GD wrote:

Chris L Peterson wrote in
:

On Thu, 28 Jul 2005 21:18:01 +0000 (UTC), (Brian Tung)
wrote:

Assuming a scale height of 8 km (5 mi), it's about a third of a millibar.
Less than what you get on Mars.

About 0.1 mb at 64 km (40 miles). But that probably feels like a pretty
stiff wind at 15,000 mph!

Does the effect scale up and down evenly? ie: does a 15,000 mph wind
at 0.1 mb feel just like a 1.5 mph wind at 1000 mb????

The momentum carried in the wind would be the same, but they would feel
very different. The energy delivered would be 100,000,000x more.
Frictional drag scales as the square of vehicle velocity.

And worse at these sorts of speeds and densities you generate a hot
shockwave with all sorts of horrible non-linear effects as well.

Regards,
Martin Brown