Using remote viewing, I see that this is a Reptilian space craft. This sighting wave was the result of the shoot down of a Reptilian craft in Holland by the RAF. This was in violation of orders from NATO. Military aircraft of NATO members were told not to shoot at UFOs. The RAF not only shot one down, but took it to the UK where it remains to this day. The Reptilians are very angry about this and still want it back. The triangles were seen mostly in Belgium as NATO headquarters was located there.