[meteorite-list] Speed that meteors enter dark flight?

[Chris Peterson]

It depends on the mass of the body. But realistically, under "typical" 
conditions that might lead to meteorite production, I think it's safe to 
say that this happens almost instantly.

For example, a 100 kg stone that survives to 20 km height will be 
experiencing a deceleration of ~1500 m/s^2. A 10 kg stone will 
experience ~4000 m/s^2. Of course, no stone is likely to survive the 
forces that would result without breaking up. You need to play all sorts 
of games with different parameters for mass, speed, and height to find 
survivable scenarios. They all produce a very short period of dark 
flight before terminal velocity.

This is why the retardation point is typically overhead any strewn 
field, and you don't usually have meteorites significantly down field 
from the retardation point. In fact, wind during dark flight may move 
meteorites farther than their last bit of momentum did- and that can be 
in any direction.

Chris

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

On 3/7/2012 11:45 AM, Mike Hankey wrote:
> the follow up to this question/answer I still wonder about is:
>
> after dark flight begins, how many seconds will it take to completely
> decelerate so that all forward momentum is lost after dark flight
> starts.
>
> for example: if the meteor goes dark at 4km/s how many seconds before
> it will be at 0km/s and/or what does that deceleration curve look
> like?
>