In the exclusive extras below, the beloved science rock star talks about his childhood curiosity about the universe, Carl Sagan, and his experience on 9/11 in downtown Manhattan.

On discovering the stars as a child, on a family trip to the Hayden Planetarium. “The stars came out, and I was hooked. How could you not be?… I was helpless in the presence because of the boundlessness of that night sky. Some people fear the unlimited horizon that is exploration. If you do, then you retreat; you say, ‘I’m afraid of that. I want to just go back to my bed and my warm covers and my chocolate chip cookie and glass of milk.’ I was not like that. I wanted to learn more about what I didn’t know…. My curiosity was large enough to leave me in intellectually unstable places. It was a driver to get [me] to learn more.”

On not trying to fill Carl Sagan’s shoes.“That was an important discussion [early on]. Yeah, I can say ‘billions and billions’ like the best of them. And I realized—and I think others agreed—that I could try to fill his shoes and perhaps fail, [or] I could be a really good version of myself. And no one can say I failed at that.

“The Sagan influence was not his delivery. It is the thematic foundations of what Cosmos was and its relationship to the viewer. So now I am in that host role, and I’m connecting with you, the viewer, in all the ways I know how and have done up until now.”

On his experience on 9/11 in downtown Manhattan, and why “you will never find scientists leading armies into battle.”“I was at home looking out the window. Yeah, it was right there. I watched it unfold: One plane in the North Tower, okay, that’s a really bad accident. And then a second plane hits, and everyone can do the calculations. Yes, I saw the second plane hit. In fact, I was filming the fire in the North Tower on my camcorder, using my high-zoom lens to assess, is it going to tip over? Because I live closer to Ground Zero than the height of the towers. If they were to fall at their base toward me, what would I do? In retrospect, it was clear that the tower could not have fallen at its base because it was not destabilized at its base…. And while I’m watching this happen, the South Tower gets hit, and then you see the fireball. It’s all in the camcorder….

“It was an odd kind of—I may have been the closest scientist to that event. And when I sent out an email that evening to my colleagues and family, I just sort of described what I saw analytically. Now, how did I feel? What I know is, when you have a cosmic perspective, when you know how large the universe is and how small we are within it—what Earth looks like from space, how tiny it is in a cosmic void—it’s impossible for you to say, ‘I so don’t like how you think that I’m going to kill you for it.’ You will never find scientists leading armies into battle. You just won’t. Especially not astrophysicists—we see the biggest picture there is. We understand how small we are in the cosmos. We understand how fragile and temporary our existence is here on Earth. We understand there are bigger problems we need to solve as a species than what God you pray to.

“Any time scientists disagree, it’s because we have insufficient data. Then we can agree on what kind of data to get; we get the data; and the data solves the problem. Either I’m right or you’re right or we’re both wrong. And we move on. That kind of conflict resolution does not exist in politics or religion. It does not exist in so much of what we do as human beings on this Earth that it’s almost tragic.