Alan Rubin and I grappled with this issue in our article in
Meteorite! 10 years ago, "What is a meteorite? The pursuit of a
comprehensive definition." We wanted a definition that would exclude
things like tektites from being called meteorites. Our definition
then said that, to be called a meteorite, an object had to escape
the dominant gravitational influence of its parent body. In this
case, we would say that a terrestrial meteorite would be an object
ejected from earth by natural causes (i.e., by impact), which entered
an orbit around the sun and later was re-accreted by the earth.
Nothing like this has ever been found. Its distinguishing properties
might be a fusion crust, evidence for cosmic-ray exposure in space,
and lithology that is completely exotic for its find
location. Without an exposure history (or being an observed fall) it
would be a very tough sell... a Wingstar.
Jeff
At 12:24 AM 5/30/2008, Pete Shugar wrote:
Hello list,
I've given this more than just a passing thought as I think this is
a very intreguing question.
If an impactor smacks into the moon with enough energy, objects will
be dislodged.
If they make it to earth intact, we have a luner meteorite.
Same goes for Mars and Astroid 4Vesta.
So,.....suppose we have a very high speed impactor that hits earth,
and dislodges material that is now in orbit. If the material crosses
Earth's orbit again, and survives to the surface of earth, would it
be modified in it's appearance to the extent that it would be seen
as a meteorite and not just another rock?
Has anything ever been found that might be in this class of material?
Would there be anything that would set it apart as a different rock/meteorite?
Pete
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