More than 11 billion miles away from Earth, two small discs are rocketing through space at speeds in excess of 37,200 miles per hour. Their journey started in 1977, when NASA sent the two Golden Records into space, bolted to the Voyager 1 and 2 spacecraft. The records contain a treasure trove of information about our home planet, including sounds, songs, and images from Earth.

At the moment, the records are just hangers-on to the Voyagers’ current mission, to document the outer limits of the Sun’s influence on the Solar System. By 2030, however, both Voyagers will cease communicating with NASA, but they will continue sailing through space. At that point, they will have only one mission: continue on with the Golden Records in hopes that another advanced civilization, somewhere in the galaxy, intercepts them.

The audio contained on the record should be fairly easy to decode — extraterrestrials will only need to figure out the correct speed and rotation of the disks, place the included stylus within the grooves of the record, and jam out to Chuck Berry, Mozart, and the sounds of the Earth.

Unscrambling the images contained on the record — that’s going to be a little bit harder.

You might think that the images were included in some printed or digital form, such as a .jpeg or .tiff. But back in 1977, there was no technology available to put images on analog disks. Voyager’s computer systems could only hold 69 kilobytes of information, barely enough for one image, let alone 115. So NASA invented a way to include image data on the LPs.

By projecting images onto a screen, recording them with a television camera, and then turning those video signals into audio waveforms, the images could be properly pressed onto the records. The reversal process — turning that image data back into images — is what any extraterrestrial (or curious human) would have to figure out how to do.

Luckily, NASA engineers included instructions on the cover of the record to help decode the data contained on the disks. And without access to 1970’s technology and expertise, the guidelines were tricky for us to follow. But after learning a lot from the DIY community, including from Ron Barry, who wrote his own in-depth guide to decoding the disks, we were able to see the data.

We tried two alternate methods using Microsoft Excel and Python — and were amazed to find that even 40 years later and with completely different technology, it was still possible to unravel images from the audio waves.

Maybe extraterrestrials will be able to figure this out after all.

Take a look at the video to see how we decoded the Golden Record — and maybe give it a try yourself.