The vid was disabled at the link provided, Dolert, so I watched it on Youtube. In my opinion it is excellent material, a clear and comprehensive presentation of some of the most advanced theorizing about alien visitation. Real nice !
A man of Trachis' warning:
"When the Barbarians discharge their arrows they obscure the light of the sun by the multitude of the arrows"
Dienekes of Sparta's reply:
"Good news, for if the Medes obscure the light of the sun, the battle against them will be in the shade"
~Dienekes, Battle of Thermopylae 480 BCE [Herodotus 7.226]