Carl Sagan And Ann Druyan's Ultimate Mix Tape

Carl & Annie's Earth Guide For Aliens A montage from Sagan and Druyan's golden record.

Enlarge this image toggle caption Druyan-Sagan Associates, Inc. Druyan-Sagan Associates, Inc.

Voyager 1 And Voyager 2 Distance From Earth This map is not to scale, but shows approximately the distance Voyager 1 and 2 are from Earth.

This is a love story. And, oddly enough, it starts with an interstellar space mission and a golden record.

Toward the end of the summer of '77, NASA launched two spacecraft as part of the Voyager Interstellar Mission. On board each craft was a golden record that included, among other things, the sound of a kiss, a mother's first words to her newborn child, music from all over the world, and greetings in 59 different languages. The spacecraft were designed to take close-up pictures of Jupiter and Saturn, then continue into the great expanse of space beyond our solar system. The records on board were meant to survive for a billion years, in the hope that some day, against enormous odds, they might cross paths with an alien civilization.

So how do you decide what to put on the ultimate mix tape of the human experience? What do you do if you have one shot at describing humanity to an unknown life form? That was the charge of Carl Sagan — astronomer, astrophysicist and famed popularizer of science. Of course, Sagan had a lot of help, including the creative director of the project, Ann Druyan.

"It was a chance to tell something of what life on Earth was like to beings of perhaps 1,000 million years from now," Druyan says. "If that didn't raise goose bumps, then you'd have to be made out of wood."

For Druyan, though, the summer of 1977 and the Voyager project carry a deeply personal meaning, too. It was during the Voyager project that she and Sagan fell in love.

After searching endlessly for a piece of Chinese music to put on the record, Druyan had finally found a 2,500-year-old song called "Flowing Stream." In her excitement, she called Sagan and left a message at his hotel. At that point, Druyan and Sagan had been professional acquaintances and friends, but nothing more. But an hour later, when Sagan called back, something happened. By the end of that call, Druyan and Sagan were engaged to be married.

"We both hung up the phone, and I just screamed out loud," says Druyan, "It was this great eureka moment. It was like a scientific discovery." The first of the Voyager project's two spacecraft launched on Aug. 20, 1977. Druyan and Sagan announced their engagement two days later. They married in 1981, and were together until Sagan's death in December 1996.

The Full Record toggle caption NASA Center: Jet Propulsion Laboratory Listen To 'Flowing Streams,' The Song That Brought Ann And Carl Together Explore The Full Record

But the evidence of their love has taken on a life of its own. Not long after that serendipitous phone call, Druyan had an idea for the record: They could measure the electrical impulses of a human brain and nervous system, turn it into sound, and put it on the record. Then maybe, 1,000 million years from now, some alien civilization might be able to turn that data back into thoughts. So, just a few days after she and Sagan declared their love for each other, Druyan went to Bellevue Hospital in New York City and meditated while the sounds of her brain and body were recorded. According to Druyan, part of what she was thinking during that meditation was about "the wonder of love, of being in love."

And the gold records? They're still out there with their offer, to whomever might stumble across them, of a human body newly in love.

"Whenever I'm down, " says Druyan, "I'm thinking: And still they move, 35,000 miles an hour, leaving our solar system for the great open sea of interstellar space."

Produced by Soren Wheeler