A nice niche for Connelly

Even though a dirty twilight barely seeps through the windows, the lights in the suite at Claridge's Hotel in London are dimmed unusually low, leaving Jennifer Connelly encased in crepuscular splendour.

With her jet-black hair parted almost in the centre, black cardigan and pale skin, she looks oddly like a young Morticia Addams.

This kind of gothic remoteness might be expected if you have starred in Hollywood films for three-quarters of your life. Connelly, 37, has, but this is a strange look for her because there is every indication that she is interesting and decidedly down-to-earth beyond the trappings of her day job.

Her latest role is neither chilly nor earthbound. In a reworking of the 1951 science-fiction classic The Day the Earth Stood Still, she plays a doctor, Helen Benson, an astrobiologist whose love and open-mindedness cause a mighty alien to reconsider his plan to terminate the mess that is mankind. I must have sounded surprised when I tell Connelly I liked the film. "I really liked it too," she says tartly.

With its small American family pitted against a giant robot, the film has all the ingredients of a naff blockbuster and yet is somehow great fun. Best of all is warm, wooden Keanu Reeves, who is perfect as Klaatu, the alien in a human form.

The blockbuster nature of this and her comic role in next year's adaptation of the bestselling dating book He's Just Not That Into You is something of a departure for Connelly. The little girl with the big beetly eyebrows who gallivanted around with the exceedingly tight-trousered Goblin King David Bowie in Labyrinth finally shook off a dodgy series of teen films in 2000 when she played a heroin addict in Requiem for a Dream. Since this acclaimed performance, she has found a nice niche in intelligent and often left-of-centre films, from House of Sand and Fog to her Oscar-winning turn as Alicia Nash, the wife of John Nash, Russell Crowe's schizophrenic mathematician, in A Beautiful Mind.

Connelly clearly takes an earnest intensity into work every day and set about researching her role in The Day the Earth Stood Still with some devotion. She spoke to astrobiologists at Princeton and spent evenings with a big pile of esoteric books, such as Gino Segre's Faust in Copenhagen (although she admits she didn't finish them all). She wanted to explore questions such as 'Does the universe care? Is it a benevolent universe? Is it a neutral universe?' she says. "So I wanted to be reading about other scientists' thoughts."

Did she enjoy working with Reeves? She pauses for a long moment and gives a far more heartfelt answer than the usual actor gushing about co-stars. "I found him to be incredibly passionate about the film and very protective of the story. He was very concerned with telling the story well and serving the story, which I thought was very generous," she says. "I found him to be incredibly diligent and never really found him in repose. I found him always to be working, striving, thinking, asking questions, and I found him to be very kind to everyone in every job description, but not as a game, not as an advertisement for himself and not as a marketing ploy. I found him to be genuinely compassionate. Yeah, I really like him."

The sci-fi classic has been given a contemporary interpretation by homing in on our anxieties about climate change and the environment. Klaatu's mission is to save the planet and all its species by eradicating the humans who are doing so much to destroy it. The film is also very much from an era when Hollywood's liberals have been in open revolt against George Bush and gives an exceedingly unflattering portrait of the US government's shoot-first-and-ask-questions-later approach to the alien 'invasion'.

"One feels echoes perhaps about a general feeling about an administration," says Connelly warily. Things have changed with Obama though, I say brightly, and she perks up. "I'm really excited about it," positively beaming through the gloom. "It was really uplifting - the turnout, the passion, the extent to which people back in the States seemed to care and become engaged." Did you vote for Obama? "Er, yeauuuh," she laughs, as if that was the most idiotic question ever. (It was.) Unfortunately, she was working in Britain, on a film about the life of Charles Darwin, during the election.

"I wanted to be home so badly. I got to work on November 4 and I was like, woo-hoo! Election day!" However, she sighs, none of the Brits on set were talking about it all. They included her husband, Paul Bettany, who she met on A Beautiful Mind. Both have always said their romance began later, after their respective relationships were over. They married within a year and now live in New York with their son, Stellan, and Kai, Connolly's child from an earlier relationship.

In the upcoming film Creation, Bettany plays Darwin and Connelly plays his wife, Emma. How did she find working opposite her husband? Acting together in A Beautiful Mind "didn't really count because . . . I couldn't really pay him any attention," she says, but it was "so fantastic" working with him on Creation. "I loved it. I loved it so much. I wish I could make more movies with him. I'd be happy to make every movie with him. I had such a nice time. He's really good at what he does; I have someone who's equally invested in the movie so I can't bore him to death, because I always talk to him about whatever I'm doing anyway."

Creation tells the story of Darwin's relationship with Annie, one of his 10 children ("Unbelievable," says Connelly. "She gave birth to the last child at 48"), and the struggle between Emma's religiosity and Charles's loss of faith. Is she religious? Connelly is so silent that I tell her she looks as if I have asked a really terrible question.

"I wasn't brought up with any religion at all," she says flatly. Did she explore it later? "At school and in my early 20s I read every religious text I could get my hands on - Buddhist scriptures, Hindu texts, the Qur'an and the Bible. I wanted to feel like something made sense to me, that there was something sacred I could feel aligned with. Then I had Kai and thought this is something that is really concrete and it's sort of a practice in itself - trying to raise him well. It comes with its own set of moral imperatives and it keeps me thinking about the right things and it feels, in a very profound way, a home, which is what I was looking for."

It is a really sweet, interesting answer, so I'm puzzled that she seemed so taken aback by the question. Anyway. As a child star herself, beginning, aged nine, in Roald Dahl's Tales of the Unexpected, would Connelly approve of her sons taking up acting? "I don't really have a vested interest in what they do career-wise, so long as it's neither destructive to their bodies nor illegal. And hopefully not destructive to other people's bodies either," she says sensibly. Kai currently wants to be an architect.

Stellan, five, who is named after the Swedish actor, Stellan Skarsgard, who Bettany met on the set of Dogville, "wants to be an actor when he grows up, which I can't believe. To me, he's so musical," she says. "I'd like both of my kids to remain kids as long as possible until they actually have to become grown-ups, so I prefer none of them become professionals before adulthood."

Connelly may have the sheen and the guardedness of a Hollywood veteran but she spends far more time in the outdoors than her pallor suggests. She, her boys and Bettany spend most weekends and all summer at their country retreat four hours north of New York. "We go with our kids and do a significant amount of backpacking and long, multi-day hikes, going out with a little tent and sleeping bags and stoves," she smiles. "It's so much fun.

"Dirt roads, mountains, woods, it's great; we love it."