Sitting on deck just after returning from picking up dinner. talking with wife while seated facing north. i constantly watch traffic behind house and regular incoming flights to stl lambert international airport. suddenly noticed unusual green light between trees on horizon to the north, roughly the size of a bright star or venus. thought it was incoming aircraft landing lights but after watching for 3-5 seconds, realized it wasn't moving. so, i was curious as to what it was and continued watching. after another 2 seconds i witnessed the green light moved to the west slightly, opposite of normal path of incoming flights. i thought maybe it was a helicopter. still curious though, i kept watching and saw the light turn from green to red, then back to green, as if the object was rotating, while it was moving west from the original hovering position. as it returned to the green light, it dipped slightly on the horizon, then rose back to its original altitude, hovered for 1 second, then ascended a couple degrees. at this point i knew i was witnessing something very unusual and got chills. after ascending, the light moved west again about the length of your index finger held at arms length. without stopping, the light descended immediately from the westward direction and disappeared behind the tree line at the top of my subdivision. i waited 20 minutes for the object to reappear, but did not see anything again. based on helicopters and planes regularly seen in the area for last decade, i estimate distance of like-sized object with similar lights to be between 5-10 miles north of my location. if the object was larger, it was most certainly farther away and its movements much faster than normal craft. i am reporting this today to help corroborate any other witnesses since it happened on a friday evening near a major interstate interchange in sight of anyone traveling north on i-64 near i-70.