Purple northern lights, while a favorite for high-definition wallpapers, are a rare and scientific marvel caused by the interaction of solar particles with at specific altitudes. These colors typically appear during periods of intense solar activity and are often visible at the lower edges of an auroral display, usually at altitudes of 60 miles (100 km) or less . The Science Behind the Purple Glow
Aurora colors: What causes them and why do they vary? - Space 1024x768 purple northern lights wallpaper | Nor...
The "magic" of a purple aurora is actually a chemical reaction in our atmosphere: Purple northern lights, while a favorite for high-definition
: These colors form in the denser parts of the upper atmosphere, below 60 miles, where nitrogen is more abundant than oxygen. - Space The "magic" of a purple aurora
: Unlike the common green aurora caused by oxygen, purple and blue hues are produced by ionized nitrogen .
: 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.