Saturn's rings from the inside out: The Cassini Division at left (faint red) is followed by the A ring in its entirety. The A ring begins with a reddish interior, indicating a greater proportion of dirt, followed by more turquoise — ice — at greater distances from the planet. The red band roughly three-fourths of the way outward in the A ring is known as the Encke Gap.
NASA / Univ. Colorado, LASP