The Great Geomagnetic Storm of September 1859: A look at the solar event that caused worldwide electrical disruptions

By Andrew McCoy and Fred Sargent | Sep 15, 2023
Getty Images / Veronika Oliinyk

Every electrical lineworker deserves to know the story of the Carrington Event of 1859.






Every electrical lineworker deserves to know the story of the Carrington Event of 1859.

In September 1859, a coronal mass ejection—a shower of plasma and magnetic fields ejected from the sun—collided with Earth’s magnetosphere, the magnetic bubble high above us that protects our atmosphere from being blown away by the solar winds and shields our planet from solar and other sources of radiation from outer space. 

It disastrously disrupted the world’s telegraph networks, which were the only full-scale “electrical” systems in existence. It was the most intense geomagnetic storm in recorded history. 

If a coronal mass ejection of this magnitude happened today, it would damage or even completely destroy electrical systems around the globe, including power generation and transmission and distribution, resulting in blackouts and other disruptions to electrical service. 

Be aware that there is always a chance it could happen again. Indeed, a smaller but significant version hit Earth as recently as August 2003. In 2012, a Carrington-size coronal mass ejection hurled from the sun and narrowly missed Earth as it passed.

A little history

The Carrington Event was named for Richard Carrington, an amateur astronomer who was the first to theorize and explain what had happened. ­He connected sunspots, solar flares and other ­occurrences over a century before “coronal mass ejection” became part of scientific terminology.

Carrington, heir to a prosperous brewery business in England in the mid-19th century, preferred to devote his time and attention not to beer-making, but to astronomy. He built a country mansion for himself with a customized design that incorporated a separate wing for a private observatory with a high-powered telescope. In a short number of years, he gained respect and recognition from the British Royal Astronomical Society for his relentless efforts at cataloging 3,735 stars and his special interest in studying and sketching sunspots. 

At his country mansion, Richard Carrington built an observatory equipped with one of the finest telescopes as the best way to pursue his passion for astronomy. | Wikimedia Commons

At his country mansion, Richard Carrington built an observatory equipped with one of the finest telescopes as the best way to pursue his passion for astronomy.Wikimedia Commons

In 1859, after six years of dutifully recording solar activities every day, his efforts paid off. Late on the morning of Sept. 1, Carrington was using his telescope to project the dark images of sunspots onto a drawing board that he had precisely positioned to sketch reflections of the sun. For a few fleeting minutes, he was stunned to discover mysterious bright white flashes superimposed on top of the sunspots. 

He became the first person ever to witness and record solar flares. Traveling at the speed of light (186,000 miles per second) from the surface of the sun 93 million miles away, the short-lived bright flashes took nine minutes to reach Carrington’s drawing board.

Seventeen hours later, lagging behind at merely 1,500 miles per second, the plasma and magnetic fields associated with those solar flares constituted the worst known coronal mass ejection from the sun ever to hit the magnetosphere. 

Thus began the Carrington Event, during which the Aurora Borealis and its southern polar opposite, the Aurora Australis, extended toward the equator in latitudes where they had never been seen before, causing people all over the planet to panic that the world was coming to an end.

The part of all the Carrington phenomena that would be most significant to us in the present day was the impact it had on the telegraph network throughout North America and elsewhere. By 1859, two years before the beginning of the U.S. Civil War, sending telegrams was a regular part of business, personal and government activity. As a further indication of its prominence, the first transatlantic telegraph cable was laid in that same year, although it failed three weeks later. Disruption of the telegraph network in September 1859 affected many.

Carrington sketched and annotated sunspots from images cast by his telescope. In this Sept. 1, 1859 illustration, he recorded his first-ever sighting of solar flares atop sunspots. | Wikimedia Commons

Carrington sketched and annotated sunspots from images cast by his telescope. In this Sept. 1, 1859 illustration, he recorded his first-ever sighting of solar flares atop sunspots.
Wikimedia Commons

The full story of the Carrington Event contains dramatic elements worthy of a Hollywood blockbuster movie, starting with the biography of the protagonist, whose focus on the sun reshaped the future course of astronomy in an era when others were mainly concerned with studying the stars to unlock further solutions to celestial navigation. Before the end of his days, there were dramatic episodes with a love triangle, courtroom drama and, in a denouement, an attempted murder-suicide. But most exciting would be the opportunity for CGI special effects portraying the fiery contortions of sunspots, solar flares and coronal mass ejections far more breathtaking than most science fiction.

