Saw my first UFO last night

[abaris]

Ok, it definitely wasn't the ISS, we've seen that many times from our back yard and what we saw last was much larger and brighter. Also the speed with which it went behind the house next doors roof shows it wasn't at that great an altitude(maybe a couple of thousand feet).

To judge height at night, you would have to have at least some concept of size. And speed may be as deceptive, since you can't possibly be positive of height.