This one is just going to be entirely about aliens.
The major part of it is going to have to wait, but I can very quickly share a personal story of my first impression that there was something out there.
When I was sixteen or seventeen, I was laying in a field with a friend, watching the stars, and I saw something unexplainable.
From two sides of the horizon, I saw two small red circles in the sky, moving very fast from one end of the sky to the other.
It was apparent after a couple seconds of watching them that they were on a collision course, since they were about 30 degrees apart, each on a linear trajectory towards the same point in the sky. Long enough for me to wonder, “I wonder what will happen when they meet?”
Well, they were moving so fast, that they quickly overlapped in the sky almost, but not quite directly, overhead. Nothing happened when they crossed paths, except that it became obvious that they were both the same size, and circular, and they formed one faint, red circle for a brief moment. Then they just continued to move to the opposite ends of the horizon from where they began. I think the whole thing lasted between 8 and 10 seconds. I have no idea at what altitude they might have been, but they seemed to be at least cruising altitude of a passenger flight. I had no idea then, but if I had to guess now, I would say they were moving about 4-5 times as fast as a fast jet, so maybe between 800-2000 miles per hour. Then again, the farther up the lights were, the faster they would have been moving, to cross the same amount of sky in the same time. They could have been much higher up, and moving much more quickly.
That was the first thing.