Could we mine the asteroids?

Most of us know that the asteroid belt is a bunch of rocky objects that orbit the Sun between Mars and Jupiter. No one knows for sure how many there are, but it's probably more than a million, but there's only around 200 that are larger than 100 kilometers and perhaps one million with a diameter of 1 kilometer or larger. The total mass of the asteroid belt is only 4% of the Moon's mass and the four largest, namely Ceres, 4 Vesta, 2 Pallas, and 10 Hygiea account for half of the total mass, with one third in Ceres, the largest object, which is 1200 kilometers in diameter.

Many science fiction movies picture the asteroid belt as being a crowded place, but the truth is that the asteroid belt is mostly empty. If you were on one of the larger asteroids, you would have trouble seeing another one.

There are three types of asteroids: C-type, S-type and M-type. The C stands for carbonaceous; the S is for silicate; and the M means metallic. The C-type has lots of water but are not good for anything else. S-type has little water but contains lots of nickel, cobalt and some gold, palladium and rhodium. The amount of rare metals like gold is a couple of percent. The M-type is the best for metals, but that type only comprises about 10% of the asteroids.

The problem with mining asteroids is the distance. They are further away than Mars. Getting there and hauling the loot back would cost plenty. Obviously, the best idea here would be to form a colony on Mars and then go from there. The other idea would be to choose near Earth orbiting asteroids. Those are the ones that cross Earth's orbit from time to time.

The other big problem with mining asteroids is working and living on them. Since they have no magnetic field, miners would have to dig down and live under the surface to escape the radiation wrath of the Sun. The other problem would be the low gravity. None of these asteroids have any appreciable gravity. Working on them would require specialized equipment. Possible idea here is to use automated or robotic mining equipment that could be run from Earth or Mars. The only problem is the lag in communication time could make running equipment tricky.

It is possible that water, oxygen and even fuel could be obtained from the chemistry of the asteroids. However, this would require energy, some of which could be supplied by sunlight.
Obviously, there are legal and financial problems connected with this idea.

Despite all of these impediments, NASA is planning a mission (Osiris-Rex) to obtain a sample from an asteroid and determine what's really in these strange rocks. This is a first mission on the road to determining whether asteroid mining is feasible.

There are lots of ideas about asteroid mining, but what has to be determined is whether it's economical. In the long run, that's what will determine if it's feasible.

Thanks for reading.