Re: starship-design: spinning up the Moon

["bugzapper" <bugzappr@bellsouth.net>]

From: Steve VanDevender
> at 50 km/s you'd need a mass of comets/asteroids of 1.08 * 10^19 kg
> about 1/6780 the mass of the Moon
> to get the Moon spun up.
>
> that translates into a pretty huge
> quantity of comets.

Thanks a lot for this hard data, Steve. And the work you did, to bring it to
us. We need more of this approach in here, facts with numbers. I admit 10^19
kg is pretty heavy, if your impactors are ~10^7 or 10^8 kg each. This was a
low probability anyway, for if anyone were settled on the Moon you could
never land a single rock. Rethinking time.

By the way, my friend informed me Frederik Pohl in "Mining the Oort" (Del
Rey, 1992; ISBN 0-345-37199-2) anticipated the use of volatile ices to build
the atmosphere of Mars. His Mars settlers just dodged the incoming comet
fragments!

Johnny Thunderbird