We already knew the delights of Neil deGrasse Tyson's inimitable Twitter presence . But after viewing the latest video of a series in which Tyson responds to fan questions to promote his National Geographic show StarTalk , we're even more enamored of the astrophysicist-cosmologist-author.Viewer Ronnie T., like many among us, wants to know: "Is there anything different about having sex in space?" Tyson begins his answer by distinguishing between being in space and being weightless; you can be both in space and in an environment with greater-than-zero gravity, such as a space station. He then goes on to describe the challenges of weightless intimacy: "You need things like straps. There are probably some people who are fully equipped with this anyway — but I'm just saying," he laughs. "You're there, floating in space, and then you move toward someone, and they just sort of bounce off. The movement is preserved; there's no friction." Well done with the subtle bondage reference, Dr. Tyson.Bouncing bodies aren't the only challenge to astronaut sex: As we've written before , in microgravity, blood pools around the head and chest rather than downward (i.e. in the penis or clitoris), making arousal potentially more difficult, though not impossible. Tyson ends his video on a hopeful note: "Bring a lot of leather belts to keep things strapped down, and you'll be just fine," he advises. We'll remember that as we pack for our next intergalactic mission.