Downey Jr in talks to play cowboy in sci-fi western

Robert Downey Jr. is set to bring a 10-year-old sci-fi movie idea to the big screen after negotiating to star in 'Cowboys & Aliens'.

The 'Iron Man' star is in talks to sign on to the film, about an alien spaceship that lands in the Wild West, according to the Hollywood Reporter.

Brian Grazer and Ron Howard will produce the film, which has been in development for a decade.