十万个为什么·科学启蒙30篇（2）

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北极光为何在夜空中舞动？

The Northern Lights, or auroras, happen when charged particles from the Sun hit Earth’s atmosphere.
These solar winds travel along Earth’s magnetic field lines toward the North and South Poles.
When particles collide with oxygen and nitrogen gases, they release colorful light energy.
Green auroras come from oxygen at lower altitudes, while red appears higher up.
Purple and blue lights result from nitrogen molecules being excited during intense solar storms.
Auroras look like flowing curtains because magnetic fields guide particle paths in wavy patterns.
Their brightness and shape change with solar activity, which follows an 11-year cycle.
Cameras often capture more color than our eyes see, especially in dark conditions.
People near the Arctic Circle see them most often, but strong storms make them visible farther south.
Studying auroras helps scientists understand space weather and protect satellites and power grids.