What are auroral substorms?

Auroral substorms are big bursts of light in the sky that happen when energy from the Sun shakes things up high above Earth.

Imagine you're playing with a slinky. When you pull it tight and let go, it gives a quick, wiggly stretch down the stairs, that’s like how auroral substorms work, but way higher up. The Sun sends out a stream of charged particles, like tiny, fast-moving rocks, which travel through space to Earth's magnetic field. Sometimes, these particles get stuck in a kind of traffic jam near Earth’s poles.

Then, boom!, something happens that releases all that energy at once. It’s like when you suddenly let go of the slinky after holding it tight for a while. This sudden release lights up the sky with colorful flashes and waves, that's an auroral substorm!

What makes them happen?

Think of Earth's magnetic field like a big, invisible shield. Sometimes, the charged particles from the Sun push against this shield. When they do, it creates a kind of pressure. Eventually, the shield lets go with a big splat, and all that stored energy rushes down to the atmosphere, lighting up the sky in green, purple, or red.

It’s like when you stretch a rubber band until it feels tight, then let it snap back, only way bigger and way higher up!

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Examples

  1. A sudden flash of green lights in the night sky caused by a solar storm
  2. A child sees colorful lights dancing across the northern sky
  3. The sky turns bright purple and green during a cold winter night

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