I saw a UFO and bc watched it go through a slit in the sky.

Saturday night I went out back with my dogs before bed. As I stepped off back porch and looked up I saw what I thought was an out of place star. Then it started to move slowly it turned a little clockwise. That's when I saw the dim green/blue light. It has a bigger white light. It moved a short distance and went through a slot that was camouflaged like the sky and stars. Then it was just gone. Two years ago on July 4th my son and I saw the same type of UFO much closer. That time it came down from way up extremely fast and rested above the interstate. It had a dim green light. Then its like someone on the object uncovered the light. It did not just turn on. Then the Omaha police helicopter flew in front of it and I saw that it was twice as big as the copter and shaped like a bunch of boxes put together. It then disappeared for15 minutes and reappeared above the first National tower downtown omaha. It covered and uncovered the white light like someone did it with a tarp. It was way to big and fast to be a drone. It then did a bunch of small fast circles and disappeared. My son and I were freaked out! I sent the video of it disappearing to mufon back then and now I don't have it. I wanted to report this just in case I'm taken. Thank you.