We learned about cloud to cloud and intra-cloud lightning.
The other type of lightning that we all know about is called Cloud to Ground lightning, sometimes just called CG lightning.
Electric charges build up in clouds, usually between tiny ice crystals and tiny water droplets that smash into each other.
When this happens to a whole bunch of them at once there is a lot of electricity that needs to go somewhere, so it zaps all the way down to the ground.
(from: wikipedia - lightning)
Kid Facts - Blast from the past: Iron
