Solar Wind
Definition
A continuous stream of charged particles flowing outward from the Sun through the solar system.
In plain language
The Sun constantly leaks electrons and protons into space, like a fine spray blowing off a boiling pot. This wind sweeps past Earth day and night at hundreds of miles per second — it is the raw fuel for every aurora.
The science
The solar wind is a magnetized plasma escaping the hot corona, typically 300–800 km/s at 1 AU with densities of 1–10 particles/cm³. It carries the interplanetary magnetic field; its speed, density, and IMF orientation govern energy transfer into the magnetosphere.
Why it matters for aurora viewing
Faster, denser wind with a southward magnetic field means stronger auroras. Live solar wind data is the closest thing to a real-time aurora crystal ball.
See this in action on tonight's data.