Convert asteroid kintetic energy to electrical energy?

Question

Suppose we have an object, not in orbit, but on a direct collision course with Earth:

This object has kinetic potential energy w.r.t. the Earth. To convert the kinetic energy into chemical potential energy, we could theoretically do regenerative braking with large turbines that charge a battery located on the asteroid. However, this has obvious practical limitations. Is there a known way to convert the kinetic energy of the asteroid to a more useful form while it is still in space? If not, is such a thing prohibited by any theoretical considerations?

Answer 1

Perhaps a coil of electrically conductive wire on the asteroid could produce some current while passing through Earth's magnetosphere. Many meteorites have high metallic content which could cause natural slowing when passing through the magnetosphere, but this would be a small effect compared to the large kinetic energies involved between Earth and the falling objects.

Answer 2

regenerative braking

These systems simply try to stores some of the energy lost by braking, but the energy stored will always be less than the energy required to actually brake.

The idea (in conventional ground based vehicles) is that you improve fuel efficiency by using the stored energy to maintain or accelerate motion later, thus reducing fuel used. However this requires a braking mechanism that does not need fuel (or needs little - e.g. locking brakes on wheels). In the case of an asteroid you would require a braking mechanism that uses fuel (energy) to brake, and as the efficiency of the regenerative system is always (significantly) less than one, you actually use more energy braking that you store from the asteroid's deceleration.

As you can only lose energy, you might as well just use the energy (or fuel) you were going to use decelerating to just directly generate the power you wanted in the first place.

Answer 3

I think an asteroid on a collision course with Earth's surface presents too many difficulties. But an asteroid captured into orbit would be more useful. One could imagine first attaching a tether, and then suspend a turbine from the tether. As it moved through the upper atmosphere the turbine would generate electricity which could then be stored into batteries or else beamed to Earth by a microwave signal or something.