Solar Winds Solar winds travel at incredible speeds of 400 km/s, carrying charged particles from the Sun to Earth's magnetosphere.

Altitude The aurora occurs 100-300 km above Earth's surface, in the upper atmosphere where oxygen and nitrogen molecules are excited.

Colors Aurora colors depend on which gas molecules are excited: green from oxygen at lower altitudes, red from oxygen higher up, and blue/purple from nitrogen.

Magnetic Field Earth's magnetic field funnels solar particles toward the poles, which is why auroras are most visible in polar regions.

Best Viewing Aurora activity peaks during geomagnetic storms, which occur when the Sun releases particularly strong bursts of solar wind.