While their differences can make it tricky to compare planets directly, understanding how solar activity impacts the residents of the Solar System – in other words, space weather forecasting – is hugely important. At Earth, solar storms can be dangerous and damaging for astronauts and equipment up in space, and can disrupt our satellites and systems (power, radio, navigation) further down.

However, studying space weather is difficult as the Sun throws out radiation and material erratically, making targeted measurements largely opportunistic. “Fortunately, we were able to use this new technique with Mars Express and TGO just 10 minutes after a large solar flare hit Mars. Currently we’re only performing two observations per week at Mars, so the timing was extremely lucky,” adds Jacob.

Jacob and colleagues captured the aftermath of three solar events – all part of the same storm, but different in terms of what they throw out into space, and how they do it: one flare of radiation, one burst of high-energy particles, and an eruption of material known as a coronal mass ejection (CME).

Together, these events sent fast-moving, energetic, magnetised plasma and X-rays flooding towards Mars. When this barrage of material hit the planet’s upper atmosphere it collided with neutral atoms and stripped away their electrons, causing the region to fill up with electrons and charged particles.