[pavement]

We’re not great at environmentally friendly mining. Mountain top removal mining, open pit mining and strip mining are brute force tactics that demonstrate a capacity for efficiency, but remain controversial because of their destructive qualities.

https://en.wikipedia.org/wiki/Surface_mining

No one will care about using destructive tactics on an asteroid, freeing everyone’s hand to not be gentle. On the other hand, much of what gets mined in space will need to stay in space. After all, what would happen, if three times the mass of planet earth were mined into managable resources? To add as much to earth’s surface would augment orbit and rotation for starters. Even bringing such mass near earth would wreak havoc on ocean tides.

[adrianN]

> The total mass of the asteroid belt is approximately 4% that of the Moon, or 22% that of Pluto, and roughly twice that of Pluto's moon Charon (whose diameter is 1200 km).

(Wikipedia)

It will take a long time before we have mined enough mass to worry about things like tides.