Fourth Cataclysm of Mnomn
This Archivist 14 Datagram record was recovered from the private collection of an AI enthusiast during a bankruptcy auction resulting form the collapse of financial collapse their interstaller shipping concern. It is unknown how the collector came to posses it, and it is missing its headers and checksums. The anthropological information within is consistent with related publications by Archivist 14's contemporaries, but the exact content may have been tampered with and is considered suspect for the purpose of studying the Archivist itself.
Historians generally mark the beginning of the 4th Cataclysm of Mnomn as the Mnomn date 22.63.22, the day that the Outworlds League launched the atomic weapons that ultimately led to the permanent changes in the Mnomn planetary climate that are most commonly associated with the 4th Cataclysm. The end date of the Cataclysm is much less concrete. The last live transmission from any Outworld League by a live operator was sent on Mnomn date 22.64.98, nearly 50 terran years later. Another 10 terran years after that, survivors on Mnomn reestablished control of their orbital communications satellites and in so doing, climbed above the Egoathropological Limit for the purposes of external study.
The Mnomn after their third Cataclysm were an Hermaphroditic species, with an atomic powered space faring culture. They had established resource extracting colonies on a dozen planetoids in their home solar system, and they had even begun to detect and decipher broadcasts from the sentients of Purnisc some 15 light years distant, though they lacked the means to send any individuals to Purnisc, they did launch 3 unmanned probes in an attempt to establish communications with the species there.
Offworld colonists were initially regarded as great heroes of the Mnomn people, laboring in dangerous conditions and deferring their breeding rights so that all Mnomn on the homeworld could live more comfortable and more sustainable lives. However over time conditions changed - the high energy cost of rotating a Mnom colonist home and sending a new colonist out of the Gravity well led to longer assignments in space. In the Mnomn 22.62, a measure passed the planetary assembly to restore breeding rights to the colonists in exchange for making their colony postings permanent. This had widespread support from both the colonies and the homeworld at the time, but the devil, as they say, is in the details. The measure mandated that the homeworld would provide necessary support and supplies for turning the colonies into permanent and self sustaining settlements, but the language was not specific and negotiations between the two sides broke down. When a motion to repeal the measure was rejected by the assembly, the Outworlds League decided they had no choice but to respond with force, and they launched a salvo of hydrogen fusion bombs on 22.63.22, on a 60 cycle transfer orbit to the home world.
The 4th Cataclysm
It was always the case that the Offworld League was reliant on the homeworld for its existence, but that the homeworld would spin on, albeit less comfortably, in the absence of the colonies. The Offworld League's attack changed that calculus dramatically for a period of 60 cycles. Without active intervention by the League to disarm the warheads, the homeworld would be forever changed. This, they reasoned, would create a level playing field for negotiation of the conditions under which the colonies would become self sufficient. Assemblypersons, many of whom had already been working in good faith to complete the terms of the settlement measure, redoubled their efforts. But on 22.63.52, reactionary elements within the homeworld military staged a coup and disbanded the assembly. The cabal of generals who took command of the government took a hard line stance on the aggressive act by the colonists, cancelling all offworld resupply launches and confident that planetary defense assets would be able to intercept the missiles. This course doomed the colonists for certain, and ultimately led to the catastrophic collapse of Mnomn society on the homeworld as well. Of the 42 devices that were launched by the Offworld League, 13 struck the surface - 9 of these detonated as designed, destroying entire municipalities and throwing radioactive debris high into the atmosphere.
The offworld colonies, now cut off from their homeworld and support structure, and having received none or only a fraction of the materials necessary for truly sustainable self sufficiency, continued to communicate among themselves for many cycles - roughly 50 Terran years. Some of the smaller colonies ran out of supplies necessary for survival, but most of the colonists lived out their lives unable to breed and so the colonies died of old age.
On Mnomn, societal and environmental collapse walked hand in hand around the globe. Fallout thickened the atmosphere and made global communication impossible, leaving the remnants of the central government unable to exercise its will outside of its seat of power. Local tribe-like power structures rose up in most areas where significant survivors dwelt, and these clans remain the dominant governing force on Mnomn today. Though radiation blanketed the world for many years, female-stage Mnomn were largely resistant to its effects, so infrastructure and technology were maintained locally, even though global communications and logistics were encumbered to the point of impracticality. As the atmosphere cleared over the course of 6 Terran decades, groups reconnected to one another, the clans established mutually beneficial partnerships, and the Mnomn culture gradually reformed itself to meet the challenges of its new environment.
On 22.65.01, a group of technicians restoring a satellite up-link in the former planetary capital gained access to the geostationary communication satellite network that had been established prior to the cataclysm. It would be many more cycles before additional ground stations came online and restored communications worldwide, but this is generally regarded as the beginning of the end of the Cataclysm.
Aftermath and Impact
Prior to the cataclysm, the Mnomn were observed to freely change sexes throughout their lives, as social whims and mating decisions required. The transition from one sex to the other is a voluntary process, which begins with the rapid atrophy of the individual's current sex organs and then an additional pubescence. Through most of the transition, which takes roughly two terran years, the individual is biologically a juvenile - unable to bear children or impregnate others.
During the cataclysm, Male Mnomn died en masse from the radiation, while Females were largely unaffected. In many species, this would have been an extinction level crisis, but for the Mnomn it merely upended their societal sexual fluidity. The ambient radiation even after the initial event meant that once a Mnomn became Male and fathered a child or children, they typically succumbed to the radiation before they could transition back to Female and restore their previous immunity. In the wake of the cataclysm, becoming male and breeding became heavily controlled and centrally managed by clan leaders and eventually a council of clans. Though the radiation risk for Males is growing lesser over time, clans remain very dominant in arranging breeding unions.
When the Mnomn finally reasserted themselves to the point of accessing their long dormant communications satellite network, they found and deciphered a reply to their initial probes to Purnisc. Suddenly becoming aware of their not being alone in the cosmos led the Mnomn to a renaissance of creative culture and philosophy consistent with the Emergence Theory of First Contact, although to this day the Mnomn have not reached a level of technological maturity necessary for interstellar travel.