"Your train has been delayed due to a signalling failure" is a phrase commuters will be all too familiar with.

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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.

A red light indicates the presence of a train on the track, or could it be space weather interference? Photo by John Keeble/Getty Images)
A red light indicates the presence of a train on the track, or could it be space weather interference? Photo by John Keeble/Getty Images)

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!"

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www.lancaster.ac.uk

Authors

Elizabeth Pearson
Ezzy PearsonScience journalist

Ezzy Pearson is the Features Editor of BBC Sky at Night Magazine. Her first book about the history of robotic planetary landers is out now from The History Press.