Neil deGrasse Tyson's celebrity proves he's keeping science mainstream

In this week's Sunday Sitdown, Willie Geist joins astrophysicist Neil deGrasse Tyson inside his famed office at the Hayden Planetarium. The "StarTalk" host opens up about his passion for the stars that began at a young age, how he pushes back against people who doubt the severity of climate change, and how he has "hope for the world" that science is becoming mainstream. (Aired 10/1/17)