The craft was very large and designed or cloaked to appear as a very large jet at first glance. but it was too low for a jet and not moving. my first thought was that it was an airliner off course for landing at bush international airport, and that it was too low, and could crash! alarming, until i realized that it wasn't moving. i was driving in a parking lot and had to pay attention to the moving vehicles around me. i glanced at it again, and it clearly had no wings-just a dark stripe amidship, and it had no tail. i had to keep moving, so i glanced away briefly, and when i looked for it again it was miles away, where one would expect a jet landing at bush would be seen. there was a small airplane seemingly near it, moving in the same direction. there are a few small landing fields/airports in the katy area and between katy and bush airport, which is at least 45 minutes by car. i have no further documentation, just a lot of experience seeing ufos and a few encounters/interactions with ets.