Aurora Basics: Auroras, also known as the northern and southern lights, are natural light displays caused by interactions between solar wind particles and Earth's atmosphere.
Green Auroras: The most common color of the auroras is green, produced by atomic oxygen in Earth's atmosphere.
Red Auroras: Red auroras can form both above and below the green bands. At higher altitudes (above 150 miles), red light is emitted by atomic oxygen.
Blue and Purple Auroras: Blue or purple auroras are usually the result of ionized molecular nitrogen or hydrogen and helium at higher altitudes (over 180 miles).
Yellow and Pink Auroras: These colors arise from a mix of red light from molecular nitrogen and green light from atomic oxygen.
Auroras on Other Planets: Auroras have been observed on every planet in the solar system except Mercury, which lacks an atmosphere.
Auroras on Moons: Some moons, such as those of Jupiter, also display auroras.