[meteorite-list] clusters of holes on the ground on Mars and Earth -- impact swarms: Dennis Cox: Rich Murray 2011.07.30

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Sat, 30 Jul 2011 15:20:34 -0500
Message-ID: <42CFE6283B794C99B46C2D8D8B0F53BA_at_ATARIENGINE2>

> there is no reason to assume those
> in the images from Mars did either...
> Until we?ve been there on the ground.

The reasons are these. The "crater-counters"
have identified 220,000 unambiguous craters
of every age on Mars, exclusive of any volcanic
or ambiguous features, of which there are many
thousands, but they are a tiny minority.

On the Earth, the number of verified craters is
less than 200. I grant you, many more will be
verified, but the Earth should have 2.6 times as
many on its land surface as Mars does, 500,000..

It did, cumulatively, have that half million craters,
but they are gone because the Earth is, as the
freshman geology clich? has it, a "dynamic planet."

On the Earth, the default assumption for a hole
is geological process (of whatever kind). On Mars,
it is Splat! And both are likely right in the first
approximation.

I bet if you checked the geological literature, you
would find that many of these features have been
visited. Perhaps not investigated with impact in
mind, but it should be possible to isolate those
with no obvious terrestrial cause.

About 1.4-mile from my house is a perfectly conical
hole 300 feet across, very fresh and grass-overgrown.
Since it (and I) live on top of an old limestone cliff
in a wet climate, I know perfectly well how it formed.
I have no need to scratch for any shocked materials.

I only hope one doesn't open up under my house...


Sterling K. Webb
-----------------------------------------------------------------
----- Original Message -----
From: "Rich Murray" <rmforall at gmail.com>
To: <meteorite-list at meteoritecentral.com>; "michael barron"
<mhbarron at gmail.com>; "Rich Murray" <rmforall at gmail.com>; "Rich Murray"
<rmforall at comcast.net>
Sent: Saturday, July 30, 2011 1:56 PM
Subject: [meteorite-list] clusters of holes on the ground on Mars and
Earth -- impact swarms: Dennis Cox: Rich Murray 2011.07.30


clusters of holes on the ground on Mars and Earth -- impact swarms:
Dennis Cox: Rich Murray 2011.07.30

http://craterhunter.wordpress.com/2011/07/30/holes-in-the-ground/

Holes in the ground

>From Wikipedia we read that ?Crater? may refer to:

In landforms:

Impact crater, caused by two celestial bodies impacting each other,
such as a meteorite hitting a planet
Volcanic crater or caldera, formed by volcanic activity
Subsidence crater, from an underground (usually nuclear) explosion
A maar crater, a relief crater caused by a phreatic eruption or
explosion
pit crater, a crater that forms through sinking of the surface and not
as a vent for lava
Crater lake
Explosion crater, a hole formed in the ground produced by an explosion
near or below the surface.

Here we see a small Crater field on Mars.
The largest of the small craters you see here is about 500 meters
across.
The consensus is that they are all impact craters.
The problems we have here is in the uniform condition of the craters,
and their sizes, and distribution.

If, as is assumed, impact events do indeed happen at a steady rate,
and these impacts all happened one at a time, over a long period, then
we should see some variation of condition from the earliest, to the
most recent.
Also, they are concentrated into fields of craters surrounded by large
areas with no craters at all.
If they fell one at a time, then they should be evenly distributed all
over entire the surface of the planet.
They could only be in a concentrated cluster like this, in exactly the
same condition, if they all fell at the same time, in a meteoroid
swarm.

http://craterhunter.files.wordpress.com/2011/07/mars1.jpg

http://craterhunter.files.wordpress.com/2011/07/mars2_thumb.jpg?w=474&h=323

On Mars, it is assumed without question that we are looking at impact
craters.
But here on Earth, if we see the same fractal distribution of craters,
the tendency is to deny that so many impact craters could happen in a
terrestrial surface;
much less that a large cluster of small fragments could hit all at the
same time.

Our astronomers tell us that a meteoroid swarm of small fragments is a
more probable event, than a large, solid bolide.
Yet most geologists agree that such things cannot be?.
At least, not here on Earth.

But we are orbiting around in the very same shooting gallery as Mars.
And in central, and eastern, New Mexico, there are thousands of small
craters.
All in the very same geologic condition.
They are a bit small compared to the ones we see above.
But the New Mexico craters have exactly the same fractal distribution
as some of the crater fields on Mars.
And except for differences in weathering that can be accounted for by
different atmospheric conditions, they are in the very same geologic
condition.

https://skydrive.live.com/?cid=5d6b9f6c30c6fe9f&sc=photos&id=5D6B9F6C30C6FE9F%211643
View Full Album

If those in New Mexico didn?t form by impact, there is no reason to
assume those in the images from Mars did either.

Until we?ve been there on the ground.

JULY 30, 2011 AT 9:37 AM
Dennis Cox dragon-hunter at live.com
Fresno, California

Impact melt formation by low-altitude airburst processes, evidence from
small terrestrial craters and numerical modeling, H E Newsom & MBE
Boslough
2008 Mar 2p abstract: Rich Murray 2010.11.17
http://rmforall.blogspot.com/2010_11_01_archive.htm
Wednesday, November 17, 2010
[ at end of each long page, click on Older Posts ]
http://groups.yahoo.com/group/astrodeep/message/73
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Received on Sat 30 Jul 2011 04:20:34 PM PDT