of the 21st century-- astrophysicist, hayden planetarium director, and nova science now host neil degrasse tyson. i'm maria hinojosa. this is one on one. neil degrasse tyson, thank you so much for being with us. >> it's about time you had me on the show. >> hinojosa: just in case people don't know who you are... >> okay. >> hinojosa: but of course, everybody knows. you are the most famous astrophysicist in the country... african american astrophysicist. you are the director of the hayden planetarium in new york city. you're the host of nova science now. and you write books, and you dance, too. >> i once danced. not much anymore. that was an earlier chapter in my life. and odd that you would mention my ethnicity there. and i say that because i once thought about that. and i realized that i may be the most visible scientist of any discipline, of any ethnicity, of any skin color, in america today. and the reason why i went through that mental exercise was because there i am trying to bring the frontier of science to the public, and i said, "i don't want to do that alone. i want some others th