Some animations on this web site use Flash. To see those animations, you must have Flash on your computer and set up to work with your web browser.
- Click here to go to the Flash page on Adobe's web site. You can download the version of Flash that will work on your computer from that page. Follow the directions provided by Adobe.
- If the link above does not work for some reason, click here to go to Adobe's home page, then follow links to their Flash download page.
The animation below uses Flash. If you cannot see two planets circling the Sun in the animation below, you do not have Flash set up properly on your computer and will need to get it from Adobe's web site.