Triangular object, white lights, silent but incredibly fast.

I was checking the lights on my roof when I noticed three white triangular lights shoot across the sky, west to east, from Cheyenne Mountain out towards Peyton/Calhan way.
 The motion was fast and low, somewhat sweeping; too fast for an aircraft as it was completely silent. Speed was slower than a shooting star but faster than jet aircraft. Being as low as it was an aircraft would have created a boom; we see jets daily here. It literally disappeared, no change in altitude, only a slight curve in trajectory and then it was gone.
 I have been running it through my head for an hour and I cannot logically explain it.