Why? New York magazine's Vulture blog speculates that Disney is avoiding the word "Mars" after the disastrous flop that was "Mars Needs Moms" this spring.
The movie is based on Edgar Rice Burroughs' pulp novels, one of which was titled "John Carter of Mars." It's the live-action directing debut of Andrew Stanton, who directed Pixar's "Wall-E" and "Finding Nemo." The cast includes Taylor Kitsch as John Carter, Lynn Collins as the princess Dejah Thoris, and Samantha Morton, Willem Dafoe, Bryan Cranston and Thomas Haden Church. The exterior scenes were shot in southern Utah's red rocks last summer.
New York magazine jokes that the new title may cause some confusion for fans of "ER," because John Carter was the name of Noah Wyle's character.