I was sitting on my porch in denver, just south of the city with two friends looking at the stars, when i saw it. it had to have been at least 50,000 feet in the air, but was absolutely massive. it was a perfect triangle that had five "lights" on the bottom of the craft in a "v" formation. it was completely silent but moving at about the speed of a satellite (clearly way faster than a jet). i watched it move from one side of the sky to the other before it became too hard to see. it really looked as if the craft was cloaked, or maybe even in space and i was just seeing the atmospheric distortion. if it was in space, then it must have been the size of a few city blocks. i can't imagine anyone would be able to see this unless their eyes fell upon the exact spot it was in since it was so dim and far away. my two friends standing next to me couldn't get a visual even though i was pointing right at it.