What Causes the Color of Auroras in the Sky?

The color of auroras is caused by tiny particles from space colliding with gases in Earth's atmosphere.

Imagine you're playing a game of tag with your friends outside. You run really fast and bump into someone, that’s like what happens when charged particles from the sun, called solar winds, zoom through space and hit Earth's magnetic field. This makes them go on a wild ride down to our atmosphere.

When these speedy particles crash into gases in the sky, like oxygen or nitrogen, they make those gas atoms light up, just like when you turn on a flashlight in a dark room.

• If oxygen is hit, it glows green or red, depending on how high it is.
• If nitrogen is hit, it usually shines blue or purple.

It’s kind of like when you shake a bottle of soda, the more you shake it, the more bubbles pop up. The same way, the more collisions happen in the sky, the brighter and more colorful the auroras get!