The story behind thunder

The root cause of the loud bangs and flashes of lightning is a fascinating process.

- By Estelle Trengove

Thunder is the sound that lightning makes. So before I can explain how thunder works, I have to explain how lightning works, and clouds too they all go together.

Not every cloud can make thunder and lightning. Thunderclouds are very tall of course, from the Earth you can't always tell how tall the cloud is because you just see the bottom. But above that, it stretches up tall into the sky.

Clouds are made of tiny water droplets. It's so cold high up in the sky that ice crystals start to form inside the clouds.

Then these crystals move to the top of the cloud and the water droplets stay near the bottom of the cloud. When they move past each other and rub against each other, they make static electricity.

You can make static electricity by rubbing a balloon against your hair and then the static electricity makes your hair stand up. Or, sometimes, when you have socks on and you rub your feet on a carpet, then it makes a tiny shock when you touch somebody else.