> On the contrary, Mars has all the resources of asteroids but the advantage of a water cycle that has concentrated and reformed minerals like on Earth. The wa

> On the contrary, Mars has all the resources of asteroids but the advantage of a water cycle that has concentrated and reformed minerals like on Earth. The water cycle concentrates diffuse elements into usable mineral deposits, yes. But those elements are only diffuse in the first place because of the planetary environment. The base abundance of industrially useful elements in asteroids can be tens, hundreds, or thousands of times higher than Earth (or Mars) precisely because these materials sank to the core or mantle of planets, or get chemically locked up in expensive to refine oxides. Indeed many of the rare metals we prize are actually of asteroidal origin, because they have been completely depleted in the Earth's crust in geologic antiquity. What's more, chondritic or M-class asteroids typically have extremely accessible minerals, such as pure metals already in reduced form, or mixtures of loosely compacted minerals that can be sorted with a crusher and a centrifuge.