I was commuting home, close to 8:55pm mst, & had an intuitive sense to open the moonroof in my acura rdx - specifically to observe the moon, which my son has been tracking for his class studies. when i did, i both saw the moon, as well as a low-flying triangular-shaped object that appeared stationary. i slowed my vehicle, and pulled to the side of the road to observe it. i was almost home & our subdivision is close to both buckley air force base as well as wide open space east of the denver-aurora metro area. at first glance, i believed the object to be one of the many aircraft often sighted over the air force base; however most of those craft fly during daylight hours, & in 13 years in living at this location, i have never observed a craft looking like this one. i observed the triangle-shaped craft hovering, then abruptly moving in an arcing & zigging pattern, low than slightly raising in altitude, in oblique path to buckley air force base for approximately just over a minute. initially i believed it must be an airplane, but after seeing its unusual movements, as well as visually comparing the size of it to other aircraft in the nearby airspace (which there are regularly many - we live about 20 miles south of denver international airport), it became clear to me this was an enormously-sized aircraft compared to other visually observable craft in the night sky. it also moved distinctly differently from anything else i saw tonight - or virtually any night - although in years past i have been witness to other unusual aerial phenomenon (particularly when i lived in boulder county, colorado). the object hovered, changed direction slightly, then arced away at an increasing speed, first south, then accelerating in a north-eastern arc, towards the air force base & dia. as it moved away, i resume following it with my car, finally losing track as it moved too far east for me to observe any longer over the suburban housing subdivision.