What Causes Auroras?
The Big Idea
Witness the breathtaking light show of the Northern and Southern Lights. Discover how the Sun’s violent solar wind crashes into Earth’s magnetic shield, creating a glowing neon dance of colors in the night sky.
Key Vocabulary & Concepts
Hands-On Observation Checklist
Teacher & Parent Discussion Starters
- Why is understanding what causes auroras? important in everyday real life?
- What variable or factor had the biggest impact when testing the simulation?
- How does this concept connect to another science topic you have learned about?
What Causes Auroras?
A Cosmic Laser Show
If you ever travel to the extreme far north (or far south), you might look up into the freezing night sky and witness massive ribbons of neon green, pink, and purple light dancing across the stars. This stunning, silent light show is called the Aurora Borealis (or Northern Lights). It looks like pure magic, but it’s actually a violent, invisible war happening at the very edge of space!
The Solar Assault
The story of the Aurora actually starts 93 million miles away at the Sun. Our massive star is constantly violently boiling, and occasionally it burps out a massive cloud of super-energized particles called the "solar wind." These particles absolutely rip through the solar system at a million miles per hour.
When this deadly, radioactive solar wind slams into Earth, we don’t feel a thing. That’s because our planet has an invisible, protective superhero shield: the magnetic field. This magnetic bubble deflects most of the dangerous particles around us. But at the North and South Poles, the magnetic field lines actually bend inward like a funnel.
Some of those hyper-fast solar particles become trapped in this funnel and are forced downward, crashing straight into our upper atmosphere. When the solar particles strike oxygen and nitrogen gases in the sky, they violently transfer their energy, causing the gas molecules to glow like giant neon signs. Oxygen glows green and red, while nitrogen glows blue and purple. The Aurora is literally the glowing fallout of our planet defending itself against the Sun!