[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Break off point between air burst and ground impacts

List Member 

There has been much talk about impact rates recently. Like bolide and
meteor increased rates.  While I do feel that the professional are getting
better and better at determining rates to more they learn, it still remains
in the relm of probabilities and to some people's opinion speculation.

Something everyone can agree on is this. There is a direct relationship
between size of rock and the number of space object speeding around the
solar system. In other words, there are fewer 20 km rocks than 20 meter
rocks. I will not go into exact figures but the number difference is very
very large. Logic dictates that the smaller rockx hit Earth far more often.
That being said I want to toss out a figure I read recently.
Stone rocks from space less that 200 meters (about 600 feet) will always
cause an air burst and never impact the ground. Only local geographical
damage being the results. Not much consolation to the people standing under
it but not a global event at any rate. (Of cause this this does not apply
to the rarer solid iron meteor which due to increase density would impact
ground). 
I gleamed this fact from the recent Dr Jack Hill abstract who is studying
using simulators and super computers at Los Alamos Nat Labs.  

I was wonder whether some of the people on the list (wayne, calvin,lew,
phil, geozay, kim, cathy, Jin etc.etc. ) know some additional facts on this
question only? The density of the rocks have a very important component to
the calculation.


Victor