[meteorite-list] Fire caused by meteorites.. Is it possible?

[Chris Peterson]

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
>