Close, BRIGHT, Slow-moving lights seen in Greenwood, SC!!! Absolutely no sound heard!

My son and I were in the car, driving down a road that we often do. I saw very bright lights, that looked like stadium lights, above the trees. I asked my son, "What is that?"  He said, "Lights?"  I said, "Yes, I know that, but where are they coming from?"  When we reached the stop sign, we couldn't see the lights because of the trees.  I was puzzeled but tried not to be alarmed because I knew my son would say I was a nut.  We made a left at the stop sign and then went about a quarter of a mile and turned right. As we made the right, we saw the very big, very bright, slow moving lights. The lights were so bright that we couldn't make out any shape until it crossed the road and we were able to look at it from an angle.  My son exclaimed, "Oh my God! It's a circle!" I was driving and could not take my eyes off of the road for too long. I wanted to stop and turn around but there was a car behind me. We went to the next stop sign and made a left to try to circle aroun! d and find it again- it was so slow moving. But it was gone. We never heard any sound, like you would from an airplane. I have never seen any plane move that slowly. I wish now that I had stopped the car to watch it!