Praxidike (moon)


Praxidike imaged by the Canada-France-Hawaii Telescope in December 2001
Discovered byScott S. Sheppard et al.
Discovery siteMauna Kea Obs.
Discovery date23 November 2000
Jupiter XXVII
Named after
Πραξιδίκη Praxidikē
S/2000 J 7
AdjectivesPraxidikean /ˌpræksədəˈkən/[3]
Orbital characteristics[5]
21147000 km
−609.25 days[4]
Satellite ofJupiter
GroupAnanke group
Physical characteristics
Mean diameter
7.0±0.7 km[6]

Praxidike /prækˈsɪdək/, also known as Jupiter XXVII, is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2000,[7][1] and given the temporary designation S/2000 J 7.

It was named in August 2003 after Praxidike,[8] the Greek goddess of punishment.


Praxidike observed by the WISE spacecraft in 2010

Praxidike orbits Jupiter at an average distance of 20,824,000 km in 609.25 days, at an inclination of 144° to the ecliptic (143° to Jupiter's equator), in a retrograde direction and with an eccentricity of 0.1840.

Praxidike belongs to the Ananke group, believed to be the remnants of a break-up of a captured heliocentric asteroid.[9][10] With an estimated diameter of 7 km, Praxidike is the second largest member of the group after Ananke itself (assumed albedo of 0.04).[11]


The satellite appears grey (colour indices B-V=0.77, R-V= 0.34), typical of C-type asteroids.[12]


  1. ^ a b MPEC 2001-A29: S/2000 J 7, S/2000 J 8, S/2000 J 9, S/2000 J 10, S/2000 J 11 January 15, 2001 (discovery and ephemeris)
  2. ^ as 'Praxidice' in Noah Webster (1884) A Practical Dictionary of the English Language
  3. ^ There is also 'Praxidician' /præksəˈdɪʃiən/, as in the 'Praxidician goddesses' that include Praxidice, but this does not derive from the name Praxidice itself.
  4. ^ "M.P.C. 104798" (PDF). Minor Planet Circular. Minor Planet Center. 10 May 2017.
  5. ^ S.S. Sheppard (2019), Moons of Jupiter, Carnegie Science, on line
  6. ^ a b Grav, T.; Bauer, J. M.; Mainzer, A. K.; Masiero, J. R.; Nugent, C. R.; Cutri, R. M.; et al. (August 2015). "NEOWISE: Observations of the Irregular Satellites of Jupiter and Saturn" (PDF). The Astrophysical Journal. 809 (1): 9. Bibcode:2015ApJ...809....3G. doi:10.1088/0004-637X/809/1/3. S2CID 5834661. 3.
  7. ^ IAUC 7555: Satellites of Jupiter January 5, 2001 (discovery)
  8. ^ IAUC 7998: Satellites of Jupiter 2002 October 22 (naming the moon)
  9. ^ Sheppard, S. S., Jewitt, D. C.; An Abundant Population of Small Irregular Satellites Around Jupiter Archived 2003-08-05 at the Wayback Machine, Nature, Vol. 423 (May 2003), pp. 261-263
  10. ^ Nesvorný, D.; Alvarellos, J. L. A.; Dones, L.; and Levison, H. F.; Orbital and Collisional Evolution of the Irregular Satellites, The Astronomical Journal, Vol. 126 (2003), pp. 398–429
  11. ^ Sheppard, S. S.; Jewitt, D. C.; Porco, C.; Jupiter's Outer Satellites and Trojans Archived 2009-09-20 at the Wayback Machine, in Jupiter: The Planet, Satellites and Magnetosphere, edited by Fran Bagenal, Timothy E. Dowling, and William B. McKinnon, Cambridge Planetary Science, Vol. 1, Cambridge, UK: Cambridge University Press, ISBN 0-521-81808-7, 2004, pp. 263-280
  12. ^ Grav, T.; Holman, M. J.; Gladman, B. J.; Aksnes, K.; Photometric Survey of the Irregular Satellites, Icarus, Vol. 166 (2003), pp. 33-45
  1. Ephemeris IAU-MPC NSES
  2. Mean orbital parameters NASA JPL

External links

  • David Jewitt pages
  • Scott Sheppard pages