team to directly correlate wind variations with atmospheric loss.

The study finds that these wave-driven escape events are concentrated on a single hemisphere, governed by the direction of the solar-wind electric field. The findings suggest that such wave activity played a major role in stripping Mars of its once thicker, potentially life-supporting atmosphere. Future work will aim to determine the conditions that favor wave formation and quantify their overall contribution, with upcoming missions like NASA's ESCAPADE expected to provide further insight. The research also hints that similar processes could affect other unmagnetized worlds, including certain exoplanets.