Sorry, but that's just crazy. A meteoritic body that strikes the ground
at terminal velocity, as virtually all meteorites do, cannot be hot
enough to start a fire. It doesn't matter what it's made of. And in
fact, there is virtually no evidence supporting the idea that cometary
bodies produce meteorites. And finally, comets are not hot. The
temperature of a body in space depends on the ratio of absorbed to
emitted energy. Close to Earth, bodies are mostly on the cool side-
freezing or less- with the warm ones still nowhere near hot enough to
start fires. Of course, after falling through the atmosphere for a few
minutes, we expect most meteorites to be quite cold on impact- something
that has been observed.
Chris
*******************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
On 8/29/2012 3:43 PM, Gary Daniels wrote:
If the meteorite is a comet fragment, then there's no reason it can't be hot
enough upon impact to start a fire under the right conditions. Recent
evidence has shown that some comets are hot and dry not icy and some also
have gas jets on their night sides which astronomers have theorized is only
possible if they are somehow transferring (and storing) heat in their
interiors. If a comet in space can store heat then a fragment of one should
have no problem storing the heat created when entering the atmosphere. If
such a meteorite landed in the right conditions (dry grass, for instance)
then a fire could be started easily.
I've seen grass fires start from very hot lawn mowers (no sparks, just heat)
when the grass was extremely dry and there was a slight breeze to fan the
flames. I've also seen grass fires start from overheated car engines on the
side of the road (in high, dry grass.) So I see no reason why a comet
fragment/meteorite couldn't cause a fire under similar circumstances.
Whether there are any actual recorded instances of such is an entirely
different matter. :)
-Gary Daniels
______________________________________________
Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html
Meteorite-list mailing list
[email protected]
http://six.pairlist.net/mailman/listinfo/meteorite-list
