The case dates to the 1840s, when telegraph networks began transforming long-distance communication. As these early electrical systems expanded, operators sometimes experienced unexplained failures that disrupted equipment. Scientists now understand that some of these problems were caused by changes in Earth’s magnetic field driven by solar activity.

Researchers led by Lancaster University revisited historical accounts of solar activity interfering with railway telegraph systems and delaying trains in Exeter, England. The study involved scientists from RMIT University, the British Geological Survey, Natural Resources Canada, Baylor University and the UK’s National Institute for Space Research, RAL Space.

By combining historical documents with scientific observations, the team identified an error that changed the timeline of one of the earliest recorded technological disruptions caused by space weather.

How Solar Storms First Disrupted Technology

One of the most dramatic historical examples of space weather affecting technology occurred in 1859. Known as the Carrington Event, this powerful solar storm included a massive solar flare and a coronal mass ejection—a huge eruption of charged particles and magnetic fields from the Sun.

The resulting geomagnetic disturbance produced spectacular auroras that were visible as far south as Hawaii and Central America. In some locations, the sky became so bright that people could read newspapers at night. The unusual illumination even led gold miners to believe morning had arrived, prompting them to begin preparing breakfast just after midnight.

The Carrington Event also disrupted telegraph networks around the world. Electrical surges caused equipment to malfunction, sent sparks flying from wires, shocked operators and triggered fires. In some cases, the induced current was strong enough for telegraph systems to operate without batteries.

The Carrington Event remains the best-known example from this period, but evidence that solar activity interfered with electrical systems dates back even further.

In 1871, an anonymous author published a report in Nature describing an “extremely strong magnetic disturbance” that was said to have occurred on October 18, 1841. According to the report, the disturbance disrupted Exeter’s railway signals and delayed a train scheduled to depart at 10:05 p.m. by 16 minutes.

If the date had been correct, the incident would have been the earliest known example of space weather disrupting human technology.

However, new findings published in the American Geophysical Union journal Space Weather revealed that the original account contained significant historical errors.

The Railway Error That Changed the History of Solar Storms

Associate Professor Brett Carter, a space weather researcher at RMIT University, helped examine the historical record. During the investigation, the researchers noticed a problem that immediately cast doubt on the original timeline.

The Exeter-to-Starcross railway line mentioned in the report probably did not open until 1846—almost five years after the alleged 1841 incident.

“This study effectively investigated what was supposed to be a typo in the 1871 Nature paper, and found that it was a typo because the Exeter to Starcross railway line mentioned in that paper did not exist until five years later, in 1846,” Carter said.

To determine when the train delay actually occurred, the researchers examined a broad range of historical evidence. They compared railway timetables and newspaper reports with observations of solar activity, descriptions of auroras and digitized measurements of Earth’s magnetic field.

Together, these records point to a different date: October 18, 1848—exactly seven years after the date given in the original report.

The revised chronology resolves the apparent contradictions and places the event at a critical moment in technological history, when telegraph and railway systems were becoming increasingly widespread.

Carter explained that the 1840s marked a turning point in humanity’s relationship with space weather. Solar disturbances had always occurred, but the rise of electrical technology made it possible for their effects to interfere directly with everyday activities.

“It’s important to understand this historical event because the 1840s marked a crossroads between the rise of the technological age and the ever-present space weather,” Carter said.

“Since we crossed this line, humanity has not looked back.”

The discovery also changes the event’s place in the historical record. Although the Exeter disruption remains one of the earliest reliable examples of space weather affecting technology, it can no longer be considered the first.

That distinction now belongs to a previously documented incident involving telegraph interference on the British Midland Railway in March 1847.

Why the 1848 Exeter Train Delay Matters

Professor Jim Wilde of Lancaster University, who led the study, said the findings show that space weather was affecting society long before the development of modern power grids, satellites and electronic communication networks.

“What this study highlights is that space weather is not a new threat, but a long-standing natural hazard. Society has been experiencing the effects of space weather on technology almost as long as electrical technology has existed,” Wilde said.

The Exeter incident is especially significant because it occurred when electrical technology was still in its infancy. Railway operators were beginning to depend on telegraph systems, creating new opportunities for solar disturbances to interfere with critical infrastructure.

“The Exeter train delay is an interesting story because it sits at the exact point when emerging technology was first beginning to encounter the realities of the space environment. By combining historical archives and scientific observations, we were able to show that this event almost certainly occurred in 1848 rather than 1841,” Wilde said.

“While this means this is not the oldest recorded space weather effect, it is still one of the first clear examples of solar activity disrupting critical infrastructure,” he added.

The research also demonstrates how historical scientific records can be combined with newspapers and other archival material to reconstruct events that occurred long before modern monitoring equipment existed.

“It also shows the value of combining scientific records with contemporary newspaper reports and archival documents when reconstructing historical space weather events,” Wilde said.

Dr. Mike Hapgood, a visiting researcher and space weather expert at Britain’s National Institute for Space Research, RAL Space, described the research process as similar to detective work.

“This highlights the importance of preserving these old records, which provide the evidence base needed to interpret past events and enhance future predictions,” he said.

Modern Technology Still Faces Solar Storm Risks

Almost two centuries after the Exeter train delay, solar storms continue to pose risks to railways and other vital infrastructure. Although the technology has changed dramatically, modern systems remain vulnerable to disturbances originating from the Sun.

Today, space weather can interfere with power systems, railway signaling equipment, satellite navigation and communication networks. Strong solar events can disturb Earth’s magnetic field, generate unwanted currents in infrastructure and affect systems that depend on reliable satellite signals.

Scientists now have far more advanced monitoring equipment and forecasting methods than they did in the 19th century. However, society’s growing reliance on interconnected electrical and space-based technologies is also creating new vulnerabilities.

Understanding how historical solar storms affected infrastructure can help researchers assess the risks posed by future events and develop better ways to reduce potential disruptions.

“Increasing our understanding of these events is essential to preparing for and mitigating the effects of space weather, especially as we look forward to an exciting decade of space exploration as we face the challenges of a new solar cycle in the 2030s,” Hapgood said.