Please provide data on what would happen if an iron-rich meteorite
roughly the size of a Volkswagon Beetle struck about 30 miles north of
the city of Panhandle, Texas. Specifically:

a) How large would the impact crater be?
b) How large would the damage radius be?
c) How would the local, State, and Federal authorities find out and
respond? (Sheriff, Rangers, Homeland Security, etc.)
d) How would the scientific experts find out and respond? (Geologists,
astronomers, etc.)
e) What kinds of tests would be conducted on the impact crater (and meteorite)?
f) How much would the recovered meteorite be worth?

Perhaps the best way to answer these questions is to imagine this
hypothetical event actually occurring -- it being my job to write a
detailed report.

Thank you!

---

Clarification of Question by mistermookie-ga on 06 Feb 2005 16:25 PST

Thank you, Omnivorous; terrific start, HfShaw, I sincerely appreciate
your efforts.

As I was reading the responses, another question came to mind:

*** If a meteorite falls on private property, can the owner claim all rights to it?

In this case a 9.25 kiloton blast wouldn't leave much left, but the
answer may prove relevant.

The fate of the Panhandle awaits! Thanks again, all.

Mistermookie --

I don't have enough expertise to answer most of your questions but
there are some great resources on the website for the museum at Meteor
Crater:
http://www.meteorcrater.com/visitorcenter/mcilc.htm

Best regards,

Omnivorous-GA

A meteorite the size of a Volkswagen is not all that large, as these
things go.  A 2004 model year Beetle (according to the VW website) is
161? long.  That?s a little over 4 meters.  Let?s assume your impactor
is a meteor with a diameter of 4 m.  Iron meteors have a density of
about 8 gm/cm^3 or 8000 km/m^3.  A 4-m diameter sphere has a volume of
33.5 m^3 (V=4/3*pi*r^3), and a mass of 268 metric tons (V*density; 1
metric ton = 1000kg).

An object this size enters the Earth?s atmosphere about every 3 years.
 Objects this size do not make it to the Earth?s surface as an intact
body; they break up in the atmosphere into smaller chunks that cause
little or no damage at the surface.  To get a chunk of the size you
are talking about to actually hit the Earth?s surface, you need to
start with a much larger body in space ? on the order of 30 meters
diameter.  Objects of this size hit the Earth every couple hundred
years.

Assuming you start with something large enough to get a
Volkswagen-sized piece to hit the surface, one can use the on-line
crater-scaling calculator
(http://www.lpl.arizona.edu/tekton/crater_c.html) by Prof. Jay Melosh
at the Univ of AZ Lunar and Planetary Lab to calculate the diameter of
the crater that would result from the impact of this object.  There
are a number of variables you can play with (e.g., the nature of the
target rock, the angle of impact, impact velocity, etc.), but for a
vertical impact onto unconsolidated sediments/soils, and an impact
velocity of 17 km/sec (typical for a non-cometary impact on Earth),
the resulting crater would have a final rim-to-rim diameter of about
400 meters.  The impact would have release the energy equivalent of
9.25 kilotons of TNT (about half the Nagasaki or Hiroshima device
yields).

Jay also has an on-line calculator that will estimate the blast
effects as a function of distance from the impact point at
http://www.lpl.arizona.edu/impacteffects/.  Most of the damage from an
impact this size is actually due to the air blast as the meteor
traverses the Earth?s atmosphere.  A 30-meter initial diameter object
(about the size one would need to get chunks the size of a Volkswagen
hitting the surface) will break windows out to ~10 km from the impact
site, and wind speeds will briefly exceed hurricane force (~80mph); at
5 km, wood-frame buildings would collapse and most trees would be
blown down; at 1km, steel-frame building would be toast.  There?s no
big fireball from this size impact, and ejecta is largely contained
within a few km radius.


An impact event of almost exactly this magnitude occurred about 25,000
to 50,000 years ago, just a bit south of your hypothetical impact. 
The impact occurred in Odessa TX (about 300 miles south of the town of
Panhandle).  There are numerous websites discussing the crater and the
impact.  See:
http://www.utpb.edu/ceed/GeologicalResources/West_Texas_Geology/links/odessa_meteor.htm#top
http://www.alaska.net/~meteor/OTinfo.htm
http://www.tsha.utexas.edu/handbook/online/articles/view/MM/rym1.html
http://www.unb.ca/passc/ImpactDatabase/images/odessa.htm
http://www.texasbob.com/travel/tbt_odscrt.html
http://www.meteoritearticles.com/odessacraterarticle.html

As one might expect from my comments above, the Odessa meteor broke up
into several pieces upon entry, so there is actually a field of
smaller impact structures surrounding the main crater, which is
currently about 200 meters in diameter.

Pieces of the Odessa meteorite routinely sell for $1.00 to $2.00 per
gram on eBay.  Bigger pieces are generally worth more per gram than
smaller ones.

For comparison, the Barringer Crater (aka "Meteor Crater") in Arizona,
was formed by the impact of a ~50-meter diameter chunk of iron
meteorite.  The energy release in this impact was on the order of 18
megatons TNT.  Impacts of this size occur every 2-4 thousand years. 
The effects of an impact of this size are qualitatively different than
for the case you asked about; they produce a fireball that vaporizes
or melts a significant portion of the target rock, and the combined
thermal and blast effects are significantly more damaging.  See
http://www.lpl.arizona.edu/SIC/impact_cratering/Enviropages/Barringer/barringerstartpage.html.

HFShaw --

That's a great collection of resources and analysis.  It may not
satisfy MrMookie's entire request but I have to tell you that I loved
reading it!

Best regards,

Omnivorous-GA

Thanks, Omnivorous.  I'm not an official researcher, so I figured I'd
just give some pointers to some relevant information, and let someone
who can claim the fee provide a complete answer.

The owner of the land would own the meteorite. It is a special case,
bc the metorite hand now previous owner. See goddard v winchell.

Quantumdot is correct in that a meteorite that lands on private
property in the U.S. is the property of the landowner.  That's not
necessarily true of other countries, though.  See, for example, this
abstract from a recent Meteoritical Society meeting
(<http://www.lpi.usra.edu/meetings/metsoc2001/pdf/5150.pdf>).

You would be mistaken, however, to think that a 9.25 KT blast wouldn't
leave much left.  Again taking the example of the Odessa impact, I
would guess that hundreds to thousands of kg of material has been
recovered.  The largest pieces that have been found are on the order
of a 100-200 kg, but there are thousands of several-gram pieces
around.  Do a search on eBay, and you're sure to get some hits.