asteroids, meteors, meteorites (was Brad Guth's Credentials)

Pat Flannery wrote:

Chris L Peterson wrote:


I saw a television show once where a professional meteorite collector
and salesman flies over the desert at low altitude in a ultralight
aircraft with a magnetic anomaly detector mounted on it. Any blip on
the detector has a good chance of being a nickel-iron meteorite, and
he has found a lot of them this way.

I've heard this sort of thing before, but
I'm not aware of any meteorites that have been found this way. The
magnetic anomaly of a typical iron meteorite is unlikely to be
detectable from more than a few meters away.


He was flying at around 20 feet altitude, basically terrain following to
find them in a grid flight pattern; he stated he had had very good luck
with the technique.

Some hunters use metal
detectors, and it's a miserable business: outside of rich, mapped strewn
fields you can expect thousands of false positives, each of which must
be dug up. Even if you could make a magnetic map from the air (which I
doubt) I don't know how you could really use it to find anything.


Key to this technique was where he did it- in the middle of a desert
with no nearby roads, so that metallic objects would be few and far
between, vastly upping the chances of the object being a meteorite. Try
this just about anywhere else than a pretty desolate area and you are
going to be locating nuts, bolts, and nails, old chains, and the
occasional car engine block.
Now that I think about this more I wonder if he wasn't flying over the
Australian outback?

I thought the best place to find meteorites was on an ice field in the
spring. The dark spots are either dung left there by an animal or a
meteorite. If it smells its dung if not it is a meteorite :-). In Greenland,
Canadian extreme north, northern Siberia and Antarctica animals are
far between, therefore so is dung and a significant fraction of it
is meteorites.

I'm not saying that the metal detector trick doesn't work but I don't
think it is the best way to find meteorites.


Alain Fournier

On Sat, 28 Jan 2006 10:53:38 -0500, Alain Fournier
wrote:

I'm not saying that the metal detector trick doesn't work but I don't
think it is the best way to find meteorites.

Depends where you are looking, and what you are looking for. Most
meteorites are stony, and don't give a very strong response to a metal
detector. Ice fields are very good places to look- literally to look,
since the eyes are the best detectors there. But if you are looking for
iron meteorites, a metal detector is the best tool- even though it is
still very inefficient. Many meteorites have been found that way.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Alain Fournier wrote:


I'm not saying that the metal detector trick doesn't work but I don't
think it is the best way to find meteorites.


The MAD or metal detector has the advantage of finding ones that have
become buried.
The frozen surface of lakes is also supposed to be good.
Pat