![]() S/2003 J 12 imaged by the Canada-France-Hawaii Telescope during follow-up observations in February 2003 | |
Discovery[1] | |
---|---|
Discovered by | Scott S. Sheppard et al. |
Discovery site | Mauna Kea Obs. |
Discovery date | 8 February 2003 |
Orbital characteristics[2] | |
Epoch 17 December 2020 (JD 2459200.5) | |
Observation arc | 9.65 yr (3,525 d) |
Earliest precovery date | 10 December 2001 |
0.1441046 AU (21,557,740 km) | |
Eccentricity | 0.3657005 |
–1.77 yr (–646.64 d) | |
295.36521° | |
0° 33m 24.215s / day | |
Inclination | 154.69036° (to ecliptic) |
127.52296° | |
86.84711° | |
Satellite of | Jupiter |
Group | Ananke group |
Physical characteristics[3] | |
Mean radius | 1.2 km |
Mass | 1.9×1013 kg |
Mean density | 2.6 g/cm3 (assumed) |
Albedo | 0.04 (assumed)[4] |
23.9[4] | |
17.0[2] 16.81±0.19 (R)[3] | |
S/2003 J 12 is a natural satellite of Jupiter, and is one of the smallest known natural satellites in the Solar System. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2003.[5][1]
S/2003 J 12 is about 2.4 km (1.5 mi) in diameter, and orbits Jupiter at an average distance of 21,600 Mm in 647 days, at an inclination of 155° to the ecliptic, in a retrograde direction and with an eccentricity of 0.366.[2] It was initially thought to the innermost of the retrograde satellites of Jupiter, but recovery observations have shown that it is an ordinary member of the Ananke group.[6]
This moon was considered lost[7][8][9][10] until late 2020, when it was recovered in archival CFHT images from 2001-2011 by amateur astronomer Kai Ly.[6] The recovery of the moon was announced by the Minor Planet Center on 13 January 2021.[2]