The earth, the moon and the sun

Tonight, my Cubs are doing the “Astronomer” badge. I thought it might be rather nice to give them an idea of the local solar system before moving on to the Big and Little dippers – and of course, how they can find the north star, Polaris.

For reference, I thought I would stick a British 2p coin on the wall as the Earth, and work out towards the sun via the moon.

2p coinIt turns out (and I didn’t know this) that:

  • The Earth is about 8,000 miles in diameter
  • The moon is around 2,000 in diameter
  • The Sun is about 850,000 miles in diameter

The long and short of it is this: If I stuck a 2p on the wall, the moon would be 78cms away away (about 2’6″) and the size of a pea. The sun would be 310 meters away, and 2.6 meters in diameter (7 feet or so).

Good, eh?

It was a good night. If you fancy doing this badge with your cubs, let me know. I have some flips you can have. If you are local, I also have an overhead projector which is great for displaying “real” stars on the wall :)