Aviation experts and UFO conspirators have been perplexed by photographs of a mysterious flying object in US air space.
Grainy images showed a triangular blob with a long vapour trail flying through the clear blue skies above Amarillo, Texas next to another contrail left before it.
Defence technology blog Ares claimed this could be one of the rare times that a classified military plane has been photographed.
‘As far as I know, this sort of thing has happened only once since 1956,’ explained blogger Bill Sweetman.