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Nerds are rejoicing over Neil deGrasse Tyson hosting the new TV show "Cosmos: A Spacetime Odyssey."

The esteemed astrophysicist is 55 and married with two teenage kids, and he's attracted a gaggle of admirers.

"It started about 14 years and 25 pounds ago," Tyson told People.

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That's when Tyson was featured in the magazine's Sexiest Man Alive issue as the Sexiest Astrophysicist.

Now, with his new show on Fox and National Geographic, he's garnered a whole new group of admirers, mostly on Twitter, where he has 1.7 million followers.

"I'll Tweet something that's interesting and a little bit mind-blowing, and I'll get responses like, 'I just had a nerd-gasm,' " Tyson told People. "I say, whatever gets people interested in the universe! I'm happy to serve as a conduit to the cosmos."

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Naturally, Tyson, the director of the Hayden Planetarium in New York City, has a scientific explanation for his fans' affection.

"When you tell people something that's intellectually delectable, they can feel sensually towards it," says Tyson. "But I think at the end of the day, the object of their affection is the universe."