S/2003 J 2

S/2003 J 2 is a retrograde irregular satellite of Jupiter. The discovery, by a team of astronomers from the University of Hawaii led by Scott S. Sheppard and David C. Jewitt, was announced on March 4, 2003.[2][3] It is Jupiter's outermost known moon as of 2019.

S/2003 J 2

Discovery
Discovered by	University of Hawaiʻi team led by Scott S. Sheppard and David C. Jewitt
Discovery date	2003 March 4
Orbital characteristics [1]
Semi-major axis	28570410 km
Eccentricity	0.380
Orbital period	−982.5 days (2.69 Earth years)
Average orbital speed	2.19 km/s (calculated)
Inclination	154° (to the ecliptic) 151.8° (to Jupiter's equator)
Satellite of	Jupiter
Group	Pasiphae group?
Physical characteristics
Mean diameter	2 km
Apparent magnitude	23.2

S/2003 J 2 is about 2 km (1.2 mi) in diameter, and orbits Jupiter at an average distance of 29,545,579.5 kilometers (29.54 gigametres (0.1975 AU)) in 981.55 days, at an inclination of 154° to the ecliptic (152° to Jupiter's equator) and with an eccentricity of 0.4100.[4][5][6]

It may belong to the Pasiphae group, though its orbit is not known well enough to confirm the assignment. Its orbit has a semi-major axis ~30 gigametres (0.20 AU) and inclination ~160°.[5]

The limits of Jupiter's gravitational influence are defined by its Hill sphere, whose radius is 52 gigametres (0.35 AU). Retrograde moons with semi-major axes up to 67% of the Hill radius are believed to be stable. Consequently, it is possible that even more distant moons of Jupiter may be discovered.

This moon has not been seen since its discovery in 2003 and is currently considered lost.[7][8][9][10]

References

1. S.S. Sheppard (2019), Moons of Jupiter, Carnegie Science, on line
2. IAUC 8087: Satellites of Jupiter 2003 March 4 (discovery)
3. Sheppard, Scott S.; Jewitt, David C. (2003). "An abundant population of small irregular satellites around Jupiter" (PDF). Nature. 423 (6937): 261–263. Bibcode:2003Natur.423..261S. doi:10.1038/nature01584. PMID 12748634. Archived from the original (PDF) on May 15, 2006.
4. MPEC 2003-E11: S/2003 J 1, 2003 J 2, 2003 J 3, 2003 J 4, 2003 J 5, 2003 J 6, 2003 J 7 2003 March 4 (discovery and ephemeris)
5. Mean orbital elements from NASA JPL (August 2006)
6. Current (2004 July 14, JD= 2453200.5) orbital elements as reported by IAU-MPC NSES are a= 0.2024818 AU, e=0.1882469 i=153.52114
7. Beatty, Kelly (4 April 2012). "Outer-Planet Moons Found — and Lost". www.skyandtelescope.com. Sky & Telescope. Retrieved 27 June 2017.
8. Brozović, Marina; Jacobson, Robert A. (9 March 2017). "The Orbits of Jupiter's Irregular Satellites". The Astronomical Journal. 153 (4): 147. Bibcode:2017AJ....153..147B. doi:10.3847/1538-3881/aa5e4d.
9. Jacobson, B.; Brozović, M.; Gladman, B.; Alexandersen, M.; Nicholson, P. D.; Veillet, C. (28 September 2012). "Irregular Satellites of the Outer Planets: Orbital Uncertainties and Astrometric Recoveries in 2009–2011". The Astronomical Journal. 144 (5): 132. Bibcode:2012AJ....144..132J. doi:10.1088/0004-6256/144/5/132.
10. Sheppard, Scott S. (2017). "New Moons of Jupiter Announced in 2017". home.dtm.ciw.edu. Retrieved 27 June 2017. We likely have all of the lost moons in our new observations from 2017, but to link them back to the remaining lost 2003 objects requires more observations a year later to confirm the linkages, which will not happen until early 2018. ... There are likely a few more new moons as well in our 2017 observations, but we need to reobserve them in 2018 to determine which of the discoveries are new and which are lost 2003 moons.