Forty years ago this past Sunday, Voyager 2 launched from Cape Canaveral, Florida. Its twin, Voyager 1, launched Sept. 5. Coincidentally, I was born right between those launches, which means that “we both started our journeys into nowhere at the same time.”

That’s actually what I said while interviewing several NASA scientists and Tim Ferris, who created the Golden Record that’s aboard Voyager. They all laughed.

“That bad, huh?” said Carolyn Porco, Ph.D, a planetary scientist who worked on Voyager and now leads the imaging team for the Cassini mission that’s exploring Saturn.

I quickly revised: Both Voyagers and I started “our journeys into the unknown” at the same time, I said.

It’s amazing to think that the Voyager spacecraft have been exploring for my entire life. As I type these words, Voyager 1 is 12,948,526,917 miles from earth, though it’s traveling at more than 38,000 MPH, so that changed before I could even type it. (Here’s real-time data.)

That means Voyager 1 now in interstellar space, farther than a human-produced object has ever gone before, and may possibly be “the only evidence that we ever existed,” as someone says in The Farthest: Voyager in Space, which airs tonight on PBS at 9 p.m.

The documentary, which debuted at the Tribeca Film Festival, surprised me not just with the information about Voyager, but with how well it told the story. It’s beautifully made and brings us into the wonder and awe of the solar system, but also into the tension and struggle of the efforts to get the spacecraft there. (The Fartherst was written and directed by Emer Reynolds, and is produced by John Murray and Clare Stronge.)

Still listening to, and learning from, Voyager

Ed Stone, who has been the project scientist for NASA’s Voyager mission since 1972, and previously directed NASA’s Jet Propulsion Laboratory, told me that he still listens to Voyager for hours a day—four, six, or eight hours, depending upon availability of antennas. The signal strength is 10^-18 watts, he said.

“We have left the bubble and entered the space between the stars,” he said. “Outside the bubble, we are in the material that has come from the explosion of other stars.”

Voyager broadcasts 24/7, but will run out of power eventually, possibly in about 10 years.

Stone told me that the story told about Voyager in The Farthest “really is more than just science. There is a larger theme of humanity, exploring.”

Carolyn Porco agreed, and said the film is “more of a social history than a real exploration of the science we did,” but she said that’s important, especially because of how little some people know about space exploration.

“Certainly with the Pathfinder, there were people, young people who didn’t know that we had landed on Mars in 1976—20 years earlier, I couldn’t believe it. They thought that was the first time we landed on Mars,” she said. “So, I think they have a lot to learn in the history of the space program, and this will be a good education for them. The movie does that: it just really elicits the emotions of the people being interviewed, and people will tap into that and realize what it what a human enterprise it was.”

Tim Ferris, the producer of the Golden Record that’s aboard the spacecrafts, said that he wouldn’t change a thing about the record or how it was made now, despite the advanced technology we have today compared to the mid-1970s. That’s because he had to certify it “to last at least a billion years,” and added, “The question with Voyager is no how much information you pack into it, it’s how long it lasts. Voyager’s a time capsule.”

Ferris has frequent contact with filmmakers interested in learning about his work, but those making The Farthest: Voyager in Space were different.

“I get interviewed a lot, but I developed an affection for the people making the film—it struck me that these were people who might do something memorable,” he told me. “In any creative art, you have people who want to do something that’s like things that were done before. We don’t have have much money, but with the money we have, we can make something that’s sort of like this and a network will air it.”

“That’s a sin,” Ferris said. “It doesn’t matter how little money you have. Your goal should be to do something nobody’s done before. Otherwise, why would you wreck years of your life doing it?”