Ridley Scott's Prometheus is now available on DVD, Blu-ray and Blu-ray 3D. Among the many special features is Scott's own feature-length audio commentary wherein he provides a brief update about the status of his upcoming Blade Runner sequel.

"I'm going through Blade Runner now," Scott says, likening the process to his work on Prometheus. "You start off with a blank sheet and you start to evolve. Sometimes you walk into this wilderness of mirrors that don't make any sense at all. Then, suddenly, two and two do make four and you think, 'Oh, that's good,' and you put that up there. It's a series of paving stones."

Among the commentary's other insights is Scott's explanation for casting Guy Pearce as a 96-year old man. Because of the way cryogenic sleep is portrayed in the film, Scott imagines a world wherein crew members are provided mental exercises to keep their brains from atrophying. A scene was planned and never shot that would have seen a younger Peter Weyland.

"I had every intention of showing him as a younger man on board the super yacht in the cyber-Mediterranean with a lot of cyber-girls," Scott says. "As if he was going to say, at 96, 'If I'm going to into a cyber-sleep and I can select that sleep, I may as well be in my prime at 42 with some super-girls having a jolly good time and doing it for two and half years.'"

You can purchase Prometheus by clicking here.