I was walking home from my friend's house i happened to look up at the sky and saw this solid mass south-southeast from the direction i was walking, a plane had taken off from glasgow international i'd say about 2 minutes into flight (around 10-15k ft) this thing was hovering well above the plane, (it actually dwarfed the plane by some margin) it was solid colour silver it was absolutely masssive and i'm sure it wasn't the iss, 1 the iss wasn't in the airspace at that time and 2, it was way bigger than the iss. i observed it whilst walkibng then trees blocked my vision, by the time i got past the trees the thing had gone. i don't know if it landed (if it had i would have heard something about it) or went somewhere else. (it was out of my view for arounf 30 seconds)