The Archivists are an extinct alien species known only from their data storage artifacts. Two classes of these Archives have been discovered. All examples of each class appear to be physically identical. A Lesser Archive is a sphere approximately 1.2m in diameter. An outer diamondoid shell surrounds a layer of machine-phase material, within which lie further shells of crystal-linked magmatter components which in turn enclose a quantum-density information storage system. The operating principles of this quantum-density memory remain unexplained. The diamondoid outer shell is punctured by ports used to read and write the memory contents by means of bursts of coherent gamma rays. The whole system masses ten thousand tons, most of which is the mass of the central core. The Greater Archives are generally similar but are approximately 1.6m in diameter.
The first Lesser Archive to be discovered was found in 4666 a.t., orbiting the brown dwarf Niflheim in the GIA 348-5443344. The finder was a refugee ship fleeing the Negentropy Alliance's destruction of the Sagittarius Sphere's settlements in the Canakka system. In the course of the next century, the civilization established by the refugees made several failed attempts to extract data from the device. Three centuries later the Archive was destroyed during the last stages of the Ideoclastic Heresy. The energy liberated by the detonation of the device boiled the atmosphere of Midgard into space and totally sterilized that world. Shortly thereafter the asteroid habitats succumbed to ecological instabilities and Terragens became extinct in the system. Since that first find, several dozen Lesser Archives and three more Greater Archives have been found in systems across the Aquila Expanse and in the Coreward parts of the Sagittarius Arm. It is estimated that there may be as many as a billion Archives still awaiting discovery. The majority of the known Archives are in orbit around stable brown dwarfs and gas giants, although it is believed there are many more undiscovered examples orbiting stars as far out as the Oort cloud. Possibly there could be freely drifting archives in interstellar space, although the chance of finding them remains minuscule.
The diamondoid outer layer shows a consistent pitting due to micrometeorites that gives a date of 1,452 (+/- 5) million years for its manufacture. As far as can be determined, the informational content of each Lesser Archive and each Greater Archive is identical, although the overwhelming quantity of data stored in each precludes a full comparison. Clearly the data must have been of great importance to the Archivists for them to store them in such a massively redundant manner, but it appears to be compressed to the entropic limit and no progress has been made towards deciphering their contents. Furthermore, no other relics that are unambiguously related to the Archivists have been found.