[meteorite-list] Impact Question

[tracy latimer]

~~snip~~
> We tend to think of nuclear reaction devices as the
> ultimate weapons, of course, but imagine if you had
> one of those railgun thingees and could speed up a
> 10 kilogram steel slug to 920 kilometers per second.
> OK, I know that's really fast, but in a vacuum with lots
> of energy on hand (about 1200 gigawatt-hours) and
> a long enough railgun, all possible in orbit somewhere,
> why not?
> 
~~snip~~

Anyone remember that old Heinlein book, The Moon Is a Harsh Mistress?  When the Lunar colonies were trying to gain independence from Earth, they started shelling Earth with the rail guns they had previously used for delivering Moon-grown grain.  Previously, the grain barges were inserted into LEO for relatively gentle splashdown or orbital retrieval; once the engineers got PO'd, they started aiming them more directly.  They made some impressive divots, as I recall.  Even though it's fiction, the physics are still sound.

Best!
Tracy Latimer