"Your train has been delayed due to a signalling failure" is a phrase commuters will be all too familiar with.
While most of us might lay the blame on snow or rain, a recent report suggests another type of weather could also be at fault:– space weather, in the form of ejections from the Sun interacting with Earth's magnetic field.
Train signalling systems use electric currents in the rails to determine if a train is present on a given section of track, showing a red light if it detects one.
However, solar storms also cause similar currents to form in the rails and it only takes a moderate event to trigger a red signal, even when there’s no train present.
"We are now working on looking at the case where trains are present on the line, and how strong a solar storm needs to be to turn a red signal back to green," says Cameron Patterson from Lancaster University, who investigated the phenomenon.
"That’s a far more hazardous scenario, potentially leading to crashes!"
