On 12/15/2012 8:13 PM, Fred J. McCall wrote:
bob haller wrote:

On Friday, thrusters on each satellite will fire to guide the
spacecraft toward the unnamed mountain. The maneuver will also ensure
the satellites avoid striking landing sites from the Apollo, Surveyor
and Soviet space programs. Engineers calculated there was a 1-
in-125,000 chance the satellites would hit one of the heritage landing
sites, according to David Lehman, GRAIL project manager at NASA's Jet
Propulsion Laboratory


I'm sorry, but that's an insane set of probabilities! I don't believe
it.

Well, it depends on how you define "striking landing sites". A direct
impact is as you know very improbable. But, there could be a speck of
dust ejected into one of Armstrong's footstep, even if the actual impact
is 1000 km away.


Alain Fournier