40 years ago Carl Sagan made a prediction about Voyager

One of the concerns that kept the legendary astronomer Carl Sagan awake at night was whether the aliens would understand us. In the mid-1970s, Sagan led a committee formed by NASA to assemble a collection of images, recorded greetings, and music to represent the Earth. Then they pressed The Assembly into golden discs and sent it across the cosmos on the backs of Voyager 1 and 2.

In a 1986 story Sagan wrote for Popular Science, he noted that

So it meant they probably wouldn’t be able to decipher the golden discs. But he was reassured by an underappreciated dimension of Voyagers’ message: the designs of the spacecraft themselves.

“We are tool makers”wrote Sagan. “This is a fundamental aspect, and perhaps the essence, of being human.” What better way to tell alien civilizations that Earthlings are toolmakers than by sending a living room-sized, aluminum-framed probe through the Milky Way.

Although both spacecraft were designed only to pass through Jupiter It is SaturnVoyager 2’s trajectory also launched it beyond Uranus It is Neptune. Despite countless bumps along the way – and thanks to the elite toolmaking skills of engineers at NASA -, the probe was in good enough shape to send back detailed images of these distant worlds. In 2012, Voyager 1 became the first interstellar spacecraft, followed soon after by Voyager 2.

Voyagers are too far away

Today, probes are 12-15 billion miles from Earth, still operational (despite facing recent communication difficulties), and navigating interstellar space. They are expected to continue transmitting data back to Earth for another year, or until their plutonium batteries run out.