: Because nitrogen is harder to "excite" than oxygen, purple lights generally only appear during strong geomagnetic storms when solar particles have enough energy to penetrate deeper into the atmosphere.
The "magic" of a purple aurora is actually a chemical reaction in our atmosphere: 1024x768 purple northern lights wallpaper | Nor...
: Sometimes, purple appears at extremely high altitudes (above 180 miles) when nitrogen ions are struck by sunlight near twilight, a phenomenon known as sunlit aurora . Cultural & Spiritual Meanings : Because nitrogen is harder to "excite" than
: These colors form in the denser parts of the upper atmosphere, below 60 miles, where nitrogen is more abundant than oxygen. below 60 miles