"valtih1978" wrote in message
...

every bit of the mass eventually hits the earth as nothing is "burned" so
much as ablaited


I mean that small particles are easy to be stopped by atmosphere and
possess no threat. Right?

obviously you have never heard of cosmic rays which are small particles that
strike the atmosphere at close to the speed of light...much potential damage
there.

outside of that, you are correct. However the term "small" is is relative
and in communications such as these can lead to much confusion. And then
there is the question of "how many" small particles are you talking about?
individually small particles pose little or no threat but a large mass of
individual particles can pose a grave threat.....tungusta comes to mind.