S/2004 S 3

S/2004 S 3

Discovery image of S/2004 S 3
Discovery
Discovered by	CICLOPS Team
Discovery date	June 21, 2004
Orbital characteristics
Semi-major axis	140,100–140,600 km
Eccentricity	< 0.002
Orbital period	0.62 d
Inclination	close to zero
Satellite of	Saturn
Physical characteristics
Mean radius	1.5–2.5 km
Rotation period	probably synchronous
Axial tilt	unknown
Albedo	unknown

S/2004 S 3 is the provisional designation of an object seen orbiting Saturn just beyond the outer strand of the F ring on June 21, 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 November 15, 2004 failed to recover the object. This suggests that it was a temporary clump of material that had disappeared by that time.

Another object, S/2004 S 4, 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, S/2004 S 3 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

Explanatory

Citations

Sources

• (claiming recovery of S/2004 S 3 on October 17, 2004 in conflict with the later Spitale Jacobson et al. 2006)

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)