This is the best collection ever of Mars Digital Pictures from over the century of study and exploration, complete with educational captions reviewed by NASA/JPL scientist. Included are images from NASA, JPL, USGS Planetary, and Hubble Telescope. Includes 150+ Pictures with a paragraph on each image you can actually use. Install pre-made screen saver or create your own custom desktop screen. Bonus Video Clips of Mars. Also an internet resource guide of Mars related web sites. This will work with PC: Windows 98/2000/XP or later and MAC: OS 8/9/X or later.