Stargate: Extinction , previously known as Project Twilight, was the production name for the first movie based on Stargate: Atlantis, which would have followed the series' fifth season. Stargate: Extinction was to air on Syfy, and would have been followed by more adventures from the lost city of the Ancients if it would have been a success.
The film would have played into the established mythology of Stargate: Atlantis, but the story wouldn't have the burden of tying up loose story threads from the television series. It would have been more like Continuum than Ark of Truth in that it would continue the story of Atlantis in a one-off offering. While the adventure would have been stand-alone, the character moments would certainly draw on past experiences and future potential. While there was certainly potential for crossovers by SG-1 actors, executive producer Joseph Mallozzi hoped that the two series of movies would remain distinct.
According to Joseph Mallozzi, "It's not so much an arc driven movie as an adventure that incorporates a lot of the back story elements that we've presented up to this point including the city itself, our characters, and some recurring characters. The movie will be better than season five." Todd was going to be in the movie. 
- Amanda Tapping confirmed that she agreed to appear in the Atlantis movie.
- The Wormhole drive was confirmed to be used in this movie.
- According to Joseph Mallozzi, "Weir's story ended in Ghost in the Machine. The character will not be appearing in the movie."
- Joseph Mallozzi stated: "I can't predict whether an ongoing series of Atlantis-based movies will prove successful." "However, if the performance of the two SG-1 movies is anything to go by, the audience is out there."
- Joseph Mallozzi stated: "While I like the idea of some crossover, I think SG-1 movies should be SG-1 movies and Atlantis movies Atlantis movies," he said. "Two movies of each a year would be a true best case scenario." No comment was made on the idea of Stargate: Universe movies.
- Joseph Mallozzi stated: "The number of Stargate movies produced each year will depend in part on scheduling." "I think that we could produce as many as three Stargate (either SG-1 or Atlantis) movies a year," he said. "Four is a long-shot, but very possible."
- Joseph Mallozzi confirmed on the June 13th 2010 blog entry that the information found on the film's IMDB page, including writers and a possible release date, is "wishful thinking."
- Joseph Mallozzi stated: "I'm sorry to say but the cancellation [of Stargate Universe] puts the brakes on whatever progress the SGA movie had made in the past month, shelving it indefinitely. ... Contrary to what some may think, the cancellation of SGU is very bad news for those looking forward to an Atlantis movie."
- Joseph Mallozzi stated: "For what it's worth, it involved a return mission to Pegasus, the tragic end of one relationship, the beginning of another, and a surprising progression in the alliance between one man and one Wraith."
- A further comment by Mallozzi in his blog states that it would have been revealed that the moonbase mentioned on SG-1 was Atlantis which had been relocated there.
Potential plot elements
- Atlantis has been moved from Earth to Earth's moon.
- The gate has been offline since its return to Earth. Under pressure from the IOA, the decision is made to bring it back online and establish Atlantis as a permanent lunar base.
- Gateworld.net retrieved February 11, 2011
- Gateworld.net retrieved February 7, 2009
- Gateworld.net retrieved October 2, 2008
- Gateworld.net retrieved August 24, 2008