Orbs: Ancient Planetary Defense System

What if the wave of orb sightings… the UAPs, the metallic spheres caught by military sensors and civilian phones alike… aren’t visitors from another world at all?
What if what we’re seeing — are the sentinels of a sleeping defense system?
One built not by us, not by extraterrestrials — but by an ancient terrestrial race. A civilization older than recorded history, hidden beneath the ice of Antarctica.