The Northern Lights are nature’s most spectacular light show, but the story actually starts 93 million miles away on the Sun.
1. The Solar Wind
Our Sun is a constant nuclear furnace. It doesn’t just sit there; it’s constantly throwing out a stream of charged particles (mostly electrons and protons) known as the Solar Wind. During periods of high activity—like our current Solar Maximum—the Sun also releases massive clouds of gas called Coronal Mass Ejections (CMEs).
2. The Earth’s Shield
Earth is protected by a magnetic “bubble” called the Magnetosphere. When the solar wind hits this bubble, most of it is deflected. However, near the North and South poles, our magnetic field lines curve inward, creating a “funnel” that allows those charged particles to enter our atmosphere.
3. The Collision
As these high-speed particles slam into Earth’s atmosphere, they collide with gas molecules. This process is very similar to how a neon sign works: electricity excites the gas inside the tube, causing it to glow.
The Altitude of Color
The colors we see depend on the type of gas being hit and the altitude where the collision happens:
| Color | Gas | Altitude |
|---|---|---|
| Red | Oxygen | Above 200 km |
| Green | Oxygen | 100 - 200 km |
| Purple/Blue | Nitrogen | Below 100 km |
Because green occurs at the altitude where our atmosphere is most dense with oxygen, it is the color we see most frequently.
Key Takeaway for 2026: We are currently in the peak of Solar Cycle 25. This means the Sun is more active than it has been in over a decade, leading to more frequent and more intense aurora displays even at lower latitudes.