From: Doug Jones (djones@xcor.com)
Date: Tue Jun 26 2001 - 23:02:31 MDT
Mike Lorrey wrote:
>
> Significant volcanic activity would have resulted from a change in the
> orbit of the moon caused by the influence of a number of close flybys
> over several million years of the object that wound up colliding at 65
> million years. For example, an impact or flyby of the moon which would
> have caused it to either come closer to earth (increasing tidal stress
> but decreasing tortional stress on earth's rotational velocity) on a
> faster orbit or else move away from earth into a slower orbit (thus
> decreasing tidal stress but increasing tortional stress on earth's
> rotational velocity) would have significantly affected tectonic forces
> during that period. Also a change in the moon's angle of inclination
> would have caused similar release of tectonic forces.
Mike, any object large enough to significantly perturb the moon's orbit
would be large enough to pasteurize the planet on impact. Back of the
envelope calculation:
Earth: 5.97 E24 kg
Moon: 7.35 E22 kg
Juno: 2 E19 kg
(1/3675 of moon- Any smaller object is not credible for causing orbital
changes to the moon.)
Impact velocity: 20 km/s (minimum possible is 11.2)
Impact energy: 4E27 joules
Chixulub is estimated at 100 million MT, a mere 1E23 J, 40,000 times
less energy than this impactor. I think you're kinda talking off the
top of your head about orbital perterbation of the moon leading to tidal
perterbation of the earth...
-- Doug Jones, Rocket Plumber XCOR Aerospace
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