SpaceWeatherTracker Academy
Aurora Encyclopedia
Everything about the Northern Lights in one place — the science, the forecasts, the photography, and the places to stand when the sky turns green.
What are the Northern Lights?
The Northern Lights — the aurora borealis — are the visible glow left behind when charged particles from the Sun slam into oxygen and nitrogen in Earth's upper atmosphere. Earth's magnetic field acts as a funnel, steering those particles down over the polar regions, which is why the aurora forms in the ring-shaped "auroral oval" around each magnetic pole.
This encyclopedia is the reference layer behind our live aurora forecast. If a number, term, or concept shows up on the dashboard and you want to know what it actually means, it's explained here.
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Aurora basics: quick answers
Auroras happen when charged particles from the Sun, carried by the solar wind, are funneled along Earth's magnetic field lines and collide with oxygen and nitrogen high in the atmosphere. Those collisions release light — the shimmering curtains we call the aurora.