Engineer,
I think what fathomak is trying to say is that if the UA actually exists, the Earth would be moving at roughly the speed of light relative to the rest of the universe.
Consequentially, the meteors that enter our atmosphere would be moving at roughly the speed of light.
Now we have collected meteorites on the ground, we understand their composition and properties very well, we have even seen some of them enter our atmosphere, and they are not moving at 3*10^m/s. They are moving fast, but not that fast.
In fact, as near as we can tell, meteors enter our atmosphere at about 30 km/s, which coincidentally is the speed RE says that the Earth rotates around the sun!
I think this is strong evidence that the UA is the incorrect model.