100th Millennium Wiki
100th Millennium Wiki


Jivario is a terrestrial planet in the Criuden system, in the Flower Galaxy, located around 2,200 light years from Aziel. It was one of the first habitable planets to be settled on in the galaxy, and as a result Jivario is an important planet in the Yslov Federation with a very large population. It is a partial ecumenopolis, with many parts of Jivario completely covered in sprawling cities.


Jivario is relatively small a habitable planet, being around 10,600 km in diameter. Its mass is also similarly low. Unlike many inhabited worlds, Jivario does not have much native life, instead having mainly imported life from Humans arriving here. Aside from this, and the smaller scales, Jivario is very much habitable. Its system is more oxygen-rich than normal, and as a result Jivario has more tectonic activity and a stronger magnetic field than what would be expected of a planet this size, nearly 4 billion years old.


Jivario's atmosphere is slightly different from other atmospheres. It has a significantly lower percentage of nitrogen, and a higher percentage of water vapour and argon, a noble gas. These gases are not toxic to humans, and so most of them are able to breathe normally. As a result of Jivario's smaller mass, its atmosphere is thin.


Jivario is the second planet orbiting the K9V star Criuden. It is only the second planet, but it orbits quite close in at less than 0.46 AU from Criuden. Criuden's small mass, though, makes Jivario's year over 158 days long. The eccentricity and inclination of the orbit are negligible. Surprisingly, Jivario is not tidally locked, as its two moons keep its rotational period stable.

Major Moons


Ardehas is the most massive of Jivario's moons. Orbiting at around 150,000 km from Jivario, Ardehas is a dead rocky moon around 2000 km across, with no tectonic activity whatsoever. Although this, it does have many resources, such as water at the poles and many rare metals all across the moon. Many mining expeditions have been sent to Ardehas, and 1.4 billion sophonts currently reside on Jivario.


Svolun is the smaller major moon of Jivario. In a 5:2 resonance with Ardehas, Svolun is much smaller than it at around 900 km across, but it is more interesting than its bigger sibling. Svolun has a strangely high density, at around 5 grams/cm^3. This was more like Jivario's density, but for such a small body, it was strange. The most likely explanation is that Svolun was much bigger in the past, but a cataclysmic explosion (Similar to the one encountered by Jivario around 3 billion years ago) reduced it to its current size. Much of the mantle was ripped off, exposing the core, which is what Svolun is now. A bare core, with only a bit of the prehistoric mantle still remaining. The metals here are much more accessible and abundant, and so 4.5 billion sophonts currently inhabit Svolun.

Minor Moons


Kailä is the closest overall moon to Jivario, being only at around 33,000 km from Jivario's surface at most times. It is quite small at just 13 kilometres across, and so is effective as a skyhook for any Jivarian activities to do with space.


Riyald is an interesting moon. Located on the L3 point of Ardehas' orbit, Riyald is effectively a trojan of Ardehas. It has the same orbital period and eccentricity and inclination as Ardehas and is effectively in a 1:1 resonance with it. Other than that though, Riyald is just another asteroid moon, around 40 km across.


Vaten is the last moon of Jivario. It is by far the most boring of Jivario's moons, being just a captured asteroid. It is being mined for resources such as water and metals, just like any other asteroid. Plans have been made to turn Vaten into a large asteroid habitat, but it seems unlikely they will go into action.


Nearly 4 billion years ago, Jivario formed in a disk of gas and dust around the young Cruiden, in the Telmarai Cluster. It formed farther than it currently is, at around 0.8 AU, but after the great Criuden migration, Jivario settled into its new orbit, which occured around 11 million years after Jivario's formation.

Around 35 million years into Jivario's existence, a smaller world, around 7% of its mass, crashed into it. This caused Jivario's rotational period to lengthen considerably, from 11.2 hours to 46.3 hours. The axial tilt was also thrown into chaos, likely wobbling between 25 and 60 degrees. This period of unpredictability was known as the "10 millions of randomness" due to the randomness of Jivario's climate, which would drastically change every few years. This period was extremely inhospitable, but in the process, the debris created by the collision created 3 major moons - Ardehas, Svolun, and a smaller major moon that is not present today, which orbited between Ardehas and Svolun. The moon was in a very unstable orbit, in between Ardehas and Svolun. Only a few hundred years after its formation, it crashed into Svolun, completely obliterating itself and melting off most of Svolun's mantle, which is why it is so dense today.

For the next 3.91 billion years, Jivario was stabilising its temperate climate, similar to the one we see today. Everytime its home cluster, the Telmarai Cluster, bursted, there was an enrichment in heavy elements. But its peaceful presence would be brusquely interrupted in 54693, when a scout ship sent from Aziel was exploring the Telmarai Cluster. It came across Criuden, and did a brief scan of its worlds, when it came across Jivario. The ship's AI immediately noticed how Aziel-like Jivario was, and was sent back to Aziel to report its findings. Later that year, the first Azielian cargo was deployed at Jivario, which would be used for a permanent colony, and the crew arrived on Nov. 20th, 54693 CE, at Jivario, at a crater known as Larazus crater (yes, landmarks on Jivario had been named), in the southern hemisphere, and thus, Larazus City was born.

Initially, it was a small settlement of just a few hundred individuals. But as the planet proved its habitability, many new missions with many settlers came and Larazus City (Initially called TelSet-1) grew quickly, becoming an important place in the young human presence in Cosmoria, initially being the furthest major outpost for a few hundred years.

Soon after, places all around Jivario were settled and named, and the HDI of Jivario peaked for a few decades at over 0.99, a record number.