Where does Thunder come from?
  • Thunder is the sound of air exploding as lightening heats it up. The air rushing out sets up a sound wave of vibrating air.
  • A strike of lightening immediately heats up the air to between 15,000 and 60,000 degrees Fahrenheit, hotter than the Suns surface.
  • When the air is heated so quickly it expands violently and then contracts which causes an explosion of air that creates the sound of thunder.
  • Lightening and Thunder happen at exactly the same time but because light travels faster than the speed of sound, you always see the lightening first then hear the thunder a few seconds later. The longer the gap between the lightening and thunder the further away the thunderstorm is.
  Did You Know?
  • There are over 8 million lightening strikes a day around the world. That means there are 100 lightening strikes per second each day.
  • A thundercloud is called a Cumulonimbus cloud.
  • In countries like America and Australia they get a lot of ‘fork’ lightening which looks like a zigzag line of lightening in the sky. In New Zealand we seem to get more ‘sheet’ lightening which is like a bright flash that lights up the sky.
Make thunder

Blow up a balloon or a paper bag and pop it.
What happened? You made thunder!
When you force air into the balloon or bag, the air becomes compressed. When you pop the balloon or bag, the air expands rapidly as it escapes. This creates the sound waves that reach your ears as a popping sound or thunder!
Count the seconds

Next time you see lightening, count the seconds until you hear the thunder. Light travels faster than sound and the sound of thunder takes about three seconds to travel one kilometre. If you count to three just before you hear the thunder, the lightening is about one kilometre away. If the lightning and the thunder happen at the same time then the lightening is very, very close!
Why did the lightening show its bottom?
It couldn’t find its thunderpants.

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