Cream of the Milky Way
This is how CD-Roms about space ought to start - stirring music, a picture of the space shuttle ready for take-off - and my screensaver starting up and spoiling everything.

The opening sequence is impressive, taking the shuttle up from Earth to a huge orbiting craft - the Solar System Explorer of the title. Of its several rooms, I got on best in the library. I sampled its files on Mars, and got a combination of moving pictures and voice-over which produced a highly informative piece. Graphics are impressive, pictures are detailed, and the whole package is truly interactive.

I would quibble a little with the segment about life on Mars. The commentator noted (correctly) that the Viking lander had found no sign of life. The craft had cameras as well as scientific equipment and never picked up signs of movement that would signify life. But the commentator concluded by saying that a rapidly moving creature would not have shown up on the scanners. This is slightly misleading; if there is life on Mars, it is going to be microscopic like a bacterium, not large but so rapidly moving that it does not register.

I suspect my PC is a little too elderly to do this CD-Rom justice. I have a 33MHz 486-processor (state of the art just a short while ago) and it was clearly labouring when I tried to get the Solar System Explorer to leave Earth-orbit and fly me to Saturn via Jupiter. People with Pentium processors will, I imagine, fare rather better. Anyone thinking of this CD-Rom as a Christmas present would do well first to inquire - discreetly, of course, about the speed and power of the machine it is to be run on.