[meteorite-list] What killed off megafauna?

From: E.P. Grondine <epgrondine_at_meteoritecentral.com>
Date: Sun, 26 Jun 2016 16:10:52 +0000 (UTC)
Message-ID: <601466113.1885454.1466957452542.JavaMail.yahoo_at_mail.yahoo.com>

Hi Rob, Doug -

(Glad to hear that you're doing okay, Doug)

What both of you need to do is to take the perspective of a potential impactor passing through the inner solar system,
as seen in the first few seconds of this video:
https://www.youtube.com/watch?v=GDrBIKOR01c

The basic geometry of the problem is set out here:
https://www.youtube.com/watch?v=qTDcfI2dabk

If it makes it easier,
think of the Earth-Moon system as a pair of girls at a darkly lit party,
and yourself as a young man.
(A variant of the famous mathematical problem of the drunk's walk at the frat party.)
While you may be attracted to the "prettier" (in terms of gravity/area) Moon,
you are far more likely to run into her much larger "wingman", the Earth.
Sorry, but that is just the way it is.

At first, you're getting a warm fuzzy feeling (gravity) from the combined Earth/Moon system.
That warm fuzzy feeling varies by the cubes of the radius of each of the two bodies,
and is located somewhere amongst them.

On your approach to the Earth/Moon system, you see your landing area (for only part of the month, see second video)
in terms of area, which varies by the square of the radius.
But of course gravity also varies by distance,
so as you get close to theses two
you're getting far more of that warm fuzzy feeling from the Earth,rather than the Moon.
You head that way.

You can use any computer language you prefer to model this system,
and run it on any machine you like.
But as a check on your computer model, you have to rely on the data.
In this case, compare the data on smaller impactors from the Moon,
(Apollo seismic and optical astronomy)
with the data from the reconnaissance systems which have been operating
on the Earth since the 1950's,
and "alarming" the "stuff" out of those looking at the data from them.

If there is a difference between your model's results and the data, then your model is defective.
 
(An entertaining video on phonetic loading,
the diameters of lunar craters,
typing monkeys, and other natural phenomena:
https://www.youtube.com/watch?v=fCn8zs912OE)

good hunting,
E.P.

PS - Will NEOcam make meteorite hunting far easier?
Will the increased supply drive down prices even further?
Received on Sun 26 Jun 2016 12:10:52 PM PDT