Circumstance

Circumstance is an ocean world and the smallest of the three main colonies in the Epsilon Eridani system. Sometimes regarded as the gateway to the system due to its orbital position, Circumstance has also become renowned for its universities and courts of justice. There is an uncommonly even split between the planet's surface and orbital populations, with the planetside population dwelling mostly in floating cities.

Topography and climate
Influenced by its position right on the edge of the system's Goldilocks zone, Circumstance's surface is divided between the vast ice sheets that run down from the poles, and a saline ocean which resides beneath the snow and only reaches the surface close to the equator. The oceans have an average depth of two to three kilometers, which hide a number of super-massive craters which were created by asteroids from the inner belt. Aside from the Mu plateau in the southern hemisphere, the edges of these craters are the primary places that rise above sea level, creating a circular arrangement of islands that are visible from orbit. These are typically too thin to allow for people to live on permanently, so most of the planet's population reside on cities which are supposed by immense seasteads. Similar to Earth's seasteads, many of the artificial islands are made to be mobile, forming a lifestyle of sorts for their inhabitants. While the cities were named after space bodies found in Sol, the geographical elements were named after nautical themes.

Biosphere
Although Circumstance has native, primitive forms of life that reside close to the ocean floor, most of the planet's biosphere was introduced by humanity. By far the most iconic creatures were its cetacean mammals, particularly dolphins and orcas. The Circumstancian aqua-farmers took advantage of their intelligence by training wild populations to herd fish into concentrated groups, where fishing nets would quickly scoop them up. Particularly advanced forms of technology, such as neural implants, were not uncommon on domesticated individuals, particularly for the purpose of better conveying orders.

Economy
Because of its proximity to the system's inner asteroid belt, as well as the huge amount of water and gas locked up within its ice sheets, Circumstance's greatest early asset was its mining and refining potential. A large number of extrasolar corporations established substantial infrastructure in its orbit, which exported not only raw materials such as metals, but especially mixtures that were vital in terraforming. This industry gradually declined over time, yet even by the modern day, a small number of facilities were still retained for this purpose.

Circumstance was most famous for its education and juridical elements, with lawyers that were educated here being considered the finest in human space. The planet is home to the UEG's Colonial Courts, most notably the Supreme Court of the Inner Colonies, and this sees a large, diverse range of individuals traveling to and from the planet to attend various cases. Their outcomes often decide the entire policy-making process in all of Human Space. To support this, the well-funded universities compete with each other to pick the brightest minds in the colonies, with students sometimes coming from as far away as the edge of inhabited space. These universities also support various research programs for corporations and even government organizations such as the Office of Naval Intelligence. A number of other industries on Circumstance exist purely because of the influx of off-world students, such as tourism and accommodation.

An important contributor to the planet's economy was its aquacultural industry, where various forms of seafood and sea-based resources are exported offworld. These farming processes are fairly automated and efficient, thanks to the relative wealth of the population in comparison to the rest of human space. After the Human-Covenant War, any and all sources of food became extremely highly prized thanks to the destruction of so many agriworlds meant that the planet's aquaculture facilities were among the first to recover, which in term made Circumstance a regional but temporary economic superpower. Many of the refugees who ended up on the planet sought to create small, self-sustaining communities of aquafarms on makeshift seasteads.

Defenses
Circumstance was defended by an array of orbital weapon platforms and various other UNSC Aerospace Force assets, along with a dedicated squadron of the Navy's Epsilon Eridani Fleet. Surface defenses included mainly UNSC Army maritime forces, including a number of aircraft carriers, mobile MAC guns, missile subs, and various others.

Satellites
Circumstance has no moon. However, its orbital space is home to one of the most bustling orbital communities in the Human Sphere outside Sol, with both a large permanent population and transient visitors. By far the largest of the orbitals is Niven Station, one of the original stations built to support the colonization of the Epsilon Eridani system. Niven Station is also the largest spin-gravity station ever built in human territory, having been built with three 770-meter rings and expanded until the Dzhanibekov Effect threatened its stability. Today, it houses the Colonial Courts along with the system's largest commercial port. There are also a handful of Cylinder- and Carousel-type habitats with wide open spaces and numerous lesser stations. Circumstance's orbital space serves as the system's primary "parking swarm" and orbital fusion fuel depot for civilian vessels awaiting to move further in-system to Tribute and Reach, or to the asteroid belts and as far as the gas giants Aegir and Tantalus.