Its a tough task to summarize such a mountain of evidence. But you should know

1. Nasa astronauts such as Buzz aldrin and Edgar Mitchell have given testimony both to first hand experience with extraterrestrials and their craft and to their knowledge of government involvement with these beings. To my mind, who would know better about these issues than the handful of people who have actually been in to space?

2. There are tens of thousands if not millions of highly credible eye-witness accounts, including but not limited to fighter pilots, airline pilots, the former governor of Arizona, the current prime minister of Russia, police officers, highly trained soldiers, air traffic controllers, etc.

3. There have been numerous cases of fighter pilots being scrambled by the US and Soviet airforces to pursue and intercept these craft going back to world war 2 and the cold war. These craft are detected by airspace monitoring and fighter pilots are sent out to pursue them. During world war 2 they were called foo fighters and were common knowledge.

4. There are thousands of photos and videos of UFOs.

5. Entire governments of dozens of countries have declassified tens of thousands of UFO files including hundreds or thousands where natural phenomenon and other mundane explanations have been conclusively ruled out.

6.The disclosure project , with hundreds of credible testimonies from many branches of government, military etc

7. The government official in charge of the official government investigation of the phenomenon, who initially stated that they had concluded there was no reality to the phenomenon, has since come forward and admitted he was part of a cover-up

8. Nasa transmissions that make reference to alien space craft, bogies, UFOs, etc

9. A national security conference was held in Washington DC to discuss the issue of these craft interfering with and disarming nuclear weapons and facilities

10. President Bill Clinton asked the CIA for the ufo/ET files and was denied access. Why would they deny the access to the president if there was not real evidence to deny? In other words, why would they hide it if it was just swamp gas and weather balloons?

There is of course far more than I can summarize or discuss here. But If I had to ask myself what the most compelling evidence I personally have seen (other than extremely convincing and credible accounts from politicians, military officials, Nasa astronauts etc) I would probably point to this particular video.

The whole video is highly interesting , but at 3:45 there is a clip in London, in broad daylight, where dozens of onlookers are watching several craft in the sky that stop, hover in place, reverse direction, accelerate, turn at angles, etc... conclusively showing these are not birds, meteors, or any known human craft or natural phenomenon. Furthermore the same craft are filmed from another location. It is the most compelling video footage I know of.

...

The truth of the matter is that people who deny this phenomenon do so out of

A. ignorance- they simply have not done the research and engaged with the evidence, so they simply do not know

B. Stupidity- They can not understand the evidence, they miss the implications, they fail to see the bigger picture, they cannot connect the dots

C. Denial - They are so uncomfortable with the implications, they will deny it no matter how strong the evidence.

The tides have turned, and denying the presence of extraterrestrials on Earth is, in my opinion, closely akin to those who still believe that the Sun Revolves around the Earth or that the Earth is flat- the old worldview dies hard, especially for the old dogs who simply do not want to learn new tricks.