S/2021 J 2
Discovery[1]
Discovered byScott S. Sheppard
Discovery siteLas Campanas Obs.
Discovery date12 August 2021
Orbital characteristics[1][2]
Epoch 25 February 2023 (JD 2460000.5)
Observation arc1.06 yr (387 d)
0.1413164 AU (21,140,630 km)
Eccentricity0.3413342
–1.72 yr (–627.96 days)
320.08120°
0° 34m 23.822s / day
Inclination150.11397° (to ecliptic)
340.99094°
71.71210°
Satellite ofJupiter
GroupAnanke group
Physical characteristics
Mean diameter
≈1 km[3]
24.0[3]
17.3[1]

S/2021 J 2 is a small outer natural satellite of Jupiter discovered by Scott S. Sheppard on 12 August 2021, using the 6.5-meter Magellan-Baade Telescope at Las Campanas Observatory, Chile. It was announced by the Minor Planet Center on 19 January 2023, after observations were collected over a long enough time span to confirm the satellite's orbit.[1]

S/2021 J 2 is part of the Ananke group, a cluster of retrograde irregular moons of Jupiter that follow similar orbits to Ananke at semi-major axes between 19–22 million km (12–14 million mi), orbital eccentricities between 0.1–0.4, and inclinations between 139–155°.[3] It has a diameter of about 1 km (0.62 mi) for an absolute magnitude of 17.3, making it one of Jupiter's smallest known moons.[3]

References

  1. ^ a b c d "MPEC 2023-B37 : S/2021 J 2". Minor Planet Electronic Circulars. Minor Planet Center. 19 January 2023. Retrieved 20 January 2023.
  2. ^ "Planetary Satellite Discovery Circumstances". JPL Solar System Dynamics. NASA. Retrieved 10 January 2023.
  3. ^ a b c d Sheppard, Scott S. "Moons of Jupiter". Earth & Planets Laboratory. Carnegie Institution for Science. Retrieved 10 January 2023.


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