Twin planets in Musca - originally called Helen and Clytemnestra

Image from Steve Bowers
These worlds are similar in size and mass, but have quite different topographic features

Neli-Neti Data Panel

StarHIP 63911
Stellar classF5V
Luminosity3.09 x Sol
Distance from Sol698 ly

Neli-Neti binary planet system

TypeDioscuran-Gaian pair
Mutual Separation197990km
Mutual Orbital periodday length (tidally locked) 7.14 standard days
Semimajor Axis around HIP 63911- 1.822 AU
Year Length2.09 standard years
Colonised3189 AT

Neli (originally Helen)

Diameter13020 km
Surface Gravity1.04 gees
Density1.014 x Earth
TypeEugaian (65% water cover)

Neti (originally Clytemnestra)

Diameter12590 km
Surface Gravity0.98 gees
Density0.99 x Earth
TypeLacustric Gaian (48% water cover)


Diameter9802 km
Semimajor Axis3.1 AU

After the battle for the garden world Darwin in the Delta Pavonis system, some of the displaced colonists found new homes on Mendel and the other worlds and moons of this system, while others swelled the numbers of inhabitants in space habitats orbiting those worlds and constructed new ones for themselves. Others ventured farther afield; a large contingent moved to Little Garcia in the Epsilon Eridani system, and by the Age of Expansion some were looking at more distant destinations among those stars which were targets for the new wave of fast colony ships.

The Musca Sector Long Range Project launched a mission towards HIP 63911 in 2205 AT. A pair of twin Earth-like worlds in this system were an intriguing target for colonisation. A conversion drive ship capable of attaining 70 percent of light speed was made available by the S:2 transapients who were in overall charge of the Project corporation. On board were twenty-five thousand modosophont colonists in nanostasis, and a First Singularity transapient in a largely inactive state.

On arrival in 3189 AT the Project colonists surveyed the twin worlds, and voted to give them names from classical antiquity; Helen and Clytemnestra, the legendary female twin sisters of Castor and Pollux. Helen, the largest planet, is somewhat wetter than the smaller Clytemnestra, which has low relief and is mostly covered in small lakes as opposed to Helen's larger seas and oceans. Neither planet had indigenous life, and both had a typical lifeless Gaian atmosphere of nitrogen, carbon dioxide, water vapour, hydrogen sulphide and a little neon.

The accompanying transapient, who called emself Rudra, assisted with the terraformation of Helen, while concentrating on establishing Clytemnestra as a new home for translocated species from the Darwin xenoecology. The process of terraformation was fairly straightforward on both worlds, as both had ample reserves of nitrogen and water; oxygen could be manufactured from carbon dioxide and water using gengineered photosynthesisers, while the sulphides were scrubbed and sequestered along with excess carbon. During this process, which was expected to take about two hundred years, the colonists lived in environmentally sealed habitats on the surface of Helen, growing crops in low world houses and gradually increasing in number.

Shortly before Clytemnestra was fully terraformed, a faction of colonists led by Ede Yadav petitioned Rudra to release the world for human colonisation, as they wished to form a breakaway colony there. The idealistic Yadavists wanted to establish a moneyless economy based on a system known as UPR, Uncapped Personal Resources, whereas the ruling parties in most of the domehabs of Helen were committed to a money-based economy. While the colony was still in a fast-developing state the economy was in a state of growth, and most colonists were able to find remunerative employement of various kinds; but Ede Yadav looked forward to a time when these worlds would reach a state of post-scarcity, making a money- or credit- based economy irrelevant.

Image from Steve Bowers
Helen has large seas and oceans, with active plate tectonics forming continents.

To Yadav's surprise the transapient Rudra immediately agreed to her request; the world Clytemnestra would become a second terraformed home for nearbaseline humans, while the translocated Darwinian species would now be housed on a third planet, the Arean world Cassandra further out from the local star. Some transapientologists have suggested that this may have been Rudra's plan all along; certainly the more distant planet would be relatively free from cross-contamination by terran microbiota, unlike the twin planet Clytemnestra. A few decades of additional work by terraformation swarms brought this world to full human habitability, although the long natural day/night cycle of both Helen and her twin (more than seven times as long as Earth's) required constant redistribution of heat and sunlight by airborne Class 2 Weather Machines.

When Helen and Clytemnestra were both fully habitable in 3998 AT, Rudra withdrew to Cassandra to pursue eir own projects, leaving the nearbaselines to establish their own cultures without further interference.

