Level 1 — Absolute Beginner

Long ago, people in Turkey wrote letters on clay. This was about 4,000 years ago. They lived in a place called Kanesh. They wrote with a special writing called cuneiform.

People put the clay letters inside clay envelopes. The envelope kept the letter safe. But nobody could read the letter without breaking the envelope. Breaking it can destroy important marks on the outside too.

Now scientists have a new tool. It is a scanner that uses X-rays. The scanner can see inside the clay envelope. It does not break the envelope. Scientists can read old letters for the first time.

One letter was from a woman named Anna-anna. She wrote to her husband, Ennum-Ashur. She wanted to get silver that a man owed her family. Now we can read her words after 4,000 years.

cuneiform

A very old kind of writing made with small wedge shaped marks.

archaeologist

A person who studies old things left by people long ago.

envelope

A cover, here made of clay, that protects a letter inside it.

seal

A special mark pressed into clay to show who sent something.

scan

To use a machine to look inside something without opening it.

ancient

Very, very old, from a long time ago.

merchant

A person who buys and sells goods for a living.

non-destructive

A way of studying something that does not break or damage it.

Level 2 — Elementary

About 4,000 years ago, Assyrian merchants lived and traded at Kanesh, a Bronze Age trading colony at modern day Kultepe in central Turkey. They wrote business and personal letters in cuneiform, pressing wedge shaped marks into soft clay tablets. Many of these tablets were then sealed inside clay envelopes stamped with cylinder seals, almost like an ancient version of a sealed letter in a locked box.

Until now, the only way to read a sealed letter was to physically break its clay envelope. That destroyed the outer layer forever, along with the seal impressions and address details stamped on it. Archaeologists faced a hard choice: open the letter and lose information, or leave it sealed and never read the message inside.

Researchers have now built a non-destructive scanning tool, described in the journal npj Heritage Science, that uses a mobile X-ray computed tomography, or CT, scanner to look through the clay envelope without opening it. The scanner creates a detailed 3D model in minutes, letting researchers digitally unwrap the tablet and read the hidden writing on a screen instead of with a hammer.

The team brought the scanner to the Museum of Anatolian Civilizations in Ankara for about three weeks starting in mid-September 2024. There, they scanned 64 tomograms of 48 sealed tablets and other objects, including a very personal letter that a woman named Anna-anna sent to her husband, Ennum-Ashur, nearly 3,800 years ago.

tablet

A flat piece of clay used for writing in ancient times.

cylinder seal

A small carved stone cylinder rolled onto clay to leave a personal mark.

tomography

A scanning method that builds a 3D picture from many X-ray images.

excavate

To carefully dig up buried objects for study.

colony

A settlement of people living away from their home city, often for trade.

debtor

A person who owes money to someone else.

digitally

Using a computer, rather than by physical or hands on means.

preserve

To keep something safe from damage or destruction.

Level 3 — Intermediate

Roughly 4,000 years ago, during the Old Assyrian trading colony period, from about 1950 to 1836 BC, Assyrian merchants operating out of Kanesh, a Bronze Age settlement at modern day Kultepe in Kayseri Province, central Turkey, conducted business across long distances using cuneiform, the world's first writing system. Scribes pressed wedge shaped signs into soft clay tablets recording contracts, debts, and family news, then frequently enclosed the tablets inside clay envelopes stamped with cylinder seals, a practice that authenticated the sender and protected the message in transit.

For as long as these sealed letters have been studied, reading one has meant destroying it. Breaking open a clay envelope permanently eliminates the outer layer, along with the seal impressions and any addressing information it carried, information that is itself valuable evidence about who sent a letter and to whom. This created an unavoidable trade off between preserving physical evidence and recovering the written content sealed within.

A team of researchers has resolved that trade off with a newly developed, non-destructive scanning method, published in the journal npj Heritage Science. Using a mobile X-ray computed tomography scanner, the system images a sealed tablet in a matter of minutes, generating a high resolution 3D model from which researchers can digitally separate the outer envelope from the inner tablet and read its cuneiform text without ever touching a chisel to the clay.

Deployed to the Museum of Anatolian Civilizations in Ankara for roughly three weeks beginning in mid-September 2024, the scanner produced 64 tomograms across 48 sealed tablets and related objects. Among the letters brought back to legibility was one written nearly 3,800 years ago by a woman named Anna-anna to her husband, Ennum-Ashur, who was away on business. Its exterior, marked only by her seal and his name, gave no indication of the very personal financial dispute recorded inside.

authenticate

To confirm that something is genuine or truly from the stated source.

legibility

The quality of being clear enough to read.

resolution

The level of fine detail visible in an image or scan.

trade off

A balance between two things that cannot both be fully achieved at once.

authenticity

The quality of being real, genuine, or trustworthy.

deployed

Put into use or position for a particular task.

correspondence

Letters exchanged between people, or the act of exchanging them.

scribe

A person trained to write or copy documents by hand.

Level 4 — Advanced

For nearly two centuries of Assyriological scholarship, one obstacle has stubbornly resisted every advance in imaging technology: the sealed clay envelope. At Kanesh, the Bronze Age trading colony now identified with Kultepe in Kayseri Province, central Turkey, Assyrian merchants of the Old Assyrian trading period, roughly 1950 to 1836 BC, conducted an extensive long distance commerce whose paper trail survives in cuneiform, the world's oldest attested writing system. Correspondence and contracts inscribed on clay tablets were routinely enclosed in outer clay envelopes bearing cylinder seal impressions, a mechanism that simultaneously authenticated the sender and rendered the enclosed text physically inaccessible without destruction.

That inaccessibility has long forced an uncomfortable choice on excavators: crack open the envelope and recover the letter while permanently erasing the sealing evidence and address information stamped on its exterior, or leave the object intact and forever forgo its contents. A newly published methodology, detailed in the journal npj Heritage Science, dissolves this dilemma. By deploying a mobile X-ray computed tomography scanner directly to the artifacts rather than transporting them to a fixed facility, researchers can generate a high resolution volumetric scan of a sealed tablet within minutes, then computationally disentangle the envelope's geometry from the inner tablet's to render its cuneiform text legible on screen, with the physical object never touched by a blade.

The instrument's first sustained field deployment, at the Museum of Anatolian Civilizations in Ankara for approximately three weeks beginning in mid-September 2024, yielded 64 tomographic scans across 48 sealed tablets and associated objects, a throughput that would have been unthinkable under destructive methods applied to irreplaceable artifacts. Among the correspondence thereby recovered is a letter composed nearly 3,800 years ago by a woman named Anna-anna and addressed to her husband, Ennum-Ashur, then absent on commercial business, its envelope betraying nothing beyond her seal impression and his name.

What the digital unsealing exposed was neither a formal contract nor a ceremonial message but an intimate domestic grievance: Anna-anna had been attempting to collect silver owed to her husband, only to be rebuffed by a debtor who insisted he would settle the debt with no one but Ennum-Ashur himself, upon his return. Excavated originally at Kultepe and held for years afterward at the Museum of Anatolian Civilizations, her letter joins more than 20,000 cuneiform tablets recovered from the site, a corpus, written in Akkadian, that constitutes one of the richest surviving archives of daily commercial and family life from the ancient Near East, and one whose sealed portion has only now become fully legible.

volumetric

Relating to a three dimensional measurement of space or volume.

disentangle

To separate something complicated or tangled into its distinct parts.