S/2018 J 2

S/2018 J 2
Discovery
Discovered by	Scott S. Sheppard
Discovery site	Cerro Tololo Obs.
Discovery date	12 May 2018
Orbital characteristics
	Epoch 9 August 2022 (JD 2459800.5)
Observation arc	19.48 yr (7,115 d)
Earliest precovery date	27 March 2003
Semi-major axis	0.0766555 AU (11,467,500 km)
Eccentricity	0.1184102
Orbital period (sidereal)	+250.88 days
Mean anomaly	99.239°
Mean motion	1° 26m 5.896s / day
Inclination	29.40421° (to ecliptic)
Longitude of ascending node	66.06734°
Argument of perihelion	342.09685°
Satellite of	Jupiter
Group	Himalia group
Physical characteristics
Mean diameter	≈3 km
Albedo	0.04 (assumed)
Apparent magnitude	23.3
Absolute magnitude (H)	16.5

S/2018 J 2 is a small outer natural satellite of Jupiter discovered by Scott S. Sheppard on 12 May 2018, using the 4.0-meter Víctor M. Blanco Telescope at Cerro Tololo Observatory, Chile. It was announced by the Minor Planet Center four years later on 20 December 2022, after observations were collected over a long enough time span to confirm the satellite's orbit. The satellite has been found in precovery observations as early as 27 March 2003.^[1]

S/2018 J 2 is part of the Himalia group, a tight cluster of prograde irregular moons of Jupiter that follow similar orbits to Himalia at semi-major axes between 11–12 million km (6.8–7.5 million mi) and inclinations between 26–31°.^[3] With an estimated diameter of 3 km (1.9 mi) for an absolute magnitude of 16.5, it is among the smallest known members of the Himalia group.^[3]

References

^ ^a ^b ^c ^d "MPEC 2022-Y68 : S/2018 J 2". Minor Planet Electronic Circulars. Minor Planet Center. 20 December 2022. Retrieved 20 December 2022.
^ "Planetary Satellite Discovery Circumstances". JPL Solar System Dynamics. NASA. Retrieved 20 December 2022.
^ ^a ^b ^c ^d ^e Sheppard, Scott S. "Moons of Jupiter". Earth & Planets Laboratory. Carnegie Institution for Science. Retrieved 20 December 2022.

This article related to a natural satellite is a stub. You can help Wikipedia by expanding it.

[MPEC-2022-Y68-1] "MPEC 2022-Y68 : S/2018 J 2". Minor Planet Electronic Circulars. Minor Planet Center. 20 December 2022. Retrieved 20 December 2022.

[jplsats-disc-2] "Planetary Satellite Discovery Circumstances". JPL Solar System Dynamics. NASA. Retrieved 20 December 2022.

[SheppardMoons-3] Sheppard, Scott S. "Moons of Jupiter". Earth & Planets Laboratory. Carnegie Institution for Science. Retrieved 20 December 2022.

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v t e Moons of Jupiter
Listed in increasing approximate distance from Jupiter
Inner moons	Metis Adrastea Amalthea Thebe
Galilean moons	Io Europa Ganymede Callisto
Themisto	Themisto
Himalia group (9)	Leda Ersa S/2018 J 2 Himalia Pandia Lysithea Elara S/2011 J 3 Dia
Carpo group (2)	S/2018 J 4 Carpo
Valetudo	Valetudo
Ananke group (26)	Euporie Jupiter LV Eupheme S/2021 J 3 Jupiter LII Jupiter LIV Mneme Euanthe S/2003 J 16 Harpalyke Orthosie S/2022 J 3 Helike S/2021 J 2 Praxidike Jupiter LXIV S/2021 J 1 S/2003 J 12 Jupiter LXVIII Thelxinoe Thyone S/2003 J 2 Ananke Iocaste Hermippe Jupiter LXX
Carme group (30)	S/2022 J 1 S/2022 J 2 S/2016 J 3 Pasithee Jupiter LXIX S/2021 J 6 S/2003 J 24 Chaldene Jupiter LXIII Isonoe S/2021 J 4 Kallichore Erinome Kale Eirene Aitne Eukelade Arche Taygete Jupiter LXXII Carme Herse Jupiter LXI Jupiter LI S/2003 J 9 Jupiter LXVI Kalyke S/2018 J 3 S/2021 J 5 S/2003 J 10
Pasiphae group (18)	Philophrosyne Eurydome Jupiter LVI S/2003 J 4 S/2016 J 4 Jupiter LXVII Hegemone Pasiphae Sponde Megaclite Cyllene Sinope Jupiter LIX Aoede Autonoe Callirrhoe S/2003 J 23 Kore
See also	Rings of Jupiter Jupiter's moons in fiction
Category