Scientists solve 1840s space weather mystery

What happened

19th century Nature account of 1841 train delayed by geomagnetic storm got year wrong—due to a typo. The infamous Carrington Event of 1859 has long been considered the first extreme space weather event, but there have been reports of minor disturbances to telegraph equipment during geomagnetic storms since the late 1840s.

If accurate, this would be the earliest such account. The Carrington Event remains the most powerful geomagnetic storm in the scientific record, with strong auroral displays occurring all over the world, causing sparking and even a few fires in telegraph stations.

Some of the auroras were so bright that people reported being able to read the newspaper by their light. The telegraph was a relatively new technology at the time, having first emerged in the 1830s, and the geomagnetically induced current—from a likely coronal mass injection from the Sun—knocked out telegraph systems.