Fun Science 'Save the Moon' part 1

I wrote this experiment 'Save the Moon' for the 2007 EX.I.T.E science summer camp at the IBM Ottawa labs. Try it on your computer with the instructions below.

1. Run the program SpaceSimulation3.java. If it is your first time, learn how to run Java programs. We are going to modify this program to save the Moon...

What happens?

Moon falls onto the Earth! Not a good thing...

2. Search line 80 shown below.

80 | planet2.vy = 400;

Replace the value 400 by any value between 0 and 3000. You are setting the initial speed of the Moon - in meters per second.

3. Run the program again. You have succeeded when the Moon does a nice orbit relatively circular around the Earth. What is the value used then?

We will give the answer and a method to calculate this value in a second part...

The beautiful photo of the Moon above comes from John French at the Michigan State University.