Best Evidence: Your thoughts?

This is a topic that seems to change from person to person. What do you believe to be the best evidence for visitation or artifacts that are not from planet Earth, or perhaps - from a different dimension and why?

In trying to understand phenomenon that we don't really comprehend, it seems that I find myself try to make comparisons to what I DO understand. Often, that leads to erroneous ideas.

Recently, the new book "Area 51" mentioned how observers of then new aircraft (first the U-2, then the A-12 - later the SR-71) were reporting those aircraft as "UFO" observations. That they were! No one had seen aircraft at a height of greater than 70,000 feet or even close! Nothing more than a "glint" of sunlight flashing off the initially polished aluminum skin at these phenomenal heights would, perhaps even today, lead to "What was that?"

Most of us aren't trained observers, so we know only the aircraft we are familiar with. Unusual weather or lighting can make identifying the know, challenging.

My observations of that classified as "UFO", are subject to critical review.
For example, this sighting I had in September 1965 was as a 6 1/2 year old boy. I saw what appeared to be a craft that resembled a Gemini space capsule, silently flying at low altitude (I'd say about 1000 feet in altitude) at twilight. That is what I understand and I was kid that knew what the Gemini looked like.
It wasn't until 15 years later, reading a copy of "Incident at Exeter" by John G. Fuller, that I ran across a passage in the book where an Air Force Colonel saw the same thing at the same time........Now I didn't feel so crazy.......

And I've seen more that remains unexplained to me.
My biggest goal today in seeing and hearing what others present is to try and understand what they saw, as they saw it. Being clear on what may be "added" by their experience , helps me to better get some objectivity to what is being presented.

More in the next installment.....