Several well-known "M" movies, such as
Mary Poppins (1964),
Monsters, Inc. (2001), and
Mulan (1998). Speaking of
Mary Poppins, did you see the sketch "Crosswalk: The Musical" when James Corden took
The Late Late Show to London last week? He and Ben Kingsley made an interesting Mary and Bert as they performed some of the songs -- in a crosswalk along the Strand in the middle of London.
A couple of other "M" movies are about Mars. In
Mars Needs Moms (2011), a computer-animated film, Milo has to save his mom when she's abducted by Martians. Seth Green was cast as Milo and performed his lines wearing a motion-capture suit, but then the studio decided to use a younger voice. Coincidentally, the boy with that voice was also named Seth--Seth Dusky.
Mission to Mars (2000) focuses on a Mars expedition gone wrong, and the rescue that follows. It stars Tim Robbins, Gary Sinise, Don Cheadle, Connie Nielsen, and Jerry O'Connell.