How does the Universe expand

Today we have an investigation for little astronomers to demonstrate how our Universe is expanding.

Did you know we are part of a spiral galaxy called the Milky Way? We are located in an arm of the spiral. There are thought to be 100 billion galaxies in the universe. It’s hard to imagine just how vast the universe is.

This is a very simple experiment to demonstrate how the universe is constantly expanding.
What you need:

a ballon balloon


permanent marker


  • Blow up the balloon so its about the size of an orange.
  • Clip it with a balloon clip.
  • Draw dots on the balloon with a permanent marker, these represent the the milky way galaxy.
  • Remove the clip and keep blowing up the balloon.
  • What happens to the dots?

The science bit

The balloon is a model of the universe which is constantly stretching outwards. The balloon shows how the Milky Way is drifting apart.

This activity has been taken from the Space Exploration kit from Science Shop, which we reviewed here. The kit is full of fun and educational investigations, such as making a telescope, making flour craters and showing why we have night and day.

Related posts

Making craters    

How does the universe expand

There are 6 comments

  1. Laura White

    My three year old granddaughter will love this. Finding things to do for preschoolers in science is not that easy. We have just started to study the solar system this will be great.

    Thank you,


  2. Ticia

    Ahhhh, but is it a cycle of expanding and collapsing or does it expand forever? I always thought that was an interesting debate when I was in school. I’m weird that way though.

    Love the visual.

Post Your Thoughts