What do the colors of the northern lights mean? NASA shares stunning photos of aurora from space

What causes these beautiful displays?

NASA has released some beautiful images of the aurora borealis, also known as the northern lights, captured from space. The pictures show the glowing, colorful lights against the curvature of the Earth, from about 250 miles up.

LOS ANGELES, CA (California Network) -- The Aurora are caused by energetic particles spewed by the Sun which strikes molecules of gas in the Earth's upper atmosphere. When they hit, the solar particle energizes the gas, causing it to glow. The colors of the glow depend on what gas it is.

Above 120 miles, oxygen causes a red aurora; nitrogen causes blue or green to be seen, and below 60 miles, the nitrogen glows purple. Green is the most common color.

The colors depend on altitude and gas and have no meanings, but many people still think they have supernatural significance. Others say that a visible aurora at middle latitudes is a bad omen.

Aurora has also been observed on other planets within our Solar System.

It is difficult for most people to see the Aurora. You need to live as far north as possible and need dark skies. Occasionally, about every ten years or so, a display becomes visible at middle latitudes. As such, seeing one is a matter of luck and being in the right place at the right time.

The closer you are to the poles, the easier it is to see the aurora.