How do auroras form?
Auroras occur when atoms and molecules in the upper atmosphere emit light after interacting with energetic particles. Earth's magnetic field guides particle motion, making auroras most common around polar regions. They are not sunlight reflected from ice.
Energy transfer and colors
Interactions between solar wind and the magnetosphere can store energy whose release drives particles into the atmosphere. Excited oxygen and nitrogen emit at different wavelengths. Color depends on particle energy, atmospheric composition, and altitude. Oxygen commonly contributes green and red emissions, while nitrogen contributes purplish and other tones. No single altitude describes every aurora.
When are auroras visible farther away?
Strong geomagnetic activity can expand auroral regions toward lower latitudes. A solar eruption does not guarantee visible auroras at every location. Clouds, light pollution, darkness, and horizon visibility affect observations. Long-exposure photographs may appear more colorful than the naked-eye view. Auroras are visible signs of energetic processes, not a complete explanation for every communication disruption.