Before I can suggest required proof for intersection, let's define what we mean by intersection. Is it: 1. Us finding relics on earth or else where of a long

Before I can suggest required proof for intersection, let's define what we mean by intersection. Is it: 1. Us finding relics on earth or else where of a long dead alien civilization? 2. Us being monitored by an advanced race of ET? 3. Them living amongst us? 4. Them influencing us, dealing with world governments? I guess each scenario will require different types of proof. I'm not sure how to proceed without defining scope.