How Do Auroras Form in Earth’s Atmosphere?

Imagine Earth as a planet with a shield made of magnetism. When the sun sends out a stream of tiny, fast-moving bits called charged particles, they travel through space and hit this shield. Some of them slip through and race down into Earth’s atmosphere like sparks from fireworks. These bits bump into air molecules, making them glow, and that glowing is what we see as auroras (like the northern lights)!