but you brought up carl sagan. what was your relationship? >> guest: it wasn't, you do, i think the press occasionally overstates what the relationship was. i met him when i was 17, just an anonymous high school kid. but what was remarkable about that, that he was already famous soviet not yet done cosmos but he is already famous, had been on johnny carson, the tonight show multiple times. cover stories in parade magazine. he was already well known and i'd apply to cornell where he was on the faculty and unknown to me the admissions office sent my application to him to get his comment and reaction. .. the bus and went from new york in december in the winter, cold and he met me outside the building show me the lab. reach behind him. ever forget this, didn't even have to look. signed it to me, i said wow, that's bad a. >> the book that you have written. i still have that book. it says to future astronomer. carl. so at the end of the day, he drives me back to the bus station and it begins to snow. not an uncommon thing in new york. then he says,