Gizmodo recently asked an interesting question. “Why Mine Asteroids When We Can Mine the Seas?” The question is not frivolous. The #ocean floors are much more accessible than even Earth-approaching asteroids where it comes to sending out mining robots and bringing back #Raw Material. Mind, the very question has within it the either/or fallacy. If we mine asteroids, we can’t mine the sea and visa versa.
The author of the Gizmodo article ignored one big problem for large scale ocean floor mining operations, that being the environmental movement. The same people who go crazy over the building of a refinery or a pipeline are going to be incandescent in their rage at the idea of disturbing the “delicate ecosystem” of the ocean floor by ripping minerals out of it..
To be sure protecting the ocean’s environment while conducting mining operations is not a frivolous concern. But the judicious use of technology and sensible procedures makes the thing doable. Unfortunately nothing with satisfy the environmentalists. From their perspective the best way to protect the ocean floor is to not do anything on it.
Asteroids are a different matter. They are balls of rock, metal, and ice hurtling about the universe. Ripping the guts out of them for useful stuff is not going to disturb any ecology because asteroids don’t have any.
Besides ocean mining and asteroid mining would serve two different purposes. The former would provide the raw material to keep technological civilization going on Earth. The latter would provide the same for extending that civilization beyond the home planet,
Currently anything that goes into space has to fit on top of a rocket. Anything bigger, such as the International Space Station, has to be assembled in space at great expense for a lengthy period..
Asteroid and Lunar mining will allow for the construction of large-scale structures in space. Mining robots would extract materials that would be turned into parts by 3D printers. The parts would then be assembled by robots into everything from space telescopes to orbiting habitats to industrial facilities.
Water can be mined to create rocket fuel, which would turn asteroids and the moon into refueling stops for spacecraft headed to destinations in deep space, such as Mars. Fuel for an entire voyage would no longer have to be lifted from Earth’s deep gravity field.
So, on the question of ocean mining vs. asteroid mining, the answer would seem to be both.