Combine All the Images

The idea is simple: Use the "Add" tool to stack all the Jupiter images together to come up with one image that shows the path of each of the moons. The difficult part will be keeping track of your work. You will be using the Hands-On Universe software.  Although you may think of many different ways to do this, try these steps first:

In order to see clearly which of the many dots on your final image was the first in the series,go to the manipulation menu and subtract the first image from the temporary image TWO times. This will make first three moons appear black.

Save this image.