This feature is useful because it allows the removal of background clutter on certain models that you create. As with all RISC OS menus, clicking on a choice with Select closes the menu. If you want to turn some planets on, or others off, you should use Adjust. In this way, the menu remains open. Range fades the tracks so they are darker in the distance.
History fades the track from trailing behind the planet.
This will be useful when demonstrating the software on a TV screen where individual, distant planets are not easily seen from afar. The default is 360 degrees. Contrast and brightness of the tracks can also be set. For the brighter stars, the constellation itself is shown in detail. Unfortunately, the separate image of the constellation cannot be saved.