I think it would be correct to say most of it can't be accounted for however that
doesn't mean it's "alien ships"  I would guess alot of it can be explained away, 
and in the future even more will be explainable as science slowly tries to catch
up with space.

However the teather incident that was just strange.

I mean we can't even agree if certain animals/mamals even exist on our own
planet much less know enough about space to say what something may or may
not be.