#magnetosphere

2 articles

Auroras: Why the Sky Glows at the Poles

How solar-wind particles funneled to the poles by Earth's magnetic field excite oxygen and nitrogen high in the atmosphere, making it emit the green, red, and purple light of the aurora.

10 min read·Aug 22, 2026

Earth & Climate

Earth's Magnetic Field

Why the field is not a buried bar magnet but the churning output of a planet's molten iron heart — how the geodynamo generates it, why the magnetic poles wander and occasionally flip, and how the magnetosphere it throws up keeps the solar wind off the atmosphere.

10 min read·Jul 5, 2026