Jessica Biel voices the alien Neera in Planet 51, out in theatres Friday.

LOS ANGELES -- She outgrew the role years ago, but Jessica Biel hasn't forgotten what it's like to be a teenage wild child.

"When I was 16, I was pushing it on every angle -- with my parents, with the world. I thought I had it going on. I thought I knew everything," says the 27-year-old.

In fact, a decade ago, Biel caused a minor scandal when -- then the 17-year-old star of the wholesome family drama 7th Heaven -- she defiantly stripped in a racy photo shoot for Gear magazine.

The near-nude pictorial garnered Biel plenty of attention -- as well as presaged the current digital age of celebrity in which explicit photos of young squeaky-clean starlets frequently end up (unintentionally, we note cynically) online, just a creepy mouse click away.

In the years since, Biel has outlived both the series and the controversy, compiling a diverse resume -- from the independent dramas The Illusionist and Easy Virtue to the horror remake The Texas Chainsaw Massacre to the comedy I Now Pronounce You Chuck and Larry -- even if she is probably best known for dating Justin Timberlake.

Her latest movie is Planet 51, the digitally animated comedy in which she voices Neera, a green-skinned extraterrestrial teenager who goes from girl-next-door to protest marcher. It opens Friday.

"I had more of a bad attitude, I think, as a 16-year-old. (Neera's) way more of a positive, charitable person than I was. But her confidence and risk-taking, I can relate to," Biel says during today's press conference at L.A.'s historic Griffith Observatory.

"I think I was trying to create that person I was when I was 16: Confident but insecure, pushing the envelope but still being a little kid and thinking she was this strong, independent sexy woman, but still not there yet."

For Biel, however, the appeal of getting to do an animated movie was greater than just any one character.

"Yes, I want to be an alien. Yes, I want to be green. No, I don't want to wear pants. No, I don't want to go through hair and make-up. (Performing the voice) you can just be crazy. You can talk with your hands, you can be really broad, you can take it really small and it's your director who's guiding you along because you're not really reacting to anything."

Even if she had to work on the pitch of her voice to make Neela sound, um, less adult. "They wanted it higher. I was going ... " (pouring on the come-hither huskiness) ...

"'Yeah well.' And they were like, 'We're not trying to make THAT movie,' " she says, laughing.

"I was more like up here, in this pitch, which was hard for me at first, because I want to be ... " (lowering her voice again) ... "down here."

In the movie, Biel's Neera is the dream girl of the hero, Lem (Justin Long a.k.a. the Mac guy), a geeky astronomer whose home world looks an awful like the idyllic but xenophobic America of the 1950s. It's a world disrupted by the arrival of Chuck Baker, a blustery human astronaut voiced by Dwayne Johnson.

"For me it was the first time I had done animation and had to try to bring a character to life with my voice -- just with pitch," says Johnson.

More experienced is Long, whose voiceover credits include Alvin and the Chipmunks and December's followup. ("The Squeakuel's coming out for Oscar season," he says.)

Like Biel, Long found plenty of -- sometimes uncomfortable -- parallels between himself and his alter-ego.

"I was shockingly a bit of a nerd in high school. It was nice to go back to that time before I was jaded and over everything. I had a similar experience, I'm just not as smart. Lem is a lot brighter than me."

Although a kids-aimed comedy -- and clearly a riff of the 1950s B-monster movie genre -- Planet 51 also touches upon the darker, more paranoid side of that period in history as Baker is greeted not with cheer but fear and hostility.

"The idea of this movie is to be open to change," Biel says. "Obviously in our world, a lot is changing, but in this world, a lot is changing as well -- and to be accepting of change, be excited to experience that because it's only then you can grow and learn more about yourself, human or alien."

Although some insecurities, she says, you never entirely outgrow.

"When are you going to work? I don't know. When and can you pay your bills and will it be creatively interesting? I try not to think about it too much."

More Artists