Keeping Things in Check

From just outside the faint edge of Saturn's F ring, the moon Pandora keeps watch over her fine-grained flock. The outer flanks of the F ring region are populated by ice particles approaching the size of the particles comprising smoke. As a shepherd moon, Pandora helps her cohort Prometheus confine and shape the main F ring. Pandora is 84 kilometers (52 miles) across.

Prometheus is 102 kilometers (63 miles) wide and orbits interior to the F ring.

The small knot seen attached to the core is one of several that Cassini scientists are eyeing as they attempt to distinguish embedded moons from transient clumps of material (see PIA07716).

The image was taken with the Cassini spacecraft narrow-angle camera on Aug. 2, 2005, using a filter sensitive to wavelengths of infrared light centered at 930 nanometers at a distance of approximately 610,000 kilometers (379,000 miles) from Pandora and at a Sun-Pandora-spacecraft, or phase, angle of 146 degrees. Image scale is 4 kilometers (2 miles) per pixel.

http://photojournal.jpl.nasa.gov/catalog/PIA07579