[meteorite-list] Does Friction or Ram Pressure Cause Meteor Ablation

[Chris Peterson]

"Friction" is not a great term. But the answer is both... which is 
dominant depends on the size of the meteoroid with respect to the mean 
free path between collisions with atmospheric particles.

Objects on the order of a centimeter or larger are mainly heated by ram 
pressure effects. Objects smaller than that are heated by a more complex 
process involving kinetic energy transfer due to particle collisions- 
often called friction, but actually rather different from the usual 
definition of that word.

Chris

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

On 11/18/2011 10:50 AM, JoshuaTreeMuseum wrote:
> I know it was discussed awhile back about whether atmospheric friction
> or ram pressure causes meteor ablation, but I don't remember if the
> science was ever settled. If you Google the question, the overwhelming
> majority of hits say it's friction with oxygen, argon and nitrogen
> molecules that causes the heat. Even an NAU site says this. Dig a little
> deeper and you discover claims that it's a myth, the heat is caused by
> ram pressure. So which is it, compressed air or friction?
>
> I vote for ram pressure.
>
> -----------------------------
>
> Phil Whitmer