THIRUVANANTHAPURAM: Forgotten records from the Thiruvananthapuram Astronomical Observatory have shed new light on the world's most powerful recorded solar storm, with potential implications for modern-day space-weather forecasting and satellite protection.
Preserved in Scotland for more than 160 years, the records suggest that the solar storm of 1859, known as the Carrington Event, was part of a sequence of powerful solar eruptions that repeatedly disturbed Earth's magnetic field.
The observatory, established in 1837 by the erstwhile Travancore Kingdom, now functions under the University of Kerala. The findings, by Prof R Jayakrishnan, Fazil C K and A Ajesh, have been published in the international journal ‘Astrophysics and Space Science’.
The researchers say the recovered records demonstrate how historical observations can contribute to contemporary understanding of extreme space-weather events and their potential impact on
modern technology.
The Carrington Event, which occurred on September 2, 1859, is considered the most intense solar storm ever documented. Analysis of the observatory records shows that Earth was hit by a series of coronal mass ejections, huge bursts of solar material, between August 14 and September 15 that year.
According to the researchers, the repeated impacts weakened Earth's magnetic field, allowing the September 2 storm to strike with extraordinary force. The geomagnetic field also remained disturbed for weeks afterwards.
"This is the first report worldwide to establish such a sequence," Prof Jayakrishnan said.
The findings, he said, compel scientists to rethink space weather as interconnected chains of solar activity rather than isolated events. The records themselves have a remarkable history.
John Allan Broun, who was Director of the observatory in the 19th century, carried the bifilar magnetometer sheets to Scotland after his retirement in the 1870s.
In the 1990s, the collection was moved to the Royal Society of Edinburgh and, in 2010, to the National Library of Scotland. Prof Jayakrishnan, the present Director, retraced the archival trail and uncovered the records.
The rediscovery gained further momentum after Dr Anna Szoula, an anthropologist from Jagiellonian University, Poland, visited the observatory in April 2025. She later joined Prof Jayakrishnan in Scotland to recover and digitise the material, scanning more than 7,000 documents over 10 days.
The researchers say the findings underline the importance of historical scientific records in understanding successive solar eruptions and their geomagnetic consequences, with implications for modern forecasting, satellite protection and global preparedness.