The Yadavists on Clytemnestra

Faced with an empty planet nearly as large as Earth, the Yadavists (who numbered less than ten thousand persons) had much to occupy their time. Their first priority was to construct a very large number of subsentient robot workers of many shapes and scales, from innumerable microbots and synsects to manage the developing ecosphere to the vast earth-moving equipment required to reshape the hydrology and landscape of this formerly lifeless planet. Most of the recipes for these robotic workers were open-source and freeware designs gathered from the databanks of many worlds, some of which were better than others. Controlling these vast armies of automatons required constant effort on behalf of the human colonists, who were slowly increasing in number and establishing new towns and cities on the vacant continents.

In a relatively short time their money-less economy was deemed to be a success, particularly since they had the entire resources of a planet to play with. This success was assured when Yadav ascended successfully to S:1 transapient status in 4213 AT, and assumed control over the finer details of the economy.

One problem was the difficulties of trade between the twin worlds, since the Hellenite economy was based firmly on credit and money at that time. A certain limited bartering system was established between the two systems, but many of the Hellenite corporations were reluctant to deal with the breakaway state.

Image from Steve Bowers
Clytemnestra has 48% water cover, and tectonic activity is subdued so no large continents exist in the current era.

Version War - The Battle of Cassandra

A Negentropist Battle Group consisting of the battlecruiser Logical Priors and the battleships Reasonable Damage and Necessary Misfortune entered the system in 4470 AT and attacked the transapient hyperstructures surrounding the xenoecology reserve on Cassandra. The Priors was almost immediately disabled, then destroyed by godfire, and the other two ships were hounded out of the system by Hellenite and Clytemnestran destroyers.

For the rest of the war the HIP 63911 system was free from conflict, but Parthene refugees from the nearby system of Atwood began to arrive in 4501 AT, and established separate colonies in orbit around the twin planets. Habs Helen I,II,III,IV and Clytemnestra I/II soon became thriving centres of the all-female Parthene culture.

The Emergence of Jensanism

After the War, the female clone societies in the orbiting habitats differentiated into a number of very different cultures, including a strict hierarchical matriarchy led by Vosia Jensan XI in hab Helen IV. Parthene females usually give birth to their own clones except where artificial hybridisation occurs. The hierarchy in this particular hab was arranged strictly by bloodline, with certain clone-groups assigned high hereditary offices.

Vos5 Jensan, herself a pure-blood clone of Jensan XI and destined for high office, rebelled against this elitist society and established a quasi-religious communist movement, distinguished by uninhibited public festivals. This sect, known as Jensanism, quickly became popular in the habs, and threatened to destabilise the cultures not only in Helen IV but in all of the skyhabs. Jensan XI and the other habitat leaders acted to repress the unruly rebellion, and in due course were successful; in 5005 AT the leaders, including Vos5 herself, escaped in a passing Spacefarer Union craft to JD 1904456593, where they founded a new colony.

The Transapient Hypereconomy

In the ComEmp era Helen was host to a flourishing modosophont economy based on a free market; efficient use of resources meant that most commodities were very cheap, but even small amounts of value could be exchanged efficiently using ubiquitous information technology. Inequalities of wealth that sometimes emerged in this economy were reduced by a tradition of sponsorship for a wide range of cultural and recreational activities. In 5400 AT Helen joined the NoCoZo.

Fierce competition at the top of the business community led to a number of transcensions; several superbright chief executives and superturing marketminds became transapients in this era, leading to the establishment of a hypereconomy that relegated the modosophont version to a subsidiary role. The rapidly changing economic landscape bewildered some but was a welcome challenge to others.

The Yadavists on Clytemnestra on the other hand maintained a non-monetary system known as Uncapped Personal Resources; all commodities were nominally cost-free, but the citizens of this world were mostly content with relatively modest levels of consumption. Since the early days of the colony the economy on this world had been subtly managed by the S:1 entity Yadav who seems to have encouraged this modesty. Clytemnestra joined the Utopia Sphere, as an outlier world, in 5541 AT.

Sometimes the citizen zars of this world desired to access resources on a grander scale than usual, and ambitious construction projects were conceived; new patterns of islands and lakes were formed on the surface of this motley world, or resource-hungry exploration projects were launched. But most of the time this world maintained a conservative and conservationist approach to consumption, sometimes observing the frenetic pace of change on the sister planet with a certain amount of disdain.

Yadav Ascends

In 6866 AT Yadav ascended to S:2, and left the Twin Worlds to join Rudra in orbit around Cassandra, where the imported xenoecology from Darwin was evolving at an intriguing rate. The moneyless economy of Clytemnestra continued to function well for some centuries afterwards, but by 7000 AT instabilities were becoming apparent, and a Hellenite transap known as Achelous stepped in to bring it back on track.

Soon Achelous had assumed the same sort of control as Yadav had once exercised. Many of the inhabitants of Helen (now known as Neli in the local language) regarded the denizens of their sister world (which had become known as Neti due to linguistic drift) as charity cases, unable to look after themselves. The people of Neti thought of their neighbours as frenzied propertarians, obsessed with novelty and acquisition.

