The Sun has thrown some extraordinary storms at us — a few that lit the sky to the tropics, one that nearly ended the modern world's lucky streak, and one we can only reconstruct from 19th-century notebooks. Here's the story of each, with the science of why it mattered. Every one can be replayed live in the tracker: watch the coronal mass ejections leave the Sun and sweep out to Earth, with the real solar wind and geomagnetic data behind them.
A barrage of CMEs from giant region AR 3664 drove the first G5 storm in 20 years — aurora to the tropics, and the most-photographed in history.
Read & replay →The most intense storm on record. Telegraphs sparked, aurora reached the equator — and it crossed from Sun to Earth in under a day. A reconstruction.
Read & replay →The most intense flare ever recorded and back-to-back extreme storms — satellites failed, flights diverted, a Swedish grid tripped.
Read & replay →A Carrington-class CME tore across Earth's orbit and missed — hitting a spacecraft that measured the superstorm we were spared.
Read & replay →A textbook full-halo CME with one of the strongest southward magnetic fields ever measured — an extreme storm, aurora to Texas.
Read & replay →The two biggest flares of solar cycle 24 and a severe storm — knocking out HF radio during the Caribbean hurricane season.
Read & replay →A modest CME that punched far above its weight — proof that a CME's magnetic field, not just its speed, makes the storm.
Read & replay →New to space weather? The guide explains CMEs, the Kp index, and how the tracker's arrival estimates work. Want a heads-up when there's a notable storm or a new feature? Sign up below.