The Old Terraformers were a frustratingly tidy people – unfortunate from an archeological perspective, but natural in a culture deeply concerned with ecology and long-term planning. They left no middens or landfills for excavation. Also, they apparently left the Reach deliberately, in an orderly manner, and took almost all their valuables with them, including all their cities, in entirety.
Old Terraformer remains are almost wholly technical in nature, and are grouped under the headings of "psitech" (psionic traces), "epigraphy" (writing samples), and according to size.
Nanotech remains are microscopic or nearly so. They are numerically the commonest and, in many ways, the most informative, but they do not have much hold on the popular mind – rather like potsherds and accountancy tablets in conventional archeology.
Most nanotech artifacts ("nanofacts") are found in soils, muds, oozes, and other sedimentary settings. Many are found inside grains of sand. Some appear to be intended for use inside cyborganized microbes. Their uses, in varying degrees of conjecture, include:
60% of nanofacts are of unknown function.
Mesotech remains are in the size range of hand-held objects and individual buildings. There are frustratingly few of them.
Most of the surviving buildings and chambers come from the remains of space stations. Based on these, the Old Terraformers seem to have varied in appearance and were probably multi-specific. Many chambers and doorways were large, but had handles and other controls, where they survive, generally near the floor. This suggests accomodation to large and small beings simultaneously. Other chambers seem to accomodate only one of several different sizes of creature.
Most surviving hand-held objects are minor pieces of metal or polymer hardware or scraps of stationery, all preserved in vacuum, either in the ruins of space stations or in lunar caverns. (See Macrotech.) The hardware – fasteners, boxes, bits of sheeting, minor struts, occasional tools – give the same impression as the buildings and chambers. Old Terraformers came in several sizes. Most probably had hands or claws rather than, say, tentacles.
The stationery is mostly a permanent aeromer resembling paper, expensive in terms of current Reach technology, but evidently trivial for the Old Terraformers. It forms the basis of what little we know of Old Terraformer language. See Epigraphy.
There are two forms of Old Terraformer epigraphy – mainstream and fringe. We will discuss the mainstream first.
Old Terraformer writing appears mostly in preserved stationery, but also on boxes and occasional walls. It is probably all one script. Careful study has produced a character set, including numerals in base 16. These numerals, taken from page numbers, are the only bits of Old Terraformer language that can be read with confidence. Beyond that, we can only say that the script is alphabetic and uses between 30 and 45 letters, depending on which characters are letters and which are punctuation, and which are typographical variations of others. There are tentative theories about the meanings of some words (or, more exactly, character strings), based on such clues as frequency and placement.
Full translations always come from the fringe of Old Terraformer archeology, and many claim to depend on psychic probing. The best-known of these is Inasis Bevvasi's Primal Annalects, which presents a pantheistic, reincarnational religious view, in which the Old Terraformers are authors of all sapient life in the galaxy, including humans, and collectively ascended to a Higher Plane, whence they oversee our spiritual development.
Old Terraformer script is composed of disconnected dots, curves, and short strokes, making it easy for fringe epigraphers to "discover" inscriptions on rock faces and "genetically coded" in the markings of plants and animals. Crab carapaces are a rich source of such "genetic epigraphy."
There are also some undoubted inscriptions in Old-Terraformer-like script, but most of these are no more than a few centuries old and are examples of punctiliar lettering. (Punctiliar lettering is a style developed by the Old Settlers of Hebara, in conscious immitation of Old Terraformer script. However, it is actually an exotic form of the Roman alphabet. Punctiliar inscriptions are almost always in any of various early dialects of Terranic.) Fringe epigraphers acknowledge this, but claim there are exceptions that are genuine Old Terraformer.
Psitech remains are psionic traces. The clearest are found in the remains of Old Terraformer cities, where they are evidently remnants of energy transfer and structural support systems. The largest is a massive levitation trace at an otherwise empty Lagrange point opposite the gas giant Lempi 1, apparently an anchor for a space station city.
Other psionic traces have been found here and there, but they are too much eroded by natural icon turnover to be confidently identified. At least by mainstream archeology.
Fringe archeology has, of course, had a field day with smudgey Old Terraformer psi traces, and with psi traces that are not clearly traces at all. Many and various visions derive from these, the commonest being images of alien cities evaporating like mist into Higher Realms; solemn assemblies of tall, thin humanoids in robes of black, white, and green; and surrealistic visions of "hyperspace."
Macrotech remains are city-sized. In fact, they are usually the empty sockets where Old Terraformer cities once stood. Most of these are wide, shallow, irregular craters, relatively pristine on non-tectonic worlds, often heavily erroded on tectonically active worlds.
There are also giant caverns on moon-like worlds with negligible or useless atmosphere. Since such worlds are usually non-tectonic, most of these caverns are in pristine condition. They appear to have been produced by shaped explosions, walled with fused and compressed stone, laced with an irregular reinforcing mesh of macrometal, primarily aluminum. In many cases, these lunar caverns have no openings. Access must have been by some form of teleportation.
The most interesting city ruins are the abandonned frames of space stations. Only four of these have been discovered; the Old Terraformers probably took their other space stations whole. The few buildings and chambers attached to these frames give us our only clues about the physical appearance of the Old Terraformers. See Mesotech.
These frames are made of macrometal – mostly macro-aluminum and macro-steels – and sophisticated metal-polymer composites. None of these are beyond the technical grasp of Reach humans, but it is instructive that these are the sort of materials the Old Terraformers felt free to discard, their equivalent of old bricks and mortar.
Geotech remains are large-scale alterations in the geographies of planets, and are part and parcel of the terraforming activity of the Old Terraformers.
The most famous example is the Grand Canal, irrigating the subsolar continent of Impri. Many Mars-like worlds are irrigated by systems of canals. Some worlds with thin atmosphere have systems of very deep canyons cut into them, for the sake of the higher air-pressure at the bottom. Some moon-like worlds have extensive systems of interconnected caverns, an expansion on the concept of the cavern city listed under Macrotech.
Geotech also includes the placement of minor, asteroidal moons, usually as foundations for space stations.
The reality of Astrotech is controversial. Believers in Astrotech hold that the Old Terraformers altered the orbits and rotations of some worlds to enhance their viability.
Some even claim the Old Terraformers moved stars within multiple star systems, or moved whole star systems. They point to geometrical regularities and "unlikely" orbital resonnances in the star charts of the Reach, but mainstream science sees the same amount of regularity and "coordination" in the stars beyond the Reach and in randomly generated simulations.