Solar superstorm gave ESA's Mars orbiters a handy science opportunity

Almost two years ago, a solar storm hit Earth, triggering auroras that were seen as far south as Mexico. The storm also reached Mars and was detected by a pair of ESA spacecraft, Mars Express and ExoMars Trace Gas Orbiter (TGO).

The storm caused computer errors on both spacecraft – "a typical peril of space weather, as the particles involved are so energetic and hard to predict," said ESA Research Fellow Jacob Parrott. "Luckily, the spacecraft were designed with this in mind, and built with radiation-resistant components and specific systems for detecting and fixing these errors. They recovered fast."

However, the storm also presented opportunities, and using radio occultation, scientists were able to investigate its impact on Mars.

Mars Express beamed a radio signal to TGO just as the latter was vanishing over the Martian horizon. As TGO vanished, the radio signal was refracted by the layers ...