Why does aurora borealis change colors?

The aurora borealis changes colors because different particles from the sun hit the air up high and make it glow in many ways.

Imagine you have a big bag of colored marbles, red, green, blue, purple. Each marble represents a kind of light that appears when the sun's particles bump into the air molecules far above Earth.

When the red marbles fall out, we see red light; when the blue ones fall, we see blue light. It’s like shaking a bag of marbles, sometimes you get mostly red, sometimes mostly green, and that’s why the aurora can be pink, green, or even purple.

The sun sends out particles called charged particles, which are like tiny, fast-moving balls. These balls zoom through space and hit Earth's upper atmosphere, where they bump into oxygen and nitrogen molecules, the stuff that makes up our air.

Depending on which molecules get hit, different colors appear:

• Oxygen usually gives off green or red lights.
• Nitrogen often shows up as blue or purple.

So when these tiny balls crash into the air, they make a show, like a rainbow in the sky!