Humanity's "Backup Disc" on Israel's Lunar Craft Holds a Ton of Weird Info

The Israeli spacecraft Beresheet, set to be the first-ever non-government-owned moon lander, is carrying precious cultural cargo: a 30-million-page backup disc of humanity’s collective knowledge, including the contents of one very important website. Dubbed “The Lunar Library” by its creator, the Arch Mission Foundation, the solid-state nanotechnology storage device looks like a standard-sized DVD, much like one that might play the film Step Brothers. But instead of Step Brothers, it contains an exhaustive archive of science and culture.

On Thursday night, Beresheet, owned by Israeli non-profit SpaceIL, broke free of Earth’s gravity aboard a SpaceX Falcon 9 rocket upon its hottest reentry ever. In the days since, Beresheet — Hebrew for “in a beginning” — has entered the moon’s orbit, where it will maneuver until April, when it will attempt to land on the moon’s surface.

The mission itself will be quite short, possibly only lasting a few days while the lander uses its propulsion system to “hop” to a second landing site. But the AMF backup disc for humanity could easily remain on the moon long after all humans on Earth have gone extinct.

The top few layers of The Lunar Library can be viewed with a microscope, while the deeper layers contain data files compressed onto 21 thin layers.
The top few layers of The Lunar Library can be viewed with a microscope, while the deeper layers contain data files compressed onto 21 thin layers.

How The Lunar Library Fits on a DVD

The Lunar Library, which superficially resembles a standard 120-millimeter DVD, actually comprises 25 nickel discs, each of which is only 40 microns thick, stacked on top of each other. (A human hair is between 60 and 120 microns thick). Needless to say, AMF packed a ton of information onto the 100-gram — less than a quarter pound — disc:

The first four layers contain more than 60,000 analog images of pages of books, photographs, illustrations, and documents — etched as 150 to 200 dpi, at increasing levels of magnification, by optical nanolithography.

The first analog layer is the Front Cover and is visible to the naked eye. It contains 1500 pages of text and images, as well as holographic diffractive logos and text, and can be easily read with a 100X magnification optical microscope, or even a lower power magnifying glass.

The next three analog layers each contain 20,000 images of pages of text and photos at 1000X magnification, and require a slightly more powerful microscope to read. Each letter on these layers is the size of a bacillus bacterium.

Below the increasingly tiny images on the analog layers lie the digital layers, which contain about 200 gigabytes of data, compressed down to 100. And for any alien life-form fortunate — or unfortunate — enough to stumble upon The Lunar Library, the analog layers include the world’s longest homework assignment in the form of a “Primer,” which describes millions of concepts in multiple languages. The analog layers also include “a series of documents that teach the technical specifications, file formats, and scientific and engineering knowledge necessary to access, decode and understand, the digital information encoded in deeper layers of the Library.”

What’s Really in the Lunar Library?

Importantly, these deeper layers contain the entire contents of Wikipedia, as well as 25,000 books, ranging from fiction novels and non-fiction books to technical science and engineering textbooks.

The AMF describes The Lunar Library as an attempt to preserve human knowledge in the event of catastrophe, as well as a way to possibly communicate with aliens who come across it. And while the Library is ostensibly a comprehensive accounting of human history and knowledge, it admittedly comes from a particular perspective:

Also in the analog layers, are several private archives, including an Israeli time-capsule for SpaceIL, containing the culture and history of Israel, songs, and drawings by children.

The matter of who exactly gets to be humanity’s representative to the stars has become a hot matter of debate in recent years, as advanced communication technologies have made it possible to beam all sorts of information including electronic dance music and Doritos commercials, into space:

In 2008, when a Doritos ad was beamed toward Ursa Major, about 42 light years from Earth, it seemed that all bets were off. So at least AMF is compiling an archive of human knowledge to be our ambassador to the stars, rather than a bizarre commercial. And let’s be real: Wikipedia contains just about every bizarre corner of the human experience that has ever been documented. In this sense, AMF has created a fairly inclusive document of humanity.

The Lunar Library isn’t AMF’s first shot at sharing human knowledge with our neighbors. A small version of the archive flew aboard the Tesla Roadster that SpaceX launched aboard a Falcon heavy rocket in 2018, and it’s presumably going to remain there until the rocket is salvaged for parts by aliens. In the case of The Lunar Library, though, the disc will just sit in one place until someone picks it up and pops it into a computer. And while it doesn’t contain any MP4 files, at least some hapless alien will be able to read the Wikipedia synopsis page for Step Brothers.