This artists conception shows a nearly invisible ring around Saturn -- the largest of the giant planets many rings. It was discovered by NASAs Spitzer Space Telescope. The ring is so diffuse that it reflects little sunlight, or visible light that we see with our eyes. But its dusty particles shine with infrared light, or heat radiation, that Spitzer can see. The artists conception simulates an infrared view of the giant ring. Saturn appears as just a small dot from outside the band of ice and dust. The bulk of the ring material starts about six million kilometres (3.7 million miles) away from the planet representation.