Five months after the Gannon superstorm, the Sun did it again: another Earth-directed CME, another severe storm, another night of aurora photographed from latitudes that usually never see it. The observatory reconstructs it through the same measured pipeline.
On October 8–9, 2024, active region 13848 launched a fast, Earth-directed CME. It arrived on October 10 and drove a severe (G4) geomagnetic storm2 — at the time, one of the strongest storms of Solar Cycle 25 after May's Gannon event. Aurora was again reported and photographed across the mid-latitude United States and Europe, with the southern oval active over New Zealand and southern Australia.
October's storm mattered for a second reason: it was the rematch. May's superstorm had caught millions of first-time observers by surprise; in October, they knew what to look for. The photographs came in sharper, better-timed, and better-located.
The observatory's October scene is fit from the same measured sources as Gannon — satellite ultraviolet imagery, particle precipitation and magnetic-field data, both hemispheres3. Compare the two storms back-to-back in the replay: October is the textbook severe storm; Gannon is what the extreme class looks like.
Active region 13848 had been crackling for days before it committed. On October 8–9, 2024 it produced a fast, Earth-directed coronal mass ejection, and NOAA's Space Weather Prediction Center posted a G4 watch — a rare move, made with a day's notice, that put the aurora community on alert across two continents.
The CME arrived at the L1 monitors on October 10 and the magnetosphere responded within the hour. What followed was a textbook severe storm: a sharp sudden commencement, a deep main phase driven by hours of strongly southward interplanetary magnetic field, and a long recovery through October 11–12. The auroral oval pushed far equatorward of its quiet-time home on both nights, with the first night the stronger of the two.
October's storm produced something May's could not: a prepared audience. The Gannon superstorm five months earlier had caught millions of first-time observers by surprise — most learned the aurora was overhead from someone else's photo the next morning. In October, they knew the drill. Alerts were set, camera settings were saved, dark sites were scouted in advance. The photographic record that came back was sharper, better-timed and far better located, and that matters to this observatory directly: located, timestamped photographs are calibration instruments here, the same class of evidence that anchors the Gannon reconstruction's oval boundary.
The two storms also make a natural teaching pair. October was a severe (G4) storm — a class that arrives a few times per solar cycle and rewards anyone within reach of a dark northern horizon in the northern United States or central Europe. Gannon was the extreme class, the kind that puts overhead color above Texas. Replaying them back to back in the 3D observatory is the clearest way to feel the difference one storm class makes: how much farther equatorward the oval reaches, how much brighter the band burns, how the substorm rhythm changes.
The October scene is fit from the same measured pipeline as Gannon: far-ultraviolet auroral imaging from the DMSP/SSUSI instruments, particle precipitation from the POES and MetOp environmental satellites, and field-aligned current patterns from the AMPERE constellation — both hemispheres, through both storm nights. Between satellite passes the oval boundary evolves along a relation fitted to the measured record rather than an artist's guess, and the ring fits that place the band were re-anchored against the satellites' own imaged boundaries. Where the southern hemisphere's source imagery was compromised — night one over Australia fell in a satellite data gap, and a waxing gibbous moon washed out the optical record elsewhere — the reconstruction says so instead of inventing coverage. That honesty rule is the whole method: everything rendered is measured, or labeled as a model.
Numbered references for the claims above.
More storms: Gannon May 2024 · November 2025 · Halloween 2003 · Carrington 1859
By The Space Weather Observatory · checked against the data & methods record · Updated August 21, 2026
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