The tiny moon, which is about 5 miles across, displaces that material as it charges, clearing out a space called the Keeler Gap
. Its gravity also kicks up waves in the dust on the edges of the gap.
Daphnis clears the 26-mile-wide (42-km) Keeler Gap
. It has collected a ridge-like pileup of dust around its equator, and its gravity raises waves in the gap's edges.
Such is the case for a tiny moon that Cassini has now spotted in the Keeler gap, which lies just inside the outer edge of Saturn's A ring.
NEW MOON--The Cassini spacecraft recently confirmed the existence of a 7-kilometer-wide moon, provisionally named S/2005 S1 (arrow), in a section of the outer part of the A ring known as the Keeler gap. The moon sculpts the scalloped edges at the gap's boundaries.
Two moons, each several kilometers wide, orbit inside gaps in the outer A ring: Pan in the 320-km-wide Encke Division and Daphnis in the 35-km-wide Keeler Gap
. Much as planetesimals must do in a disk around a young star, Pan and Daphnis gravitationally perturb the orbits of the smaller ring particles that pass by them, creating scalloped patterns in the gap edges and generating wakes that propagate into the ring.
Although the moon is only 7 kilometers across, it has enough gravity to scallop the edges of what's known as the Keeler gap
in the A ring, the outermost of the planet's bright main rings.
The Cassini spacecraft has also chalked up a new Saturnian moon, a world just 7 km across that orbits within the Keeler Gap
in Saturn's outer A ring.
Adding insult to injury, the name Keeler Gap
has been assigned to a division only 35 km wide located 270 km inside the outer edge of ring A--a feature that Keeler never saw and that is beyond the grasp of any ground-based telescope.
If these structures were to grow several hundred times they would wrap around and form ring gaps the way Pan and Daphnis carve the Encke and Keeler gaps