S/2004 S 3

Discovery image of S/2004 S 3
Discovery
Discovered by	Cassini Imaging Science Team
Discovered on	21 June, 2004
Orbital characteristics
Semimajor axis	140,100 − 140,600 km
Eccentricity	< 0.002
Orbital period	0.62 d
Inclination	close to zero
Is a satellite of	Saturn
Physical characteristics
Mean diameter	3-5 km
Rotation period	probably synchronous
Axial tilt	unknown
Albedo	unknown
Atmosphere	none

is the provisional designation of an object seen orbiting Saturn just beyond the outer strand of the F ring on 21 June, 2004. It was discovered by the Cassini Imaging Science Team in images taken by the Cassini-Huygens probe on June 21, 2004, and announced on September 9, 2004.

Despite later attempts to recover it, it has not been reliably sighted since. Notably, an imaging sequence covering an entire orbital period at 4 km resolution taken on 15 November, 2004 failed to recover the object. This suggests that it was a temporary clump of material that had disappeared by that time.

Another object, , was sighted nearby 5 hours later, but this time just inside the F Ring. Because of the differing localisation the second object was given a fresh designation, although their interpretation as a single object on a F-ring crossing orbit is also possible. Such an object might also be orbiting at a slightly different inclination to the F ring, thereby not actually passing through the ring material despite being seen both radially inward and outward of it.

If a solid object after all, would be 3−5 km in diameter based on brightness, and might be a shepherd satellite for the outer edge of Saturn's F ring.

References

External links

• Cassini-Huygens press release about discoveries around the F ring in 2004
• Cassini-Huygens Multimedia: The Clump/Moon Mystery September 5, 2005 (images of the clumps and/or moons seen around the F ring by Cassini cameras)