What was the Carrington event?

The September 1859 superstorm that followed the first solar flare ever observed. The CME crossed to Earth in about 17.6 hours, aurora reached near-equatorial latitudes, and telegraph systems burned and sparked worldwide.

How strong was the Carrington event compared to modern storms?

Original estimates put it near −1760 nT; modern reassessments place it near −900 nT. Either figure exceeds every storm of the instrumented era — March 1989 reached −589 nT and May 2024 reached −412 nT.

Would a Carrington-class storm happen again?

Yes, eventually — it's a question of recurrence interval, not possibility. Estimates vary widely, but the hazard is taken seriously enough that power-grid and satellite operators plan against it.

How can you simulate a storm from 1859?

From the eyewitness record: 33 timed, geolocated reports of what the sky did. The observatory's simulation is fit to those reports and labeled as a simulation — the record animated, never presented as measurement.

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THE CARRINGTON EVENT · 1859

On September 1, 1859, Richard Carrington watched two patches of white light flare across a sunspot group — the first solar flare ever observed. Seventeen and a half hours later, the sky caught fire worldwide. It is still the benchmark against which every superstorm is measured.

▶ Replay this storm in 3D. A historical simulation anchored to 33 timed eyewitness reports from 1859 — the model's oval is fit to where and when people actually reported the sky burning.

explore it in the observatory →

The first flare ever seen

“…two patches of intensely bright and white light broke out … the brilliancy was fully equal to that of direct sun-light … I saw I was an unprepared witness of a very different affair.” R. C. Carrington, Monthly Notices of the Royal Astronomical Society, 1859² — timed to 11:18 GMT, September 1, 1859

Carrington and, independently, Richard Hodgson had just observed the first solar flare in history. The associated CME crossed to Earth in about 17.6 hours¹ — roughly twice as fast as the 2024 Gannon storm's transit — implying an eruption of extraordinary energy into a solar wind already swept clear by earlier activity.

The storm

Aurora was reported from near-equatorial latitudes; telegraph systems — the era's only electrical infrastructure — sparked, shocked operators, and in places kept transmitting on induced current alone with their batteries disconnected. Early magnetometer-based estimates put the storm's intensity near −1760 nT³; modern reassessments place it near −900⁴ — either way, well beyond anything in the instrumented era.

The simulation

No satellite measured 1859. The observatory renders Carrington as a clearly-labeled historical simulation anchored to 33 timed, geolocated eyewitness reports — the model's oval expansion is fit so that the sky does what the witnesses said it did, when they said it did⁵. Nothing about it is presented as measurement; it's the record, animated.

Could it happen again?

Yes — Carrington-class eruptions are a question of when, not if. A storm of that class today would stress power grids, satellite fleets and navigation systems far beyond the 2003 or 2024 experience; the infrastructure record is on when the sky reaches the ground. When the next one comes, the live view will render it from the same feeds it renders every night.

Frequently asked questions

What was the Carrington event?: The September 1859 superstorm that followed the first solar flare ever observed. The CME crossed to Earth in about 17.6 hours¹, aurora reached near-equatorial latitudes, and telegraph systems burned and sparked worldwide.
How strong was the Carrington event compared to modern storms?: Original estimates put it near −1760 nT; modern reassessments place it near −900 nT⁴. Either figure exceeds every instrumented-era storm — March 1989 reached −589, May 2024 reached −412.
Would a Carrington-class storm happen again?: Yes, eventually — it's a question of recurrence interval, not possibility. Estimates vary widely, but the hazard is taken seriously enough that power-grid and satellite operators plan against it.
How can you simulate a storm from 1859?: From the eyewitness record: 33 timed, geolocated reports of what the sky did. The observatory's simulation is fit to those reports and labeled as a simulation — the record, animated, never presented as measurement.

Sources

Numbered references for the claims above.

Cliver, E. W. & Svalgaard, L. (2004). The 1859 solar–terrestrial disturbance and the current limits of extreme space weather activity. Solar Physics 224, 407–422. doi:10.1007/s11207-005-4980-z
Carrington, R. C. (1859). Description of a singular appearance seen in the Sun on September 1, 1859. Mon. Not. R. Astron. Soc. 20, 13–15. doi:10.1093/mnras/20.1.13
Tsurutani, B. T., Gonzalez, W. D., Lakhina, G. S. & Alex, S. (2003). The extreme magnetic storm of 1–2 September 1859. J. Geophys. Res. 108, 1268. doi:10.1029/2002JA009504
Cliver, E. W. & Dietrich, W. F. (2013). The 1859 space weather event revisited: limits of extreme activity. J. Space Weather Space Clim. 3, A31. doi:10.1051/swsc/2013053
The Observatory’s own reconstruction pipeline and validation gates are documented on data & methods.

More storms: Gannon May 2024 · Halloween 2003 · St Patrick's 2015 · November 2025

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By The Space Weather Observatory · checked against the data & methods record · Updated August 21, 2026

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