space-weather

The Van Allen belts are zones where Earth's magnetic field traps radiation. How Explorer 1 found them, how they work, and how Apollo and Artemis crossed them.

On September 1, 1859, British astronomer Richard Carrington watched a white-light flare erupt from the sun's surface — the first solar flare ever recorded by a human being. Within 17 hours, a coronal mass ejection carrying several billion tons of magnetized plasma slammed into Earth's magnetosphere at roughly 2,400 km/s (5.4 million mph), triggering the largest geomagnetic storm in recorded history. Telegraph operators received electric shocks from their equipment. Aurora lit the skies over Cuba, Hawaii, and Colombia. If the same event happened today, a 2008 National Academies report estimated the damage at nearly $2 trillion in the United States alone.

In May 2024, auroras appeared over Florida, the Yucatán Peninsula, and Puerto Rico. Northern lights were photographed from latitudes that had not seen them in decades — triggered by the strongest geomagnetic storm since March 1989. The storm was rated G5, the maximum on NOAA's five-point geomagnetic disturbance scale. Solar Cycle 25, which government forecasters had predicted would be 'average,' had quietly become one of the most active solar cycles in a century — and the official models did not see it coming until it was already happening.

What cosmic rays are, how Victor Hess discovered them in 1912, their sources from the Sun to AGN, detection methods, biological effects, and the ultra-high-energy mystery.

How the Sun works: proton-proton fusion in the core, layers from radiative zone to corona, solar wind, sunspots, and the Sun's far future.

NASA's Parker Solar Probe is the first spacecraft to fly inside the Sun's corona — here's what it has found and why it matters.

How auroras form: solar wind, Earth's magnetic field, atmospheric collisions, why they're green or red, and where and when to see them.

A powerful solar storm could knock out global power grids and satellites. Neural networks are our early warning system against the Sun's most destructive outbursts.

Every 11 years or so, the Sun's magnetic activity rises and falls in a cycle that astronomers have tracked since Galileo's era. The solar cycle sets how many sunspots, flares, and coronal mass ejections occur, and it shapes space weather at Earth.

Solar flares, coronal mass ejections, and geomagnetic storms are not science fiction. They have knocked out power grids before, and the next big one could be far worse.