Planets Screen Saver Description:

Displays color images of different planets as your screen saver or wallpaper.
The screen saver displays the images as a slide show. You can choose the time delay between images, select from 14 different transition effects, stretch the images to fit the screen, display the images sequentially or randomly, and optionally display the images in black and white for an artisitic effect.

You can also choose any of the images as your desktop wallpaper, and can choose how often to cycle the wallpaper (in hours, days or weeks, or never)