I WAS DRIVING ALONE ON US 25 WHEN I NOTICED A RING OF LIGHT HOVERING ABOVE AN EMPTY FIELD (NO CROPS CURRENTLY BEING CULTIVATED). THE BEST WAY TO DESCRIBE THE LIGHT WAS THAT IT LOOKED LIKE A GIGANTIC FLUORESCENT TUBULAR LIGHT IN THE FORM OF A CIRCLE.IT APPEARED THAT THE LIGHT WAS BEING EMMITED FROM A LARGER SOLID OBJECT ABOVE IT, TO WHICH IT WAS ATTACHED. THE LIGHT WAS HOVERING ABOUT 15 FEET ABOVE THE GROUND, PROBABLY 40 FEET FROM THE HIGHWAY. I SLOWED DOWN TO TAKE IN THIS PROFOUND SIGHT BUT WAS DEEPLY TROUBLED AND DROVE QUICKLY HOME AFTER LESS THAN PROBABLY 30 SECONDS. I WAS HARDLY ABLE TO UTTER TO MY PARENTS WHAT I'D SEEN.