Researchers have revisited the history of one of the earliest known cases in which solar activity disrupted electrical infrastructure. In 1871, the journal Nature published an account of a train delay in Exeter, England, caused by a magnetic storm said to have occurred in 1841. However, the railway line mentioned in the publication did not open until five years later. After studying archival records, scientists determined that the incident took place on October 18, 1848.

The work of an international team of researchers led by specialists from Lancaster University was published in the journal Space Weather. It not only corrects a long-standing dating error but also refines the history of space weather’s impact on technology.

The train was delayed because of a telegraph failure

In the 19th century, railways and the electric telegraph were rapidly transforming travel and the transmission of information. But this new infrastructure proved vulnerable to what is now called space weather: solar activity can alter Earth’s magnetic field and create interference in electrical systems.

According to a note published in Nature in 1871, on October 18, 1841, a strong magnetic disturbance disrupted railway signals in Exeter. As a result, the departure of a train scheduled for 22:05 was delayed by 16 minutes.

If the date had been correct, this case could have been considered the earliest known example of space weather affecting human technology.

But researchers found a discrepancy: the railway line between Exeter and Starcross mentioned in the note only began operating in 1846. Therefore, the described event could not have happened in 1841.

Archives helped establish the correct date

To determine when the incident occurred, scientists compared historical train timetables, newspaper reports, eyewitness accounts of auroras, and digitized measurements of Earth’s magnetic field. The study involved specialists from the United Kingdom, Australia, Canada, and the United States, including staff from the British Geological Survey and the UK national space laboratory RAL Space.

The body of evidence pointed to a different date — October 18, 1848, exactly seven years later than the one given in the Nature publication.

According to Associate Professor Brett Carter of RMIT University, the researchers were essentially investigating a typo in a 19th-century scientific article. The error seemed minor, but it changed the chronology of the early cases of solar activity affecting technology.

At the same time, the corrected date does not make the episode the earliest known case of its kind. That distinction now belongs to an earlier documented incident: interference with telegraph operations on the Midland Railway in March 1847.

From the 19th-century telegraph to modern power systems

The best-known historical example of extreme space weather remains the Carrington Event of 1859. At that time, a powerful solar storm produced vivid auroras that were observed even in regions far south of polar latitudes. At the same time, telegraph networks around the world experienced serious disruptions: equipment failed, wires sparked, operators received electric shocks, and in some cases fires broke out. In some situations, telegraphs continued operating even after their batteries were disconnected — thanks to electric currents induced by the storm.

However, the Exeter case shows that solar activity began affecting the day-to-day operation of electrical infrastructure even before the Carrington Event.

The study’s lead author, Lancaster University professor Jim Wild, notes that space weather poses a threat not only to modern technologies: society has been dealing with its consequences for almost as long as it has used electrical systems.

Today, severe solar storms can disrupt power grids, railway signaling, satellite navigation, and communications systems. Changes in Earth’s magnetic field can induce unwanted electrical currents in infrastructure, while disruptions to satellite signals can affect navigation and other critical services.

Why old records matter for forecasting

Modern scientists have far more advanced tools for observing the Sun and Earth’s magnetic field than researchers in the 19th century did. But historical evidence helps us understand how space weather affected technology before the advent of modern measurement systems.

According to space weather specialist Mike Hapgood of RAL Space, preserving old archives makes it possible to reconstruct past events and create a more reliable basis for assessing future risks.

This is especially important against the backdrop of society’s growing dependence on power grids, satellites, and interconnected digital systems. The more critical processes depend on technology, the more serious the consequences of a major solar storm could be.

The study does not change the physics of solar storms, but it corrects the historical chronology and shows how useful a combination of scientific measurements, newspaper reports, and archival documents can be. Sometimes, to better understand the threats of the future, scientists first have to unravel a mistake made nearly two centuries ago.