Terra (The Expanse)

Terra, also known as Earth, is the third planet from Sol, named after the Latin word for land and ground and the goddess of Earth, it is the home of the human species. Terra is mostly just a population center, with nothing that is really special. The reason why Terra is not too important is the fact that it is so big, Terra has a lot of gravity, meaning that it is difficult to get of the planet. Luckily it has already solved this problem with the orbital ring. The planet is extremely overpopulated, with around 15 billion inhabitants, over 90% of those live in cities. The current major employer is holding back the sea, since 2015 the sea level has risen by 5 meters. Man has been able to stop global warming and sea level rise, but seems to be incapable of reversing it. Its major export is technology and art, as it is still the center of art in human space.

Floating Islands
The oceans of Terra originally covered around the 71% of the area of the planet. In the late 22nd and early 23rd century the colonisation of the ocean began. One of the first and most common things to this day are mobile islands, these floating islands are closer to a cruise ship than a city and often house a sport stadium (like the Olympic Stadium untill the Olympic Games were canceled in 2511), an amusement park, a museum or something else. Some floating islands were even purposefully designed to fish or extract resources, these are also most of the time mobile to search for new resources or avoid overfishing a certain location. Most floating cities are made up of either square or hexagonal standardized modules who can rearrange or move to another city. The Pacific and Atlantic were also home to several airport-islands, these islands were home to an airport, hotels and recreation, meaning that planes have to be less specialized to fly over these oceans, these islands normally also held fuel, since this fuel is less dense than water it adds to their buoyancy. Most of these islands later turned into cities with small spaceports. Floating islands were used to clean up the plastic soup as they are highly resourceful and recycle almost everything. Most floating islands, especially floating factories and reactors use the ocean water as a coolant. Another common artificial island type is the fake-iceberg city, these are made up of a small plateau on the top, usually holding up to 3000 people and a massive net of underwater nutrient-absorbing cables where plants anchor themselves on. These fake-iceberg cities are named this way because, just like an iceberg, only a small piece sticks out of the water and the rest is an underwater farm. Yet another type is the jellyfish island, these are similar to fake-iceberg islands, but instead of having a massive farm underwater, they have an underwater city.

Underwater Structures
The bottom of the ocean is home to several underwater structures. One of the most well known is Charybdis, named after the sea monster in Greek mythology, Charybdis is a prison, holding thousands of people and is one of the best isolated prisons there is, even more so that the ones on the moon. It is similar to most other underwater structures: a simple concrete (or metal) dome, though most structures have windows, Charybdis, for obvious reasons, doesn’t. Underwater farms also exist, these farms are usually able to float and dive down during storms and night to a depth of about 50 meters, some even stay at said depth forever since light can still reach the plants at a depth of 50 meters. The ocean floor is also home to thousands of geothermal reactors and even several abandoned underwater fission plants. Several hyperloop tracks are buried underneath the ocean floor, these accelerate at around .3G, this means that they reach mach 1 in just under 2 minutes and mach 10 in 19 minutes 16 seconds. A trip from London to New York takes (accounting for turns and deceleration) around the 50 minutes. Underwater mining is also very common, with automatous mining submarines using tentacles to grab rocks and bring them to the surface or even a mobile underwater factory located within a submarine. A common vehicle is besides trains also the underwater car, these self-driving cars have the ability ti go underwater and go down to nearly a kilometer. The biggest company of underwater cars is Aquabaino, who also produce high pressure vehicles for other worlds and spaceships. Scylla is the most well known underwater building, located 0°N 0°E, it is the tallest tower on earth being 5 Km tall, a floating island named Null Island is anchored to Scylla. Scylla is a city all on its own, housing several million people it is often seen as the capital of the ocean. It is home to houses, shops, harbors, docking ports for submarines, monuments, factories, stations and even an elevator that goes up one of the wires that connect it to Null Island.

Highway Cities
Over the 1445 years that have passed since 2018 most remnants of highways on Terra have disappeared except 1: the highway city. A highway city is a city that is built to fit the highways instead of the highways being build to fit the cities. They were originally created to stop traffic jams in cities as even self-driving cars could have accidents and cause bad traffic in a city. A highway would be placed on top of a residential area, people use elevators to get around and cars can go down using small side-streets. Even though the highways on top of the cities have mostly disappeared, the strange shape can still be seen, though it isn’t as obvious as a few centuries ago. Sub-pontis, a part of the highway city of Plefmont, a city with 2 million inhabitants, is one of the most famous highway city districts and has a population of around the 6,000 inhabitants. In total about 500 million people live in highway cities around the world.

Deserts
In the year 3463 man has reclaimed many of the deserts on earth and turned them into habitable areas with billions of people living in them. LNC was used to bind the sandy and arid soil, water was brought here using underground and surface pipes along with artificial lakes and rivers. Artificial salt lakes were domed over and evaporated using convex lenses, the water condensed on the side of the dome and dripped down into pipes. Another way of reclaiming the desert was known as Inward expansion, this technique was used in the Thar desert and after 476 years the technique managed to successfully green the desert by the year 2685. The technique works by placing plants around the boundary of the desert and oases in the desert, then gradually plant them further in and away from the oases to slowly green the desert, this technique was only used once as it was extremely slow (about 420 square kilometers every year). The deserts are currently home to countless cities like Pheathon and Psamathe. The water in the underground and surface pipes and the artificial rivers and lakes cooled the area down.

Original
The first permanent settlements in the polar regions were established in the 2040s when the mining ban from the Antarctic Treaty System came under review and was sacked, several oil companies placed small bases on Antarctica in search for oil. Most of these bases had minimal staff, 20 people at most, during the third world war most of these mining platforms became temporarily government property, causing several battles to be fought out in the Antarctic. By the 2100s most of the oil on Antarctica had already been exported and most people left the continent. The Arctic melted, creating a whole new region for companies and nations to send ships through, giving it the name The Arctic Heaven For Trade and causing the Arctic Tensions in the 2030s and 2040s.

Current
The Arctic is currently an ocean (the Arctic ocean), but the Antarctic does still exist. A lot of ice in Antarctica has melted, but it is still very cold there and there’s still a lot of ice. The entire continent is home to only 100 million people. Their food is produced in farms that are located under domes. These domes get their light from the sun and LEDs spectrum-tailored for photosynthesis, powered by an RTG underground, whose waist heat warms the ground. Water is provided by melting the surrounding ice. The RTG is most often powered with strontium-90. The capital of Antarctica is Notos, named after the Greek god of the south wind, the city is located inside an artificial underground canyon and was once a mining city. Notos has a population of 10 million.



Orbital rings
Terra is surrounded by 3 orbital rings: Iris, Astraios and Chandra at an altitude of 80, 160 and 320 km respectively. The metal rings have currents running through them, creating magnetic field, many magnetic rings with a diameter of nearly 500 m float around the rings, carrying a metal sheath, which is stationary with respect to the surface. Chandra is a bit of an exception, as it is actually 2 rings, with the smaller rings carrying platforms instead of a sheath.

The rings are connected to the surface and each other with space elevators, though they resemble trains more. They allow people and cargo to travel across Terra in a matter of hours. There are also electromagnetic rails across the top of the ring which can launch ships out of orbit and catch approaching ones. A large amount of the Terran fleet is also docked at the rings, together with hundreds of trade vessels. Countless cities and factories are on the sheath and the attached platforms, housing well over a billion people. The rings also carry the bulk of Terra’s anti-meteor arsenal. Iris forms the center of the InterContinental Power Transfer or ICPT, by using 280K superconductors to transport energy from fusion reactors to cities.