Cosmologist Carl Sagan was legend at communicating complicated science to the masses, but what is arguably his most famous message wasn’t designed for humans.
That message is a collection of images, sounds, and mathematical symbols recorded on a gold-plated phonograph disc that’s still flying through space today, Monday, Nov. 9 — what would have been Sagan’s 81st birthday. It’s nicknamed the “Golden Record,” and if any aliens are out there, it may serve as their first physical encounter with humankind.
Sagan is probably best known for hosting the PBS TV series “Cosmos,” which artfully explained the wonders of the universe.
But before his death in 1996, Sagan was also hailed as a pioneer of early Solar System exploration, a powerful mentor (including to a young Neil deGrasse Tyson, who later rebooted the “Cosmos” TV series), and a key contributor to some of NASA’s most iconic missions to other worlds.
One of those missions involved launching a pair of space probes — Voyager 1 and Voyager 2 — beyond the solar system. Since NASA knew the spacecraft would travel farther than any manmade object in history, the space agency decided each robot should carry a message in case an intelligent civilisation bumped into one of them. Sagan led the committee tasked with putting that message together.
Sagan and others chose 115 images from Earth and several natural sound recordings from things like wind, whales, and thunder. They also added musical selections from different cultures and time periods, and greetings recorded in over 50 languages. There’s also a message from former president Jimmy Carter. (You can check out a full list of the tracks recorded on the record if you’re curious.)
The Voyager spacecraft launched in 1977, both carrying a copy of the Golden Record. Voyager 1 passed out of our solar system and into interstellar space in 2012. It’s about 12.4 billion miles away from the sun right now, or roughly 3 times the distance from Earth to Pluto. (Voyager 2 is about 10.2 billion miles away.)
The Voyager spacecraft may drift aimlessly through space forever, and aliens may never hear the record. But Sagan promoted the hopeful and poetic nature of the mission:
“The spacecraft will be encountered and the record played only if there are advanced space-faring civilizations in interstellar space,” Sagan once said. “But the launching of this bottle into the cosmic ocean says something very hopeful about life on this planet.”
Sagan is also the guy who insisted Voyager 1 should take a final parting shot of planet Earth from 4 billion miles away, just as the spacecraft hurtled to the farthest reaches of the solar system and beyond.
Which is why we have this iconic “pale blue dot” photo:
Sagan described the photo in his aptly named book “Pale Blue Dot“:
Look again at that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilisation, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there–on a mote of dust suspended in a sunbeam.
You can watch Sagan further explain the importance of the Voyager spacecraft in the video below:
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