Neil deGrasse Tyson: 'I want people to welcome science into their lives'

The host of National Geographic's StarTalk on how he chooses his guests, why his subject is nothing to fear - and what he wants from presidential candidates

Neil deGrasse Tyson wasn't able to watch the first Democrat presidential primary debate, but he knows what he wants from the candidates.

"I don't require that a candidate know science,' he says. "I require, when I vote, that the candidate knows when they don't know science, and uses that as the occasion to talk to their advisors. A leader is not necessarily an expert in everything they need to be an expert in to lead. The best leaders know when to follow."