"For so long we thought they only did bad things, like zap people," says Space Center's Teresa Ehrman, citing such global atrocities as the bubonic plague and polio. "But there are good germs and bad germs. We're showing how they've both hurt society and helped the environment."

At the exhibit, kids get a chance to be a contestant on a game show called "Microbe Man" or to gobble up an oil spill in a video game. For children raised on game stations, Ehrman says, this approach is a necessity.

"Today, kids have to really experience something to learn and understand it. And it will have a much better effect if they're having fun. We kind of sneak in the learning part."

One display, titled "Eat My Shorts," shows how scientists are working on a "microbe cocktail" that will -- no joke -- eat away at an astronaut's soiled cotton-and-paper underpants. (Well, what did you think they do on those long space walks? Just zip open their space suits?)

"Microbes have always been a critical part of the space program," Ehrman says. "On early moon missions, they were very concerned [about] what they might bring back and how it might hurt people on earth."

And while alien microbe invaders seem the stuff of cheesy '50s sci-fi movies, who's to say that John Glenn isn't harboring some germ of mass destruction in his system? This exhibit does have the corporate support of Pfizer, the makers of Viagra. Coincidence? We think not…