Dakota Fanning took the small role of Jane in order to prepare for her role as Cherie Currie in The Runaways (2010) biopic, with her co-star Kristen Stewart. She later said that the role helped her to establish the relationship between the two in real-life and characters Currie and Joan Jett, which Fanning and Stewart play respectively.
During an argument between Bella and Edward in the truck outside her house, the Edward that got out of the truck was actually a double dressed like Robert Pattinson in the seat. Pattinson was actually positioned next to the camera but out of sight. After the double moved out, Pattinson stepped in front the camera. Chris Weitz pointed out that this was trick deliberately done to simulate how Edward moved in and out of the truck in an inhuman manner.
After months of speculation and rumors, director Chris Weitz and the novel's author, Stephenie Meyer, confirmed on her official website that Taylor Lautner would be reprising his role as Jacob Black. It was doubted as the filmmakers feared he would not be able to become fit enough in time. However, he was given the go-ahead after gaining 26 pounds of muscle.
Michael Sheen, who portrays Aro, titular head of the Vampire species, also portrayed Lucian, leader of all Lycans (werewolves) in the popular Underworld series of films, in which Vampires battled werewolves.
When Michael Sheen was cast as Aro, he had no clue of who the character is nor what are his characteristics. He learned as much as he could including the character's back story from his daughter Lily Mo Sheen who is a fan of the series.
A vampire's diet is revealed by the color of the eyes - the Cullens feast only on animal blood and therefore have topaz eyes, whereas the Nomads and the Volturi have red eyes indicating they feast upon human blood.
When Carlisle is cleaning out Bella's wound after her disastrous eighteenth birthday party, he drops a match into the bowl with the glass, blood gauze, etc. If you look closely, you can see that it resembles the cover of the novel 'New Moon'. This is similar to what Melissa Rosenberg did in Twilight (2008), when Edward caught the apple that Bella dropped in the cafeteria.
Throughout Twilight (2008), Kristen Stewart wears brown contact lenses in order to match Bella's eyes. The same is true of The Twilight Saga: New Moon (2009), except for one scene (the Jacob/Bella "break-up" scene outside of Jacob's house). In this scene, Stewart did not wear lenses. Instead, her brown eyes are actually CG applied during post-production. This was because the large amounts of rain kept affecting her lenses.
Contrary to scheduling conflict claims, Catherine Hardwicke turned down directing this film because the release date set by Summit (exactly one year after the first film's release) would not allow her to have enough time to work on the script. With Hardwicke out, the studio scrambled in looking for a replacement director until producer Wyck Godfrey had to turn to his friend Chris Weitz who eventually agreed to do the film.
At the entrance of Emily's house, a Quileute drum is visible there. According to the production designer, David Brisbin, this was done as an appreciation to a young Quileute girl who gave Brisbin the drum that she made (as a custom) during meeting with the La Push Quileute executive council - Brisbin was with the design team meeting them at that time while preparing to design Sam and Emily's house.
The town of Montepulciano was chosen because of its uncanny resemblance to the Italian town described in Stephenie Meyer's novel. The only difference was that its main square lacked a fountain which production designer David Brisbin duly had built from wood.
Director Chris Weitz said this was an easier process than his other film The Golden Compass (2007) as he found "a lot less interference from Summit [Entertainment] and a lot more understanding of the books than New Line had of The Golden Compass" - which Chris said ended up being "completely re-cut" by the studio. He thinks that Summit Entertainment "understands the importance of the [Twilight] books - members of which who have read the books and appreciate them - not just see them as engines of possible profit."
In the book, Bella (Kristen Stewart) works part-time at a sporting goods store with Mike Newton (Michael Welch), which his family owns. In the film saga, Bella never has a job and her friendship with Mike becomes very distant.
Peter Lambert edited a portion of the film during his daily commute. This may be the first major motion picture in which the biggest portion of the first assembly of the film was edited in the backseat of a car.
In the music notes, Alexandre Desplat said that the romanticism nature of the music score that Chris Weitz and him envisioned was referenced to the works Desplat's mentor, Maurice Jarre. The music note credits has a special dedication line to Jarre.
In the scene where Bella, Mike and Jacob are standing outside the movie theatre about to see 'Face Punch' behind Kristen Stewart in the window of a store across the street you can see a poster for the 1958 film 'The Screaming Skull'.
This film is the first sequel Chris Weitz has directed. He was signed on to direct a sequel to his previous film, The Golden Compass (2007); like this film, the sequel was scheduled to be released in late 2009.
When Bella is first brought down to meet Aro and the rest of the Volturi, Aro grabs Edwards hand and says "La tua cantante" which is the Italian expression for a human whose blood particularly appeals to a certain vampire in an extreme sense. In English, it means "your singer", but is usually shortened to "singer" whenever someone refers to her/him.
The trivia items below may give away important plot points.
The scene where a near-death Bella is sinking into the depths was achieved by putting weights in the actress's pockets and letting her sink in a swimming pool. Kristen Stewart was apprehensive about this, so director Chris Weitz demonstrated, to show that there was nothing to be afraid of. As soon as he hit the bottom, he panicked, pulled the weights out of his pockets, and resurfaced, saying "We can't do that to Kristen!" They filmed her from the side and moved the camera backwards to achieve the effect of sinking.
The scene where Bella (Kristen Stewart) accepts the motorcycle ride in Port Angeles was not in the book. In the book, Bella leaves with Jessica (Anna Kendrick) after seeing the vision of Edward. In the film, Bella leaves Jessica in front of the alley and accepts a ride on the man's motorcycle in an attempt to see Edward again.