An Etymological Dictionary of Astronomy and Astrophysics
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The outermost of Saturn's known satellites, also known as Saturn IX. It is 220 km in diameter and orbits Saturn in 550.5 days at a distance of 12,952,000 km.

In Gk. mythology, Phoebe is the daughter of Uranus and Gaia; grandmother of Apollo and Artemis.

A giant ring around Saturn spanning an area of space from a distance of ~ 128 Saturn equatorial radii, R_S (60,330 km) to 207 R_S, that is, from about 7.7 × 10⁶ to 12.4 × 10⁶ km from the planet. Its vertical thickness is about 40 R_S. The Phoebe ring was detected in 2009 using NASA's infrared → Spitzer Space Telescope. The Phoebe ring is made up mainly of dust particles about 10 to 20 microns in size, or about one-tenth to one-fifth the average width of a human hair. Rocks that are the size of soccer balls or larger with diameters of more than about 20 cm make up no more than about 10 percent of the ring (Verbiscer et al., 2009, Nature, 461, 1098).

→ Phoebe; → ring.