
History’s greatest solar storm
Extreme solar storms such as the 1859 Carrington Event can play havoc with technology on Earth
The Carrington Event was a large solar storm that took place at the beginning of September 1859, just a few months before the solar maximum of 1860.
In August 1859, astronomers around the world watched with fascination as the number of sunspots on the solar disk grew. Among them was Richard Carrington, an amateur skywatcher in a small town called Redhill, near London in England.
The flare was a major coronal mass ejection (CME), a burst of magnetized plasma from the sun‘s upper atmosphere, the corona. In 17.6 hours, the CME traversed over 90 million miles (150 million km) between the sun and Earth and unleashed its force on our planet. According to NASA spaceflight, it usually takes CMEs multiple days to reach Earth.
The day after Carrington observed the impressive flare, Earth experienced an unprecedented geomagnetic storm, with telegraph systems going haywire and auroral displays — normally confined to polar latitudes — visible in the tropics, according to NASA Science.
Carrington put two and two together and realized that the solar flare he’d seen was almost certainly the cause of this massive geomagnetic disturbance. This was a connection that had never previously been made, according to NASA Spaceflight. The solar storm of 1859 is now known as the Carrington Event in his honor.