In 1977, NASA launched Voyagers 1 and 2 from Cape Canaveral, Florida into space to embark on a grand tour of the far reaches of our solar system. Mounted on board each probe was a 12-inch gold-plated copper disk—a cosmic “message in a bottle” engraved with sights, sounds, and depictions of life on Earth, collectively known as the Golden Records—on the slim chance some far-off alien civilization might discover them. And in Disney and Pixar’s animated film Elio, in theaters June 20, that’s exactly what happens when main character Elio encounters aliens who believe he is Earth’s leader.
“It’s meant to be a sort of a letter of introduction to any culture who might find the probe,” says Bethany Ehlmann, a planetary scientist at the California Institute of Technology and a 2013 National Geographic Emerging Explorer, of the real-life Golden Records. Though these gilded greetings were partly intended for an alien audience, they mostly served as a message to humans and our tiny blue marble planet. “It’s a love letter to Earth and all that we have come through to get to the point where we could send these probes to understand our solar system.”
But where are the Golden Records now—and how much longer are they intended to last in space? We spoke to the experts, including Ehlmann, to find out.
Humanity’s interstellar mixtape
When tasked with figuring out what to include in the intergalactic mixtape aboard the Voyager probes, renowned astronomer Carl Sagan assembled a team of scientists, artists, and engineers. For a true depiction of life on Earth aboard humankind’s most distant physical emissary, the team included a variety of sounds associated with daily life and nature, like bird calls, humpback whale songs, children’s laughter, footsteps, heartbeats, brain wave scans, and a kiss. There are also 90 minutes of music contained on the disk, including Western classical compositions from Mozart, Bach, Beethoven, and Stravinsky, Senegalese percussion music, Australian Aboriginal songs, and Chuck Berry’s “Johnny B. Goode.”
(The close of cosmos, and golden voices in the stars.)
The carefully thought-out record, designed to endure space travel for billions of years, also consists of spoken greetings in 55 modern and ancient languages, as well as 115 analog-encoded photographs of Earth and its inhabitants.
Engraved on the cover of these records is a map to help find one’s way to Earth relative to nearby known, flashing, dense cores of stars called pulsars. There are etched diagrams of a hydrogen atom—the most common element in the universe—and instructions for playing each record. Each disk is enclosed in a protective, gold-plated aluminum jacket, together with a cartridge and a needle to play it.
“The spacecraft will be encountered and the record played only if there are advanced space-faring civilizations in interstellar space,” Sagan, leader of the Voyager Golden Record project, wrote. “But the launching of this ‘bottle’ into the cosmic ‘ocean’ says something very hopeful about life on this planet.”
(Dear Voyagers: How your billion-year journey carries true love.)
A far-out cosmic road trip
Over the years, the Voyager probes flew by the solar system’s most distant four planets at a rate of 35,000 miles per hour, sending back detailed views of Jupiter, Saturn, Uranus, Neptune, and their moons. Voyager 2 flying by Uranus and Neptune is the only time humanity has seen these worlds up close.
After completing their primary missions to collectively fly by all four outer planets in 1989, the twin probes kept chugging along through the vast outer reaches of the solar system. Voyager 1 and 2 exited the solar system and entered interstellar space in 2012 and 2018, respectively.
At more than 15 billion miles from Earth, Voyager 1 has become the most distant human-made object in space. Voyager 2, in second place, is now about 13 billion miles away. The interstellar environment they’re in contains a stew of cosmic gas, dust, and rays. The twin Voyager probes are equipped with radiation-resistant parts, but the onslaught of charged particles in their current neck of the woods still pose a threat to their aging electronics.
Both Voyager spacecrafts are still collecting and sending back data, updating humans on their intergalactic adventures, albeit slowly—it takes nearly 20 hours for these signals to reach Earth, given the immense distance they need to travel.
We’re now reaching the end of the Voyager missions, as the twin probes’ plutonium power supplies are running out of juice. The Voyager team is attempting to extend their lifetime for as long as they can by shutting down non-essential instruments like heaters to conserve power. “More than 47 years into the mission, there’s very little power left,” says Suzanne “Suzy” Dodd, the current project manager for the Voyager missions. “The goal of the mission is to get it to 50 years.”
Even after the probe’s science mission ends, though, the Golden Records will keep quietly drifting further and further into the cosmic abyss, likely for millions and even billions of years.“Long after we’ve lost communications with the spacecraft, it’ll still be traveling with this record—a time capsule,” Dodd says. She remarks that it’s exciting “to think about a little piece of us, a little piece of what Earth and humanity is all about, traveling around the center of our galaxy to be found by whatever being might be out there.”
But, as Dodd points out, there are enormous physical and chronological distances involved. It’s going to take around 40,000 years for the probes to drift into the vicinity of any other star system, when Voyager 1 will pass within 1.6 light-years of the star Gliese 445. Around the same time, Voyager 2 will be within 1.7 light-years of the star Ross 248.
The legacy of the Golden Records
The Golden Records have left a huge cosmic impact. According to Ehlmann, most spacecrafts that followed the Voyager mission included some sort of message from our Earthly abode. “People sometimes think of science as a cold and calculating endeavor, but really it’s the expression of curiosity and awe,” she says. “It’s an ability to leave your mark in the universe.”
And almost fifty years after they first took flight, our pair of plucky robot emissaries to the stars continues embarking on the deepest journey ever into space.
“Who knows? The Voyager probes, a million years from now, may end up in some alien museum,” Ehlmann says. “It’s exciting to imagine.”