It always made me giggle, people claiming this tic-tac thing was whizzing around at 50k mph, in or around 1 bar of atmosphere or something.
Considering that we know pretty much everything there is to know down to the atomic level, all matter is made from atoms - at that point, things are held together by electrons and neutrons, with the strong nuclear force (what holds all matter together and keeps it stable).
So, if aliens have managed to construct some sort of meta-material which isn't made of atoms, which can withstand unimaginable amounts of force (such as flying through 1 bar atmosphere at 50k mph) - fine, but the burden of proof for that existing is absolutely stratospheric.
It would mean everything we know is wrong - which is fine in theory, but the more we look at nature the more we appear to be right. Keeping in the back of the mind, that tomorrows discovery may succeed in proving wrong - something we thought was right, however for me - when it comes to atomic forces and our understanding of matter - I'd say that's insanely unlikely.