The most convincing would actually be contact. Actual public contact seen by hundreds.....and not under the cover of darkness. Broad daylight landing and actual contact.

Until something like that occurs, there hasn't been anything convincing to date.

I think the best evidence is Beverly Kidd.

I mean just look how she keeps shape shifting for no reason, AND show knows so much about aliens and stuff. Something's up.

I am not agreeing with your thread title AT ALL.

You have a thread title talking about evidence that alien civilizations exist, then link to UFO cases.

IN PARTICULAR the Phoenix "lights", if we simply assume that the black triangles were really SEEN...who says those are alien craft? How to conclude those are evidence for an alien civilization?

I am sorry, even if we accept that the triangles over phoenix have been "real" there would be countless OTHER *possible* theories, and the "alien theory" would only be one of them. But the case ITSELF is not evidence for this, not in the slightest - it is merely evidence that people "saw something".

On a related side note, this would merit another thread, ok, there was probably already ZILLIONS of debates and talk about the Phoenix "lights" in the past...but isn't it odd that we DO NOT HAVE ONE SINGLE FART of evidence, beside those 3rd hand accounts where people say "they saw something"? This is astonishing since otherwise someone could put a feather up their *** and dance and the next day you will have youtube videos...but here we have NOTHING. So...allegedly hundreds/thousands saw "giant triangles" over a million-people city..and there exists not one single piece of photo or footage????

By the way, the footage of the flares does not count, it is commonly assumed that the flares (those LIGHTS in an arc which are usually associated with the phoenix lights) have NOTHING to do with the actual sighting of the triangles!

One of those cases which...somehow doesn't make sense to me....too many open questions. Belgium wave...better...mostly because of real evidence (radar, fighter jets chasing) and VERY reliable witnesses like police etc. Personally for me Belgian wave is the best UFO case, but also not evidence for alien civilization.