triangular object with yellow lights hovering in air, along the roadI was traveling south bound on Interstate 35 near Des Moines, IA, and saw a very noticeable light shining on a cellular tower along the interstate. As I became parallel with it I realized it was not moving, it was simply hovering in the air, the object was almost as high as the tower and roughly 100 feet to the south of the tower, I could see a triangular shape with approximately 3 yellow lights and a head/spotlight.I exited off the interstate ¼ mile later to turn around and get a better look. Soon as I got off the exit I looked back and it was gone, I spent the following half hour driving the roads around the area to see if I could see it anywhere, but saw nothing. The time between me exiting off the interstate and turning around to see the object was about 30 seconds.