Blue disk like fire ball appeared in the sky, Flew downwards into the sky and disappeared instantly.

I woke up in the middle of the night, and went downstairs with my dog. I have large windows and I had them opened, as I was watching the sky a Blue disk appeared instantly in the sky and floated momentarily, once I looked at it for a second, it flew into the sky faster than anything I have ever seen. It almost looked like a comet but it did not move like a shooting star. There is military craft that is trained near us, but this was almost your stereotypical flying saucer, it just did not stay at all, and moved as fast as the speed of light (299 792 458 meters / second, not metaphorically.).
Today this morning there are Jet Streams in an X shape in the same sky line as well as some clouds, I'm not sure if its related but somewhat interesting.