The solar storm gained momentum instead of slowing down — and scientists have finally figured out why

Scientists spent several years trying to figure out what had happened. The answer turned out to be unexpected: the storm had its own hidden engine operating within it.

The findings have been published in The Astrophysical Journal Letters.

Details

Solar eruptions are not just flashes of light. They are colossal clouds of magnetised gas that the Sun periodically shoots into space. They carry billions of tonnes of matter and twisted magnetic fields. It is precisely these eruptions that cause magnetic storms on Earth — the very ones that disrupt satellite operations and can knock out power grids.

Physicists usually describe the movement of such eruptions simply: a fast-moving one slows down, a slow-moving one speeds up, until both match the speed of the surrounding solar wind. Like a cork in water — sooner or later it goes with the flow.

The 2021 eruption broke this pattern. Two spacecraft — Solar Orbiter and Wind — caught it at different distances from the Sun and recorded that between the two observation points, the storm did not slow down but actually gained speed. No standard models could explain this. In one of them, researchers even had to manually add a mysterious ‘additional force’ — simply to make the results match.

The answer came when scientists looked inside the storm itself. The eruption was a so-called magnetic filament — a tight tangle of twisted magnetic fields. As the storm hurtled through space, this tangle began to unravel and tear apart. The organised structure broke down, turning into chaotic turbulence.

And this is where the unexpected happened. Usually, turbulence heats the gas — the energy of chaos is converted into heat. But in this outburst, the plasma, on the contrary, was cooling faster than it should have been. This meant that the energy was going somewhere else. Scientists figured out where: the turbulence was pressing on the cloud from within and pushing it forward. The storm was literally accelerating itself — through its own internal breakdown.

Why this matters

Until now, space weather models have viewed solar eruptions from the outside — as a cloud simply drifting in the solar wind. This research shows that there may be a completely different dynamic at play inside the storm, and that this affects when and with what force the eruption will reach Earth.

This has practical implications. Solar storms can damage satellites, disrupt GPS, interfere with radio communications and, in extreme cases, overload power grids. The more accurate the forecast, the more time operators have to protect equipment and warn astronauts in orbit.

For now, we are talking about a single event, and the scientists themselves emphasise that there is a lot of work ahead to test the model against other eruptions. But the direction has been set.

Background

Predicting solar storms has been one of the main challenges in space physics over the last few decades. This became particularly pressing after 1989, when a powerful magnetic storm left the Canadian province of Quebec without power for nine hours. Since then, researchers have been looking for ways to predict such events several hours or days in advance.

The standard model — the so-called aerodynamic drag model — was long considered reliable enough for most cases. But it describes the eruption as a passive cloud, without taking into account what is happening inside. New research shows that this simplification may be misleading — at least for some storms.

The Sun is currently near the peak of its 11-year activity cycle, meaning that flares and eruptions will occur more frequently in the coming years. This makes accurate forecasting models particularly relevant.

Source

Daniele Telloni et al., Disentangling the Anomalous Acceleration of Coronal Mass Ejections via Turbulent Energy Conversion, The Astrophysical Journal Letters (2026).