Perhaps more than anything, a movie would provide the only means to convey the consequences that a coronal mass ejection could bring to our civilization that is now so dedicated to the electrification of everything.

Why this matters today 

It turns out that some of the biggest physical components of the U.S. electrical network constitute its weakest links. High-­voltage transformers, which have always been “long-delivery” items, take longer—and cost more—than ever. In a geomagnetic storm, transformers are vulnerable to induction caused by the results of coronal mass ejections.

Strategic threat analyses in government, academic and expert studies identify a variety of sources and forces to protect against. But none is more strategically or tactically indefensible than geomagnetic storms.

Some studies have concluded that simultaneously disabling a certain combination of just nine high-voltage substation transformers could disrupt the country’s entire electrical infrastructure—and a geomagnetic storm might do just that. The possibility is mind-boggling.

In the worst imaginable outcome, during a recovery period in the aftermath of the trillions of dollars of property damage that would mount up, out of a world population of 8 billion, many millions of people in every strata of the “electrified” world would die from dehydration, starvation or exposure to heat or cold. The approximately 10 million people around the globe who continue to live their daily lives without electricity would be able to maintain their lifestyles.

In a geomagnetic storm, transformers are vulnerable to induction caused by the results of coronal mass ejections.

A tragic ending

Years after he had gained fame as an astronomer, Carrington succumbed to the frailties of an ordinary man. On a street in London in 1868, he suffered from an incurable case of love at first sight when he encountered a beautiful younger woman named Rosa. Thereupon he began his personal campaign to win her hand in marriage, but for quite a while she refused his entreaties.

Rosa was indeed beautiful, but she was illiterate. She explained that she lived with her brother and continued to decline Carrington’s offers of marriage. But after he added the promise of the estate she would someday inherit, she relented, and they were married.

Soon afterward, however, she refused to live with him in his country mansion. After she moved back, the man she had identified as her brother arrived at the door, while Carrington was away, and in a rage stabbed Rosa and then himself. They both survived. He faced criminal charges, a jail sentence and the revelation in a dramatic courtroom scene that he was an ex-convict living under an assumed name.

Carrington had quietly learned this man was not her brother, but rather her lover. To help her overcome the mental trauma that plagued her, a doctor provided Carrington with a drug intended to be taken in small doses to calm her nerves. Sadly, one day he gave her a larger dose, fatally poisoning her. Not long afterward, Carrington himself was found dead in his mansion. The location of his biggest discovery became a memorial to his amateur pursuit that changed the course of astronomy forever.



Some fast astronomy facts

Solar cycle

The sun’s magnetic activity is measured in 11.11-year periods demarcated by sunspot activity. Numbered as far back as 1755, solar cycles have highs and lows. The Carrington Event occurred in solar cycle 10 (1855–1867). We are currently in solar cycle 25 (2019–2030), with an anticipated peak in 2025.


Appearing as dark areas near the surface of the sun, sunspots are the result of magnetic activity that reduces temperature. Richard Carrington used his telescope to project images of sunspots onto a drawing board. 

Solar flares

Eruptions caused by electromagnetic radiation, solar flares are often, but not always, accompanied by coronal mass ejections, solar particle events and other solar phenomena. They vary in frequency in the solar cycle. 


Plasma is one of four fundamental states of matter. It is a combination of charged particles. While we might think of it least, it is the most abundant form of ordinary matter in the universe, making up stars, including the sun.

Coronal mass ejections

Abbreviated as CMEs, they occur when large clouds of magnetized plasma erupt and escape from the sun’s corona. They are often connected to solar flares. They were not known as such in Carrington’s day. It took observations from modern telescopes and satellites to recognize them for what they are in the 1970s.

The magnetosphere

The magnetic field that protects Earth from solar and other radiation, and keeps the solar wind from carrying away the atmosphere. It is largely responsible for making the planet habitable. It is aligned roughly 11 degrees away from the Earth’s axis of rotation, with one pole in northern Canada, the other in Antarctica.

Header image: Getty Images / Veronika Oliinyk

About The Author

MCCOY is Beliveau professor in the Dept. of Building Construction, associate director of the Myers-Lawson School of Construction and director of the Virginia Center for Housing Research at Virginia Tech. Contact him at [email protected].


SARGENT is president of Great Service Forums, provider of management education for service managers. Contact him at [email protected].





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