In this computer animated movie ten-year-old Milo's (voice of Seth Green) mother (Joan Cusack) is kidnapped by Martians and he stows away aboard the craft. On Mars he sees this underground Martian civilization. There, he encounters another human, Gribble, a guy who seems to be in this thirties. He lives in the civilization's dumping grounds, where all the Martian males seem to live. You see, the women are the "logical" ones who run the city while the males are more "touchy feely", so don't fit into the society. Martian children simply pop out of the dirt every few years but since they don't have mothers, they are cared for by robot nannies. This is the reason they need Milo's mother-- they are going to transfer her "motherness" into programming these robot nannies. But this will kill her. He finds this all out from Gribble, as Gribble had been a stowaway as well all those years ago. There's also Ki, a young martian woman who rebels against her rigid society and ends up helping the two of them.
Yes, this movie is for kids but it's as entertaining as HOW TO TRAIN YOUR DRAGON or SHREK. Recommended.