Transapient Withdrawal

Achelous gradually engineered modosophont society on Neti to become more self-sufficient and stable, and after several centuries e seems to have been satisfied with the result; the transapient withdrew from this world in 7312 AT, and rejoined the company of eir peers on Neli briefly, before following Yadav and Rudra to Cassandra. During the Central Alliance period several more transapients left Neli to migrate to this world, where a new species of provolved Paraeurypterid was being developed. This species, known as the Paraz, had started to develop a new and intriguing culture that seemed to fascinate and attract the local transapients. By 7777 AT no transapients were permanently based on either Neli or Neti.

Rule of the Modos

For more than a thousand years the sub-transingularity inhabitants of the twin worlds continued to thrive, in their very different ways; the departing transapients had engineered the economies of these worlds into stable and robust forms. The capitalist libertarians of Neli were amused by the antics of the communist libertarians of Neti and vice versa, but both societies were essentially rationalist materialist in outlook. These was a healthy exchange of population between the two worlds, as various citizens decided to take advantage of the dynamic Non-Coercive society or the more laid-back culture of the Utopian world.

However, in due course this balance of opposites was disturbed by outside forces; the Parthenes in the orbiting habitats had long ago become integrated into the planetary societies, but a gradual influx of returning Jensanists began to establish a new and destabilising influence. Jensanism had developed into a cult with a strong hedonistic imperative, where sobriety was seen as anathema - in direct opposition to the hardworking ethos on Neli and the modest lifestyle of Neti. Jensanism became particularly entrenched in the island continent of Hermione, and the rest of Neli society was scandalised and affronted. Sanctions were imposed, leading to a certain amount of hardship - a situation unknown on these worlds for millennia, and one which led to disagreements and eventually open conflict between the worlds of Neli and Neti.

In their propaganda, the people of Neti called the society of Neli 'elitist', while the Neli accused their opponents of 'basking in mediocrity'. The forces of these two planets met in a war that was mostly fought among the lakes and low hills of Clytemnestra. But these two worlds were tied too closely together and too diverse to maintain such simple sectarian divisions for very long.

With some difficulty a peace accord was eventually reached. However this brief peace was broken by an even more damaging war in Hermione between Jensanists and NoCoZo mercenaries, often drawing the Yadavist peacekeepers into the conflict as well. This conflict was terminated abruptly in 9545 AT when a force of Paraz provolves invaded the twin planets, equipped with Sephirotic godtech weapons, completely overwhelming all other combatants with little or no bloodshed.

The New Synergy

Neli/Neti today is a completely new and transformed society, including elements of the old Yadavist and Helenite culture as well as Jensanist hedonism and a large pinch of Paraz exotica.

The Paraz reproductive strategy is r-selective, so that (in their unprovolved state) they have many offspring but few survive. Hi-tech Paraz allow many more of their offspring to survive, but in modified form as servants or specialised agents performing tasks usually relegated to automation in human-based societies. These specialised agents often become highly competent biobots and biological brains.

The Synergy is currently embarking on a program of colonisation, expanding into the Carina volume to join the (often equally exotic) cultures that are emerging there. Part of the Carina Rush.


2205 AT - Colonisation fleet leaves Darwin
3189 AT - Fleet reaches Helen and Clytemnestra
3207 AT - Yadavists petition for separate colony on Clytemnestra
3300 AT - Rudra begins the Darwinisation of Cassandra
3998 AT - Helen and Clytemnestra declared habitable
4213 AT - Yadav ascends to S:1
4470 AT - Negentropist warships attack outer system, are repulsed
4501 AT - Parthene refugee colonies I, II, III, IV established in orbit around Helen and Clytemnestra
4640 AT - Vosia Jensan XI becomes matriarch of Helen IV
4790 AT - Vos5 Jensan founds Jensanism
5005 AT - Jensanists escape
5309 AT - Jensan colonised
5400 AT - NoCoZo hypereconomy established on Helen
5541 AT - Clytemnestra joins Utopia Sphere
6866 AT - Yadav ascends and translocates to Cassandra
7000 AT - Helen and Clytemnestra become Neli and Neti
7312 AT - Achelous abandons Neti
7400 AT - Paraz provolves on Cassandra become fully sophont
7777 AT - Last transap leaves Neli; Rule of the Modos on Neli and Neti
8889 AT - Hermione taken over by Jensanists
9109 AT - Neli/Neti war on Neti
9512 AT - War on Neli against Hermione
9545 AT - Paraz forces re-establish order
10199 AT - The New Synergy starts to send out colony ships to the Periphery
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Development Notes
Text by Steve Bowers
Initially published on 28 May 2014.