High Energy Emission Civilisations detected at long range in the Milky Way Galaxy to date
Within the archives of 12 Muuh colonies in the Pluton volume, several Muuh historifics mention a series of messages sent from the direction of the Scutum-Crux Arm/near NGC 368 of the Milky Way, which described a now-undetectable branch of Muuh civilization at the same (or higher) level of advancement and expansion as the Terragen sphere. The signals described in their historifics reached their (currently) Terragen-adjacent colonies between 14.85 and 14.7 million years ago, depending on which colony's records mention the messages. These dates correspond to an alleged collapse of the Muuh civilization from unknown reasons. Similar to the Triangulum Transmission, and Pas'utu'ril transmission, the messages reportedly described a civilization in detail - here with full megastructures, black hole brains, Muuh cybercosms with Muuh-like and very un-Muuh-like virtuals, Muuh colonies inhabiting planets with a wider range of temperatures, and varieties of the System of Response far more similar to 6th singularity archailects than the form known to Terragens. Several historifics described the message as a broadcast from the "Greater Muuh" civilization, with all colonies known to terragens as "lost Muuh colonies". Five other historifics of the signal consistently described the "greater" civilization as "bad, foolhardy, too loud, and too resource intensive" and the Terragen-proximate Muuh colonies as "safe" and "quiet", "pure".
However, none of the Muuh colonies' archive groups revealed their possession of these historifics of the signal until several centuries after Terragens had fully confirmed the existence of the HEEC1 civilization (which is located near the signal's supposed origin), and shared their full observational data with the Muuh, and the Muuh had shared general historical maps of the galaxy within their records in return, in diplomatic discussions between 8500-9100AT. Most of the content of the secondhand Muuh records surrounding the Scutum-Crux message were speculative recreations of the civilization - which matched observational data already shared with the Muuh by Terragens or which didn't match current astronomical observations. Any simulations of the historical positions of the stars in question have offered only ambiguous conclusions. In addition, the archives of these Muuh colonies used records systems with flexible/editable date stamps, and had been copied too many times for true authentication. Therefore, most Terragen xenohistorical institutes have concluded the true creation dates of these records (and all of the records of the signals and their content) might have been fabricated as an exciting speculative fiction story in response to what the Terragens (or possibly even an earlier civilization) had discovered.
The record closest to physically confirmable came from the secondhand source of a Muuh museum ship that had travelled from the same region as the Scutum-Crux signal. A preserved version, or recreation, of this Muuh museum ship had sat preserved in a tomb/library on the colony of Pluton Yarr for the past 3 million years at minimum, as far as Terragen exopaleontologists have been able to determine with any certainty. The preserved craft had held fifty variants of a historific in which an advanced Muuh-inhabited Dyson Swarm, or methanogenic planet, named World of the Nonlinear Crystals (depending on the story version) "fearfully left this universe/reality" by methods ranging from uploading into solipsist cybercosms around (observable) stars in the HEEC1 civilization to physically impossible methods like backwards/branching time travel. In these historifics, their reasons ranged from "because they wished to do so" or "the cybercosms seemed more interesting and sustainable" to "they wished to escape The Things Which Dwell in Time". Terragens have found no physical evidence to confirm any of these possibilities yet, beyond the record-keeping spacecraft itself.
Completely absent from the historifics of these signals, of course, was any information that clearly fell within the Muuh Taboo. Nothing resembling a known Muuh pylon exists in the records of the Scutum-Crux signals (or in any observational data of the real Scutum-Crux HEEC civilization, which likely contains mostly virtual civilizations and has little physical activity visible by telescope). Even if the HEEC1 civilization has existed for 14.8, or even 3 million years, any traces of the version described by the Muuh have likely been built over to the point of unrecognizability. The information in some of the historifics might approach (but does not actually directly address) the true location of the Muuh homeworld and the stability of the Muuh culture, both of which would fall within the Muuh Taboo. Whether the "Greater Muuh" civilization is supposed to be actually centered around their original homeworld or is simply an older cluster of Muuh colonies during an expansive period of their long history remains unclear and isn't mentioned in any of the historifics. Therefore, some researchers say this gives further evidence that the entire Scutum-Crux transmission records are completely speculative fictions rather than any kind of half-truth that could breach the Muuh Taboo. As usual, most Muuh institutions have excitedly confirmed all possibilities to be true, at different moments.
Several groups of Terragens in the Perseus region have attempted to create cybercosms and physical fan-recreations of smaller aspects of the "True Muuh" civilization from the secondhand historifics, using neogenic designs and public terraforming equipment/fabricators, in the centuries after learning of the Muuh's historifics about the signals. When they offered to share their recreations with any Muuh however, or allow visiting Muuh representatives to explore any physical fan-recreations of the historifics, the Muuh representatives showed reactions very different from their apparent interest when viewing the historifics as their own non-physical records. Muuh representatives declined, avoided traveling within at least hundreds of AU of the recreations, and cited reasons ranging from detailed but overall contradictory criticisms about the authenticity, to repeated phrases of "this is very unlucky/perverted". Large-scale fan recreations of the "Lost Muuh" myth have since been heavily discouraged or banned by Terragen authorities in the Muuh-adjacent areas, when possible using local laws and treaties. Outside of these regions, several NoCoZo or Cyberia-aligned polities (among others) have continued the fan recreations, though any invitations they have sent to Muuh representatives have remained utterly ignored.