Back in February, my mother and I were at the Sydney Opera House to share a moment seven years in the making. In a tented temporary theater just overlooking Sydney Harbor, we clutched each other’s hands tightly as we used to when I was a little girl growing up Ithaca, New York.

I was about to see an early screening of the first episode of the television series my mother Ann Druyan spent almost a decade writing, producing and directing, Cosmos: A Spacetime Odyssey. It was conceived as a way to carry on the legacy of my late father, Carl Sagan, a continuation of the show they made together before I was born — a love letter to his memory.

From the moment I saw "CS," my father’s initials, emerge from the Ring Nebula and expand into the word "Cosmos” in that cinematic opening-credit sequence, I was overcome with many emotions, not least of all pride.

Every Sunday for the past three months, I have had the great pleasure — like so many others around the world — of experiencing a kind of secular sermon on our place in the universe, the history of our species and a hopeful vision of our collective future, all written by my very own mom.

There was another early screening of Cosmos this past Wednesday for the show’s final episode, “Unafraid of the Dark,” at the Paley Center for Media in Manhattan. That afternoon, I sat down with mom in her hotel room to discuss entering the Twitter world, the relative coolness of the Spaceship of the Imagination and how it feels to do the show without my dad.

Sasha Sagan: I know that you tweeted as @CosmosonTV for the first time recently, and Nick [Sagan, Sasha’s half-brother] helped you. I was thinking a lot recently about Dad getting newspaper clippings from Burrelles, [the service that would send you articles you were mentioned in back in the days before Google] with the little manila tabs. I’m just curious about how Twitter feels versus getting paper in the mail.

Ann Druyan: There's no difference, but I remember that the handwritten letters were great. Carl received them, as the archives will attest, from people all over the world. But the Burrelles clippings were really from writers — from newspaper reporters, mostly journalists. On Twitter, it's so exciting to watch the show and realize people all over each time zone are reacting in the moment. I would see, "My kids want to be scientists. This is the only thing our family ever does together. We watch Cosmos." What a thrill that is.

You and Dad often talked about the species coming of age, and this 13th episode is called “Unafraid of the Dark,” which is very much a part of growing up. I’m curious how much you feel like this civilization has grown up, if at all, in these 30-some years since the original series.

Oh, I feel like we are growing up. When Carl and I were writing Cosmos with Steve [Soter] 35 years ago, we lived in a society that was overtly contemptuous of women, homophobic in the extreme and it kind of pretended to be getting over racism, and it really wasn’t. It was things that we take for granted today that were kind of impossible dreams back then. I feel like those changes are almost on a biological level because xenophobia — the fear of the other — is very deep. And to not only change [society's perception of] gender relationships in a species over a single lifetime like my own is the most radical change imaginable. That’s why I know that we’re going to get over this problem with climate change. I believe that so strongly, because we invented agriculture in response to climate change to begin with. And look what happened. Now, I believe that we still are dealing with the post-traumatic stress of the invention of agriculture, of living in cities, of having an unequal distribution of property.

Sasha Sagan with mother Ann Druyan in the 1980s. Image: Sasha Sagan

I do, too. And I think that’s why social media is, in a weird way, the most natural thing in the world. We used to live in villages where everybody knew what everybody else was doing. And now we all just have to adjust to living in the 7 billion-person village. How did you approach the show differently this time around?

I was really motivated to do this — first because there was so much hostility toward science about 10 years ago and public disdain for science really hurt me. Second, I really felt like, as a species, we were having really low self-esteem, and needed something which would kind of be an exposition of what I consider to be our proudest achievements, our most daring, audacious achievements.

I also wanted to keep Daddy’s flame burning brightly. I think more people love him today than ever 10 or 15 years ago. When I was pitching the show, I went to all these network execs and I would say, ‘You know, I know that there’s a yearning, a completely underserved yearning, on the part of the public to feel something spiritual, which people don’t have to lie to themselves in order to believe.

And the success of Cosmos has shown that — the fact that we won the ratings for last Sunday night (episode 12) for a global-warming episode is huge. As many people tuned into our show as The Bachelorette. That's no diss on The Bachelorette but wow, that's the world I want to live in, where people are really interested in how nature is put together, and where exploration and those values of reason are heroes and are given their dues.

In the beginning of the series, to see Jan Oort, Edmond Halley and Isaac Newton trending worldwide on Twitter, that is a form of gratification, which of course Daddy and I didn't get for the original series. A lot of the reviews for the original series were pretty snarky.

Really?

Oh, yeah. That’s why I didn't want to have the Ship of the Imagination in the new series. I was still smarting from these really nasty remarks about the Ship back in the '80s. But luckily, [executive producer] Seth [MacFarlane] turned me around on that one. Then I heard the Ship of the Imagination beat the Millennium Falcon at the Comic-Con [Starship] Smackdown a few years ago for the coolest ship. We were just beginning pre-production, and that made my heart soar. I realized that we were ready for a truly transporting experience in Cosmos.

The last episode of the first series aired on Dec. 21, 1980, right before the holidays. Do you remember where you and Dad watched it?

You know, I have to be honest: I have no recollection whatsoever. I remember countless times working with Daddy in the house we rented in Hollywood. I remember going over sequences on the video monitor, back and forth, changing words, talking and looking at shots, and figuring out what we liked and didn't like. But I don’t remember actually watching the show with Daddy.

The most resonant echo for me, and the thing that really got me choked up, was our very first shooting day on the new series, when we went to Monterey, California, and shot in the very same spot where the opening sequence of the original series was shot. I vividly recall being there with Carl and the feelings we had at that moment before there was a Cosmos. And here we were, setting out to do a new Cosmos. Many times I had to step away, just gulp and get that knot out of my throat.

Because when you don’t believe in an afterlife — and we don't — you realize that the person that you adored with all your heart is not there anymore. But when you come back to the place you were together, to do the work you did together, keep the faith and let the light shine, it's a tremendous feeling.

The final episode of Cosmos: A Spacetime Odyssey airs Sunday night at 8 p.m. ET on Fox. The series will be available on DVD and Blu-Ray starting Tuesday, June 10.