Sigourney Weaver was well into the publicity tour for "Avatar" when something the movie's creator, James Cameron, said threw her for a loop.

"Jim was telling someone about how sci-fi had always gotten a bad rap, and that maybe now that would change," Weaver recalls. "And I thought, 'Science fiction? Really? Is that what this movie is?' Because to me it's just a great story that happens to take place in another time."

The reaction of the star of the Alien franchise is a clue to why two of the 10 movies battling for the best-picture Oscar — Cameron's box-office conquering "Avatar" and Neill Blomkamp's upstart "District 9" — were chosen from the other side of the cinematic tracks.

Although sci-fi boasts a rich populist tradition, the genre typically gets slighted by the Academy of Motion Picture Arts and Sciences. Only three sci-fi movies have ever received best-picture nominations (see sidebar), and none won the Oscar.

Now, 27 years after "E.T." was mugged by "Gandhi," not one but two sci-fi films will vie for the gold on March 7. So what gives?

The cynical story line goes like this: "Avatar" is on the list because the box-office-conscious academy members cannot ignore a movie that already has earned more than the gross domestic product of some small countries (a staggering $2.5 billion globally). And "District 9" made the list because, well, the list got longer.

Ticket sales often lead to Oscar glory — cue Cameron's "Titanic." And the doubling of the number of nominees allows more latitude in recognizing the year's most buzzed/tweeted fare.

But both points sweep over sci-fi's powerful storytelling weapons (metaphor chief among them), ignore what appears to be a changing of the genre guard (from fantasy to sci-fi), ignore special-effects breakthroughs (arresting images now available at unthinkably low costs) and underestimate the tech foundations of today's popular culture.

THE FUTURE IS NOW

"We seem to be witnessing a geek ascendency, whether it's with the ubiquity of toys like iPods or the appreciation of sci-fi entertainment," says John Scalzi, a sci-fi author and creative consultant to the Syfy channel's "Stargate Universe." "It's a great time for the genre, between these movies, TV shows and a channel dedicated to it. Sci-fi lovers should be excited. This success should breed more of the same."

The possibilities of Oscar glory aside, the ultimate prize for the creators of both nominated films may be the satisfaction of launching a new Hollywood era of science fiction, says Vivian Sobchack, author of "Screening Space: The American Science Fiction Film."

"The genre now has in essence been made legit by the academy's imprimatur. This alone will bring about more greenlighting of sci-fi films," she says. "That said, I'd hesitate to call this a resurgence of sci-fi moviemaking. Because really, they've always been here."

True. One of the first movies ever made was 1902's "A Trip to the Moon," French film pioneer Georges Melies' 14-minute fantasy pitting men against a lunar race called Selenites. The genre picked up steam in the '50s and '60s as the Cold War and space race fueled both paranoia and imagination. Sci-fi films deftly used their otherworldly settings to tell often puzzling stories about the human condition, perhaps best exemplified by Stanley Kubrick's 1968 epic, "2001: A Space Odyssey."

Sci-fi offered up as much low-budget schlock as it did visionary genius, even if sometimes years had to go by before the latter could be appreciated. Such was the case for Ridley Scott's "Blade Runner," a noir masterwork revered by sci-fi fans and scholars alike. Interestingly, it bowed the same year, 1982, as Steven Spielberg's "E.T.," showing that the academy much preferred its sci-fi light vs. dark.

Nevertheless, it was "Blade Runner" that inspired today's auteurs.

"Movies like that showed me that sci-fi could be the glaze you add to a story, something to help deflect you from facing a topic head-on," says Blomkamp, the South African director and co-writer of "District 9," a movie that asks: What if humans weren't afraid of alien invaders but instead treated them like so much unwanted garbage?

WHEN ALIENS ARE US

"There are just so many layers of analogies and metaphors that sci-fi lets you play with," Blomkamp says. "I knew I was having a blast doing this movie, but honestly, when I heard about Oscar nominations (for best picture and screenwriting), I thought, 'This is insane, for a gory sci-fi film?' I still can't believe it."

Sci-fi fans take particular pleasure in the "District 9" nomination, says Lucius Shepard, a sci-fi author and film reviewer for Fantasy & Science Fiction magazine.

"That wasn't a pleasant movie to watch. It had no cute elves or sexy babes," he says. "It is much closer to contemporary science-fiction literature, which as a genre has always been respected."

Blomkamp believes that both "Avatar" and "District 9" received mainstream plaudits because of "story, story, story. Ours is a simple human tale, and Jim's is an epic, Kiplingesque narrative. But both offer characters you can relate to."

But there's more than that. These films wrestle with huge and eerily similar themes, says David Cohen, associate editor at Variety. "Both movies have heroes who start out as functionaries with a job to move aliens out of the way, and wind up being turncoats who physically turn alien," he says.

"H.G. Wells' 'War of the Worlds' asked the question 'What if Martians came and treated England the way England treats conquered lands?' Blomkamp's movie asks 'What if aliens came and we just treated them like we often treat each other?'" he says. "'Avatar' is similar, asking, 'What if we treat alien worlds like we treat Earth?' Both films show sci-fi's ability to address contemporary issues in a way that is palatable to mass audiences."

"Avatar" producer Jon Landau says the reason for his and Blomkamp's success is simple: Their movies ask audiences to think. "Our movies offer hard, dystopian visions vs. a lot of fantasy fluff," he says.

Landau adds that the success of "Avatar" should signal to Hollywood studios that "you don't need to be a sequel or based on a TV show or a book to be a hit."

That dart seems aimed at most of the sci-fi and fantasy fare of the past few years. Last year alone offered up such derivative titles as "Terminator: Salvation," "Transformers: Revenge of the Fallen" and that sci-fi staple "Star Trek." Before that, audiences ate up the book-derived series "Lord of the Rings" and "Harry Potter."

"It seems that fantasy is starting to fizzle out a bit," says M. Keith Booker, author of "Alternate Americas: Science Fiction Film and American Culture."

"More filmmakers may discover the incredible flexibility of the sci-fi genre due partly to the current momentum but also to the improvement in computer animation and the drop in costs associated with that work."

Blomkamp's movie is a case in point. "District 9" was derived from his six-minute 2005 film "Alive in Joburg," now screening on YouTube. The director made it on his own dime.

"Alive" impressed "Lord of the Rings" director Peter Jackson, who offered to produce the feature.

"I'd always thought sci-fi was a dirty word, but now I wear that badge proudly," jokes Terri Tatchell, who co-wrote "District 9." "It's a simple story in the end. It's about the oppressor becoming oppressed. Once Neill and I understood that, the rest was easy."

MORE TO COME

"Avatar" and "District 9" use technology to serve the story, which is perhaps why the latest installment of "Star Trek" was neglected for best-picture consideration, says Variety's Cohen.

"Star Trek" creator Gene Roddenberry "was famous for using his TV show to address contemporary American issues that network censors otherwise wouldn't have let him tackle head-on. But the latest movie just went for an epic space adventure," Cohen says.

He is, however, optimistic that the near future will bring more unique storytelling: "Because these movies no longer have to make like $800 million to recoup their production costs, we'll see more eccentric stories told by new voices out of the sci-fi genre."

But will they win Oscars?

Weaver, who has starred in five sci-fi movies in her 40-film career, isn't optimistic.

"With that label, 'sci-fi,' I think it'll be tough," she says. "But of course, to look at these movies with that label is to miss the points they are trying to make. These movies ask us to look at what it means to be human."