I have seen something simmmilar in my own eyes.
It was in a war zone so I first assumed ot was a missile or a shell bit it went over my head, horisontaly, very fast, not more than 200 meters, made no sound, was very bright white even it was mid day in the summer and disapeared after a few kilometers.
All this took less than 5 seconds, and it was about 28 years ago, so I do not expect any alians to land amongst us soon.