In July 1982, train signals in Sweden misfired and accidentally turned red. Believe it or not, the culprit was a cosmic storm that started 150 million kilometers (93 million miles) away. Explosive events on the Sun can disrupt Earth’s magnetic field. They send out enormous amounts of magnetized solar material blasting towards Earth. A cosmic storm or geomagnetic storm occurs when this material disrupts our planet’s magnetic field. This disturbance causes power lines, pipelines, railway lines, etc., on the Earth’s surface. may cause electrical currents that may disrupt

Train disruptions are particularly troublesome, as space storms can disrupt detection systems that prevent collisions. Railroads detect trains using electric current and send stop signals to others to prevent accidents. But when Earth’s magnetic field is disrupted, it can send false signals to stop or go, affecting operations and potentially putting cargo and passengers on board in danger.

CJ Patterson and colleagues developed a model to test how strong a geomagnetic storm must be to disrupt rail operations and how often this can occur. The model, which simulates the effects of space storms on electrical signals, is based on two real UK rail lines with different directions and geographies. The findings were published in the journal Space Weather.

They found that along both simulated lines, a cosmic storm strong enough to disrupt a railroad signal occurs approximately every 30 years. More severe storms, expected to occur every 100 years, disrupted nearly all signals on both lines. The findings could help scientists and regulators assess how vulnerable trains are to space-based geomagnetic disturbances and raise awareness among operators.