One tiny storage medium for humankind

06 November 2025

How can the linguistic and cultural heritage of humanity be preserved? The idea that US company Barrelhand has come up with is to use a storage medium on the moon, and it’s launched a non-profit initiative specifically for this purpose. And the experts from ALTER I HTV, a subsidiary of the TÜV NORD GROUP, are playing a decisive role in this ambitious project.

With devastating wars, the persecution of minorities, environmental destruction, species extinction and global warming, it’s fair to say that, throughout human history, our species has not always shown consideration for the Earth – or for itself. At the same time, since its emergence Homo sapiens has come up with democracy and also brought philosophical and artistic responses to bear on the world and its own existence. A cultural heritage that needs to be preserved for future generations and that might give other life forms in the cosmos – if indeed there are any – a first impression of who we are or were.

Barrelhand has dedicated itself to this noble aim. And the Californian technology company has turned to a nano-engraving technology called NanoFiche to fulfil it. What looks at first glance like an ordinary US penny is actually an innovative storage medium that accommodates, among other things, 106 works of art from 30,000 years of human history on one thumb-sized metal disc: these range from cave paintings to masterpieces of the Renaissance, Romanticism and Art Nouveau to works by contemporary artists. Also immortalised on the “Memory Disc V3”, however, are paintings by children from a social project in San Francisco. As is the original French edition of “The Little Prince” by Antoine de Saint-Exupéry.

Fittingly, the pulsar map – humanity’s first attempt to give extraterrestrial civilizations an impression of our culture and show them how to find us – that was blasted into space with the Voyager probes in 1977 is also engraved on the storage medium.

Not only that, but 286 translations of UNESCO's guiding principle have also been preserved in perpetuity on the memory disc. “Since wars begin in the minds of women and men, it is in the minds of women and men that the defences of peace must be constructed” – this is what it says in the constitution of the United Nations agency founded in 1945, which is participating in the project. “It is languages that carry the knowledge, identity and worldviews of peoples,” says Tawfik Jelassi, UNESCO Deputy Director-General for Communication and Information. By participating in the initiative, UNESCO is seeking to ensure that no language or culture would fail to be included on the memory disc, he adds.

This coin-sized repository of all human memory is made of raw nickel, and there are good reasons for this. After all, this silvery metal is corrosion-resistant. So, it can’t rust and is intended to withstand cosmic extremes such as radiation, magnetic fields and extreme heat and cold and thus preserve the information recorded on it for millions of years out in the blackness of space.

The texts and images are being stored using NanoFiche technology, a laser engraving process with a resolution of 133,000 dpi (dots per inch). This enables the creation of structures of only 200 nanometres in size, about 420 times finer than a human hair. According to Barrelhand, 4.5 gigabytes of data will fit on the small metal disc in this way, as much as on a conventional DVD. But unlike a DVD, the memory disc cannot get scratched or burnt and does not need a special player for the stored information to be read. All that is needed is light and lenses – albeit particularly strong ones if you want to see the engraved works of art in all their detail.

Whether the process will deliver what it promises, the miniaturised texts will be legible and the microscopic masterpieces will do justice to the full-size originals is something the experts at ALTER | HTV have undertaken to scrutinise. This is an unusual task for the employees of the TÜV NORD GROUP subsidiary from Bensheim in southern Hesse, as their daily work is generally dedicated to the meticulous testing of electronic components.

First, the team led by physicist Christian Melzer used high-resolution optical microscopes to obtain a comprehensive overview of the entire contents of the memory disc before recording detailed views. “Since optical microscopes reach their limits over and above a certain level of detail, we also used scanning electron microscopy to precisely document particularly detailed or small objects,” explains Melzer.

Like photographers who visually capture bacteria, viruses or cell structures, the experts had to select their microscopes very carefully and adjust them with precision to allow them to capture the images and texts stored on the memory disc as well as possible. “We had to explore the limits of what could be done and work under conditions of extreme cleanliness to avoid surface contamination,” the physicist says. The expert’s final verdict was unambiguous: “The quality of the memory disc’s display is impressive; even the smallest objects in the micrometre range are depicted in great detail.”

At the end of 2025, the first Memory Disc V3 is scheduled to accompany astronauts on a mission to the moon to be conducted by US company Astrobotic Technology, during which it is to be dropped near the lunar South Pole. A second mission is planned for 2027. In this process, the memory disc will be built into the lunar rover of the space company Ispace and left behind in the Schrödinger crater.

For all its astonishing depth of detail, the memory disc still shows the masterpieces of art history only in monochrome instead of colour. But its development doesn’t have to stop there, says ALTER I HTV’s expert Mr. Melzer with conviction: “If we’re aiming to preserve the colour information of the image templates, partitioning the images into colour channels would appear to be a promising solution.” For example, future generations or extraterrestrial intelligences might still be able to admire the smile of the Mona Lisa or the iconic “Great Wave off Kanagawa” by the Japanese woodcut master Katsushika Hokusai in all their delicate colourfulness on the moon millions of years from now.