When a loving suburban mom is seized by an alien snatch squad and whisked off to Mars her nine-year-old son hitches a lift aboard the rocket. However, after hooking up with a renegade American astronaut who's made his home on the Red Planet, he discovers that his mum's life is in danger and he's only got hours to save her. Using Robert Zemeckis's constantly improving motion capture technique, this is a captivating and visually impressive kids' outing with a standout and largely improvised vocal turn from Dan Fogler as stranded spaceman Gribble.
It seems that Martian mums have got rubbish parenting skills so the cosset-challenged aliens need to head to Earth and grab a good old American mom every now and then.
The most recent reluctant purveyor of nannying skills is the mom of nine-year-old Milo (voiced by Seth Green), a typical sprog who won't eat his greens or take out the trash.
However, he has responsibility foisted on him when he hitches a ride on the rocket transporting mom (Joan Cusack) to the Red Planet and certain death after her parenting memory banks are surgically removed.
Escaping the clutches of the Martians, he finds himself in the lair of rebel human astronaut Gribble (Folger), a gadget-obsessed loner who promises to help him get his mom back.
The work of Britain's movie-making marriage of Simon (great-grandson of H.G.) and Wendy Wells, this visually stunning animation is bolstered by a sharp script, particularly the all-too-real interplay between mom and Milo.
Folger's largely improvised dialogue is inspired and includes the rather good joke that he was part of Ronald Reagan's astronaut recruitment programme put together to save the Red Planet from Communism.
Mars - a fascist state run by the authoritarian Supervisor (Sterling), a grizzled ET - is a stunning creation, a vast steel and glass palace patrolled by female stormtroopers.
Producer Zemeckis's motion capture technique has come a long way since the rather creepy human renditions of The Polar Express with the current crop barely discernible from the real thing.
It's a solid, well-made family movie proving - as if it really needed to be said - that mum is the word.