Asteroid mining is an activity, where humans are trying to harvest resources from the asteroids. Resources from one asteroid can be incredibly valuable. Asteroid mining might be the reason, why humans colonize space, as the resources of Earth are running out.
Choosing an asteroid
The amount of asteroids in the Solar System is really large. If we’re only counting the objects that are over 100 meters in diameter, there are 150 million asteroids in the inner parts of the Solar System. If we also count smaller objects, the amount of asteroids is multiplied. All asteroids, however, are not created equal, so time should be used to find valuable asteroids.
Most likely the first asteroids we will mine will be near-Earth asteroids. Many asteroids have trajectories, than on which they will be nearby Earth from time to time. We could send mining robots there when the asteroid is nearby, and return the resources to the Earth when it makes a close pass again. By time, we could also start harvesting resources from asteroids that are farther from the Earth.
One thing that one should keep in mind when choosing an asteroid to mine to, is its composition. There are different asteroids, but many have valuable materials, such as gold, iridium, silver, osmium, palladium, platinum and tungsten. More common materials, such as iron and aluminium can also be found, which could be used to build autonomous mining robots, for example.
The location of the asteroid and its composition and size will define, if we should mine an asteroid. In the beginning, we will be most likely mining nearby asteroids that have the most valuable materials, but by time we will also mine asteroids that are farther away.
Valuable materials can be collected from the asteroids with multiple ways. The easiest way would be to collect material only from the surface. This would be easiest to do, but the amount of material collected would not be very large. If the materials were magnetic, we could also use magnets to collect them.
We could also build shafts on the asteroids. This requires more complicated technology, but the amount of collected material would also be larger. Shafts could be done on larger asteroids, where there is material to mine for years.
Humans or robots?
Asteroids will be mostly mined by robots, but humans will still might play a part on the mining process. This largely depends on what kind of technology we will be able to develop. Using remote controlled robots from a large distance is challenging because of the delay, so if the robots would be used, they’d have to be autonomous or operated by a human close by.
One interesting plan is to use self-replicating robots. If a single robot like this would be planted on an asteroid, it could replicate itself from the materials the asteroid has. With this technology, single asteroid could be mined very quickly. We are still far from that, though, and would need to develop the technology greatly.
Asteroid mining will give huge financial gains to the people and companies, who manage to develop technologies for it. Asteroid mining might be very profitable business in the future, as the resources of the Earth are running out.