Mars transport name?

[...Ceres...]
> spectra? Given its large size, we would expect to find a planetary
> arangement of a mantle, core and crust.

The nice thing about asteroids, IMHO, is that they have undergone
cycles of differentiation and fragmentation that (in certain cases)
give access to (differentiated) core material without having to dig
for it. This is the essence of what makes PGM mining in NEAs
potentially very attractive (if you can find the right NEA). Going
to a planetessimal that's small enough to have lousy gravity (making
surface operations difficult) but big enough to be differentiated
seems to me like one of the worst possible options. For water and
extinct comet seems like the best bet. For other materials, asteroids
representing a shattered larger body (so you get core or mantle material
without having to dig through crust) seems like the way to go. The
only advantage of an intact differentiated body in the Ceres size range
seems to me to be that you have everything in one place. Since digging
is going to be more expensive in energy than transport from a nearby
smaller asteroid, I don't see the benefit.

as always, YMMV,
......Andrew

Andrew Case
acase@...
Institute for Plasma Research
University of Maryland, College Park |