hm... why would aliens only crash in America. I'm only aware of Area 51, not any other areas in the world.

i mean, lets say thousands of alien ships pass by earth, so happen one had a mechanical failure, or due to some circumstances it malfunctioned and crashed.

Its more puzzling why it choose one spot to particularly crash in.

@robert, he said different wavelength, thus i guess the wavelength they are using is unique... The problem is, they would have to use extremely large wavelengths to travel that distance... but then there are so many objects in space to adsorb those wavelengths... i doubt aliens can pick up these em waves to easily...