If you were tasked with creating a message that could convey the human experience to hypothetical alien life forms, what would it say?
In December 1976, astrophycisist and science populizer Carl Sagan was faced with that daunting question. John Casani of NASA's Jet Propulsion Laboratory (JPL) had approached Sagan and asked him to assemble an interstellar message that would accompany the Voyager spacecraft when the two probes launched on their flyby missions to Jupiter, Saturn, and Saturn's moon Titan.
Sagan loved the idea, and recruited the help of Search for Extratrerrestrial Intelligence (SETI) founder Frank Drake while at an academic conference the following month. The pair didn’t have much time: Voyager 1 and 2 were scheduled to launch late summer 1977, with or without messages from Earth.
Sagan and his team worked fast. With Frank Drake as technical director, author Ann Druyan as creative director, music editor Timothy Ferris as producer, artist Jon Lomberg as designer, and artist Linda Salzman as greetings organizer, they consulted scientists, philosophers, and creators to pull together technical content in just a few weeks.
The result was The Sounds of Earth, also called the Voyager Golden Record, a collection of music, images, and sounds meant to distill what it's like to live on our planet. When the probes launched in 1977, they each carried a copy of the Golden Record—the equivalent of four sides of a 12-inch LP—as well as a record player and instructions on how to play the record. Today, those phonographs still hurtle into deep space. As of now, Voyager 1 and its accompanying record are the farthest from Earth of any human-made object. Voyager 2 continues to study the outer reaches of the solar system. It's entirely likely that both space probes, and the records they carry, will outlast the species that created them.
Meanwhile, back on Earth, public interest in the record continues to grow. In 2016, a Kickstarter launched with the aim of making copies of the record available to the public for the first time ever—not even Sagan himself had a physical copy. The Golden Record represents an attempt by Sagan and his team to define what it means to be human, a struggle that continues to compel us today. In light of that, let's take a look at one of the most fascinating records ever put together by our species.
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The message is intended for humans, not just aliens
Although the record was designed as a message to the stars, everyone involved knew it was unlikely to ever be heard by aliens. The chance of a spacecraft randomly straying into another solar system within the next ten billion years is tiny. In Murmurs of the Earth, Sagan's book about the record, he makes the analogy, “It is a little like randomly throwing a dart in the dark in Madison Square Garden, to whose walls are affixed twenty balloons. There is some chance of puncturing a balloon, but the likelihood of success is stupefyingly small.” For the records to reach a solar system inhabited by aliens capable of intercepting and decoding it is even smaller still.
But the records are also a time capsule for Earthlings, a message intended to unify humanity as one planet in 1977. As project consultant B.M. Oliver wrote in Murmurs of the Earth, “There is only an infinitesimal chance that the plaque will ever be seen by a single extraterrestrial, but it will certainly be seen by billions of terrestrials. Its real function, therefore, is to appeal to and expand the human spirit, and to make contact with extraterrestrial intelligence a welcome expectation of mankind.”
The welcoming message signed by President Jimmy Carter is intended for aliens and humans alike. He writes,
"This is a present from a small distant world, a token of our sounds, our science, our images, our music, our thoughts, and our feelings. We are attempting to survive our time so we may live into yours. We hope someday, having solved the problems we face, to join a community of galactic civilizations. This record represents our hope and our determination, and our good will in a vast and awesome universe."
The content is meant to be both inclusive and unambiguous
The record holds 118 images, nearly 90 minutes of music, greetings in 55 human languages, as well as the sounds of whales, surf, thunder, birds, and other representations of the natural world. Together, this media is meant to encompass what it means to be on Earth.
The most important content is a diagram that explains how to play the record, encoded in the record content and also etched onto the surface.
The rest of the images try to condense information about Earth, including its environment and creatures, the solar system, humans, and scientific knowledge. The curation team did its best to ensure each image served multiple purposes. Photos include the Golden Gate Bridge, the Taj Mahal, a page from Isaac Newton’s The System of the World, a photograph of Olympic sprinters, and demonstrations of eating, licking, drinking, and human reproduction. However, at NASA's request, the record doesn't contain images of men and women in the nude.
The images also contain purely scientific concepts like the structure of DNA, physical unit definitions, and images of planets within the solar system.
In total, there are twenty-seven pieces of music on the record, covering a range of genres. The musical selections include “Blind was the Night” by Blind Willie Johnson, Chuck Berry’s “Johnny B. Goode,” the Georgian chant “Tchakrulo,” jazz by Louis Armstrong, and Scottish bagpipes. The music does not include “Here Comes the Sun” by the Beatles, as the Golden Record team couldn’t get permission from the Beatles' record company, despite the band's support of the idea.
Phrasing for each spoken greeting on the record was left for the speakers to decide. The messages range from “Are you well?” to “Friends of space, how are you all? Have you eaten yet? Come visit us if you have time,” to “Greetings to the inhabitants of the universe from the third planet Earth of the star Sun.”
The final package contains 12 minutes of sounds from Earth, an audio postcard including a kiss, EEG brain waves, storms, volcanoes, rocket launches, waves, and animals.
The Golden Record is just one of many messages humans have sent to space
Every message on a spacecraft is a hitchhiker, carrying whispers of our humanity as an adjunct to the primary mission. The golden records are the highest profile messages, but they weren’t the first to catch a ride on a spacecraft.
Before they collaborated on the Voyager project, Sagan and Drake paired up to create gold-anodized aluminum plaques mounted on the Pioneer 10 and Pioneer 11 spacecraft, the first messages destined for deep space. These plaques are far simpler than the messages included in the Golden Record. They have illustrations of a nude man and women, a diagram of the hydrogen molecule, and a pulsar map marking the position of the solar system. Controversy over including nude figures on the Pioneer plaques led NASA to avoid nudity on the Voyager record.
The most recent spacecraft destined for deep space, New Horizons, does not contain any equivalent welcome message. Instead, it has a pinch of Pluto-discoverer Clyde Tombaugh’s ashes, a CD of over 400,000 names of space enthusiasts and photos of the spacecraft’s personnel, state quarters from Maryland (where the spacecraft was built) and Florida (where the spacecraft was launched), U.S. flags, a piece of Virgin Galactic’s SpaceShip One, and a 1991 stamp declaring, “Pluto: Not Yet Explored.”
The 'golden' records are actually copper
The records are gold-plated copper phonographs, etched to encode them with images and sounds. At astronomer A.G.W. Cameron’s suggestion, each record has a small radioactive anomaly on their surfaces. A spot of uranium-238 two centimeters in diameter is electroplated on each record. The radioactive material serves as a chemical stopwatch, the half-life of radioactive decay counting down time since the records were manufactured.
The records are safely tucked inside protective aluminum cases—and in all likelihood will remain there long after humans and the planet we live on are gone.
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