Jupiter's New Moons

Jupiter XVII, XVIII, ...?


   Nearly two dozen small irregular jovian satellites have been discovered recently. Many new moons of Saturn and Uranus are also showing up.

   Callirrhoe (S/1999 J1) was discovered by the Spacewatch project and the Minor Planet Center in 2000 from images taken in 1999.

   Observations with the VLT in July 2000 confirmed the existence of S/1999 J1 and refined our knowledge of its size and orbit.

   Names for the first 11 of these new moons were assigned by the IAU in Oct 2002.

   We usually say that these irregular satellites are "captured asteroids". But the mechanism of their capture is unclear. The truth is we don't really know how they came to be where they are.

Preliminary Data

IAU Name Distance Period Inclination Eccentricity Brightness Radius Discoverer Date aka
  [x1000 km] [days] [degrees]   [magnitudes]        
Callisto 1883 17 0 0.01 5.6 2403 Galileo 1610  
Themisto 7435 130 46 0.20 21 4 Sheppard et al 2000 S/1975 J1; S/2000 J1
Leda 11094 239 27 0.15 20.2 8 Kowal 1974  
Himalia 11480 251 28 0.16 15 93 Perrine 1904  
Lysithea 11720 259 29 0.11 18.2 18 Nicholson 1938  
Elara 11737 260 28 0.21 16.6 38 Perrine 1905  
S/2000 J11 12654 290 29 0.22 22.4 2 Sheppard et al 2000  
S/2001 J10 19017 534 147 0.16 23.1 1 Sheppard et al 2002 a543509
Chaldene 20375 591 166 0.16 22.5 1.9 Sheppard et al 2000 S/2000 J10
Iocaste 20733 605 150 0.27 21.8 2.6 Sheppard et al 2000 S/2000 J3
S/2001 J8 20804 609 165 0.48 23 1 Sheppard et al 2002 a503602
S/2001 J9 20876 617 142 0.27 23.1 1 Sheppard et al 2002 a542908
S/2001 J2 20876 615 149 0.30 22.3 2 Sheppard et al 2002 a543208
S/2001 J7 20947 622 146 0.18 22.8 1.5 Sheppard et al 2002 a543107
Harpalyke 21019 618 149 0.20 22.2 2.2 Sheppard et al 2000 S/2000 J5
Praxidike 21162 626 146 0.15 21.2 3.4 Sheppard et al 2000 S/2000 J7
Ananke 21200 631 147 0.17 18.9 15 Nicholson 1951  
S/2001 J3 21376 630 150 0.25 22.1 2 Sheppard et al 2002 a506111
Taygete 21734 652 164 0.25 21.9 2.5 Sheppard et al 2000 S/2000 J9
Erinome 21948 661 161 0.35 22.8 1.6 Sheppard et al 2000 S/2000 J4
Carme 22600 692 163 0.21 17.9 20 Nicholson 1938  
Isonoe 22806 704 165 0.28 22.5 1.9 Sheppard et al 2000 S/2000 J6
S/2001 J6 22949 715 165 0.29 23.2 1 Sheppard et al 2002 a543104
S/2001 J4 23378 713 150 0.35 22.7 1.5 Sheppard et al 2002 a506111b
S/2001 J11 23449 736 166 0.29 22.7 1.5 Sheppard et al 2002 a506406
Pasiphae 23500 735 147 0.38 16.9 25 Melotte 1908  
Megaclite 23521 733 152 0.53 21.7 2.7 Sheppard et al 2000 S/2000 J8
S/2001 J5 23592 732 155 0.45 23 1 Sheppard et al 2002 a506601
Sinope 23700 758 153 0.28 18 18 Nicholson 1914  
S/2001 J1 23878 753 152 0.42 22 2 Sheppard et al 2002 a527405
Kalyke 24164 766 166 0.32 21.8 2.6 Sheppard et al 2000 S/2000 J2
Callirrhoe 774 143   0.13   2.4 Spacewatch 1999 S/1999 J1; 1999 UX18

The above is not accurate; JPL has the definitive numbers. More names will be assigned later.

More about these moons

Open Issues

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Bill Arnett; last updated: 2002 Oct 25