Round metallic jellyfish-like craft with white blinking lights flies over car low & slow, Columbia, SC

I was driving West on Rt. I-26 and was near exit 104 (Piney Grove) when I saw what I thought was a low flying plane headed East, almost directly over the road but slightly South of the road.  It was dark outside and the craft had several white lights (4?) underneath that blinked on and off about every 1 or 1.5 seconds.  It was flying very low and slow and as it approached and flew overhead I looked up twice and saw that it was circular in shape. I thought perhaps it was foggy outside and that the glow from the lights made the craft appear circular (it had been very foggy on a prior night, but it actually was clear this night). I am not sure if it generated any sound as I had the radio on, but certainly there was no loud engine sound.  I wanted to turn around to follow the craft, but I had just passed an exit.  I thought it had the shape of a sort of metallic jellyfish but without any tendrils.   I could not locate any media accounts of this sighting, so maybe i! t was a plane after all.