Discovery [1] | |
---|---|
Discovered by | Scott S. Sheppard et al. |
Discovery site | Mauna Kea Obs. |
Discovery date | 5 February 2003 |
Orbital characteristics [2] | |
Epoch 17 December 2020 (JD 2459200.5) | |
Observation arc | 16.42 yr (5,996 d) |
Earliest precovery date | 11 December 2001 |
0.1373976 AU (20,554,390 km) | |
Eccentricity | 0.2776569 |
–1.65 yr (–602.02 d) | |
114.43587° | |
0° 35m 52.742s / day | |
Inclination | 149.20392° (to ecliptic) |
50.46976° | |
224.95527° | |
Satellite of | Jupiter |
Group | Ananke group |
Physical characteristics | |
≈2 km[3] | |
Albedo | 0.04 (assumed)[3] |
23.2[3] | |
16.7[2] | |
S/2003 J 2 is a retrograde irregular satellite of Jupiter. The moon was discovered on 5 February 2003 by a team of astronomers from the University of Hawaii led by Scott S. Sheppard and David C. Jewitt, and was later announced on 4 March 2003.[4][5] It was initially thought to be Jupiter's outermost known moon until recovery observations disproved this in 2020.[6]
S/2003 J 2 is about 2 km (1.2 mi) in diameter, and orbits Jupiter at an average distance of about 20,600,000 kilometers (20.6 gigametres (0.138 AU)) in roughly 600 days, at an inclination of around 149° to the ecliptic and with an eccentricity of 0.28. The moon was initially assumed to be part of the Pasiphae group, but is now known to be part of the Ananke group after it was recovered in 2020.[1][6]
The moon was considered lost[7][8][9][10] until 2020, when it was recovered by Sheppard and independently by amateur astronomer Kai Ly.[6] The recovery of the moon was announced by the Minor Planet Center on 26 January 2021.[2]
MPEC-2021-B134
was invoked but never defined (see the help page).SheppardMoons
was invoked but never defined (see the help page).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.