My family was traveling home, to wyoming, in the early 1990s. we were about half way through the state of south dakota, on i-90, when i saw the wide, pie-shaped object, hovering just above a home on the north side of i-90. i watched the object ascend a very short distance, and move to descend and hover over another home. i was impressed by this large object, larger than the size of the home, being able to hover so close to the rooftop of two homes. i did not report it at the time because i thought i would be ridiculed or dismissed by authorities. i pointed out the object to my husband, who was driving the car, but his main focus was on watching the road in front of him. he did not see the object ascend and descend over the other home. i did, however, tell my sister about it, who thought by my description, that i had seen a ufo. at the time of this siting, the public, to my knowledge, had never seen government aircraft that were shaped like this, and that could hover like this craft did. i was within 500' of this object, but i did not hear any noise. trying to justify what i saw, i thought that maybe it was a secret project the air force was testing. i thought to report this to mufon, once i learned there was an organization like mufon, because i wanted to have mufon possibly provide an explanation of what i saw. i also want to say that this is the only time i have ever experienced anything like this.