Given all the logistics involved, it is unlikely that humanity will ever see our way outside of the solar system to colonize the exoplanets. But the possibility of settling elsewhere inside the solar system is not far away.
NASA is planning an outpost on the moon. Missions attracted to Mars are not far away. Heck, we already have humans living off-planet (albeit for temporary static) on the International Space Station.
So is there anywhere else in the solar system that humans can build our homes? Well, according to physicist and astronomer Peka Janhunen of the Finnish Meteorological Institute in Finland, the dwarf planet Ceres is not entirely there.
Ceres is an interesting part of the rock. It hangs in the asteroid belt between Mars and Jupiter, and with its 952 kilometers (592-mi) diameter, it is believed to be both the largest known asteroid in the Solar System and the only dwarf planet closer to the Sun than Neptune.
Why Ceres? It ticks in a lot of desirable boxes, Jehennan thinks.
“Inspiration,” he writes in a printprint published on ArtXiv, “is to have a compromise with artificial gravity that allows for growth beyond the Earth’s living area, while also providing easy intra-setal travel for residents.” And has a reasonably low density of 500 population [people per] square kilometer. “
Mars and the Moon, he argues, might not be the best place for human colonies, because their natural gravity is very different from Earth. We know that astronauts face health problems when returning to Earth from a low or zero-G environment; We know very little about the effects of moving towards maturity in low gravity.
An alternative to the planetary colony model is an artificial space colony, orbiting the Sun – a space station spinning to generate a centrifugal force: G gravity.
It would also be awesome logically. If the population becomes too large for one colony, multiple settlements may be required. If many colonies orbit around the Sun, they can create other problems such as inter-settlement travel. If they are orbiting a normal body, collision avoidance becomes a problem.
Janhuen’s solution is quite clean, in fact, at least in concept: use Ceres as a basis around which spinning settlement nodes can be connected by a fixed frame.
This will not only solve the problem of holding disposal nodes together without collision capability, but will also solve the problem of materials neatly, as they can be assembled directly from a dwarf planet. Nitrogen has special significance, Janunen said, because it makes up so much of the Earth’s atmosphere.
But we also know that Ceres is very salty, and recent research suggests that it may contain a lot of water below the surface. Solar panels on the surface of a dwarf planet can easily provide space lift power to the satellite.
“Lifting material from Ceres is energetically cheaper than using a lift from space, if a space lift is used,” Janunen explains. “Because Ceres has low gravity and rotates at a relatively fast speed, space lift is possible.”
Radiation shielding, he said, can be made from 80 percent silicate regolith (rock from Ceres) and water. Habitats will be divided into rural and urban locations with depths ranging from 1.5 m to 4 m as required for trees and orchards.
Because Ceres is so far away from the Sun, mirrors can be used to inhabit sunlight, to grow crops, to illuminate, and for solar energy. These mirrors will hinge on one side of a disk-shaped satellite, like a makeup compact, and can be adjusted to collect the most sunlight as the dwarf planet revolves around the Sun.
“We use a disk geometry for magnetomaterials because its symmetry eliminates tidal torque so that reaction wheels are not needed to maintain attitude,” Janunen writes.
“Dwellings are illuminated by natural sunlight. Sunlight is focused on the disk by two plane mirrors tilted at a 45-degree angle and the desired intensity by parabolic mirrors.”
It can, as necessary, be grown by adding more habitats along the edges of the first one, possibly millions of habitats, to a lifestyle that, perhaps, is better than life on Earth.
Ultimately, there would be no natural disaster or undesirable weather, and its modularity would mean that it could increase with population. In theory, Ceres could support, Janhuen believes, 10,000 times Earth’s current population.
Of course, all of this is very speculative, and has yet to be tested. Furthermore, Januhen notes that orbital artificial gravity is still a target that remains to be realized.
For that matter, therefore space elevators, giant mirrors, and radiation are adequate shielding to protect a space colony. Orbital simulations for Ceres, and the logistics of transport to many humans outside of Mars, are also considered factors.
However, once these kinks are ejected, it will only take 22 years to build a human satellite around Serens, Janhenen calculates.
“The overall level of difficulty of executing this project is probably similar to settling Mars,” he writes.
“Delta-V and tryptime for Ceres are longer, but on the other hand a planetary landing and atmospheric weather and dust are avoided. Using a lift on Ceres would require some effort to lift the material into orbit Is, but it is energetically inexpensive. Once the material is in the high Ceres orbit, the thermal environment is uniform and energy is easy to obtain due to the absence of eclipses. “
Definitely worth thinking about, isn’t it?
Janhenen’s paper is written under the framework of the Finnish Center of Excellence in Research of Sustainable Space, available at ArcXiv.
H / T: Phys.org