‘Doctor Who’: The Doctor spans space, time and the world

Matt Smith has traveled the distant past, the far future and the outer reaches of the universe as the iconic British science fiction character the Doctor.

But on Saturday, the boyish English actor will go to a rarefied space typically reserved for moon landings, the Oscars and epic sporting events like the Olympics. As part of a 50th anniversary celebration for the sci-fi show, Smith will be broadcast around the globe in a special TV movie: “Doctor Who: The Day of the Doctor.”

The BBC is taking the golden anniversary celebration to unprecedented levels for a scripted television show. The movie, which also stars David Tennant, Jenna Coleman and Billie Piper, will truly be a global event Saturday as it will air in 75 countries at the same time. In the United States, the special will be shown on BBC America, but it will also be screened in movie theaters as well — also at the same time.

PHOTOS: A first look at ‘Day of the Doctor’

The cult hit about a time-and-space traversing alien Time Lord and his series of human companions originally premiered in England on Nov. 23, 1963 — indeed, its first episode was overshadowed by the JFK assassination. Since then, the series has been recognized by the Guinness World Record as being the “longest-running science fiction TV series.”

Saturday’s “Doctor Who” broadcast, however, will mark the final chapters for Smith’s time in the legendary role. He’ll have one more appearance as the Doctor, a role he’s had since 2009. In the show’s annual Christmas special next month, Smith will “regenerate” and pass the baton to a new Doctor, this one played by “The Thick of It” star Peter Capaldi.

“I’m going to miss it so much,” said Smith in an interview earlier this year.

The 31-year-old actor was a relative unknown before replacing Tennant in the title role. Since 1963, only 11 actors have played the Doctor, with Capaldi being the 12th. It’s the kind of opportunity that can make or break a young career, but Smith has proved himself capable of the task.

PHOTOS: Behind the scenes of movies and TV

His tenure on “Doctor Who” coincided with the arrival of a new show runner, Steven Moffat, and also the show’s newfound popularity in the United States thanks to BBC America and binge viewing on video streaming services like Netflix.

“Smith’s Doctor embodies a more conservative idea of Britishness than either of his [most recent] predecessors,” said Dr. Piers Britton, associate professor of visual and media studies at the University of Redlands currently teaching a course on “Doctor Who.” “He embodies an England where everyone wears tweed jackets and drinks tea. It’s interesting how that’s caught the American imagination.”

Smith, who admitted never watching the series before the role, now signs his checks “Matt Smith — The Doctor.” But it’s not easy being an instantly recognizable icon.

“I try to be as much like the Doctor as possible for little kids,” Smith said. “But sometimes people don’t realize you may have done it five times that day.” He mentions how strange it is when people just walk up and take his picture without even trying to speak to him.

“It’s like you [the actor] don’t even exist,” he said.

Smith’s days as the Doctor may be numbered, but he’s likely going out with a ratings bang. The average global audience for the series is about 77 million, but the combined audience for this 50th anniversary special could hit 100 million people, according to Brad Adgate, analyst at ad firm Horizon Media in New York.

VIDEO: Behind the scenes of ‘Doctor Who’

“It speaks to the popularity of this franchise across borders,” said Adgate, who became a fan of the show when he was introduced to it by his daughter, a sign of the character’s cross-generational appeal. “And because it’s an event, they’ll pick up people who may not know what a TARDIS is, but will want to share in the experience.”

Smith has not elaborated on his reasons for leaving the role behind, other than to say “when it’s time to go, it’s time to go.”

Like every actor who has piloted the TARDIS — the police call box vehicle that propels its occupants through space and time — Smith brought his singular personality to the role.

“I think what he brought back to the role is the absolute nuttiness of the Doctor,” said Moffat, who had originally planned to cast a middle-aged actor before he met Smith. “You put him in a normal situation and you realize he’s an absolute lunatic.”

Despite almost universal disappointment over his departure, Smith believes that change is the secret to the franchise’s longevity.

PHOTOS: Celebrities by The Times

“I’m one-eleventh of this character,” Smith said. A new actor “is like a new coat of paint on the TARDIS. It’s what keeps the show moving forward and how it’s lasted 50 years.”

For Coleman, who joined the series just last year and will continue with Capaldi, watching the show explode in worldwide popularity has been a shock.

“We were in Bristol filming the Christmas special and there were hundreds of people there at the set screaming at you,” Coleman said. “It’s like being in the Beatles.”

And while Capaldi’s turn in the spotlight is just beginning, Smith is already moving on to other ventures. He appears in Ryan Gosling’s directorial debut, “How to Catch a Monster,” and around the time that his final “Doctor Who” Christmas special airs next month he’ll be on stage in London, starring in a musical version of “American Psycho.”

“I’ll take each step as it comes,” Smith said.

[email protected]