Praxidike (// prak-SID-ik-ee; Greek: Πραξιδίκη), 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, and given the temporary designation S/2000 J 7.
Praxidike orbits Jupiter at an average distance of 20,824 Mm in 613.904 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. With an estimated diameter of 7 km, Praxidike is the second largest member of the group after Ananke itself (assumed albedo of 0.04).
- IAUC 7555: Satellites of Jupiter January 5, 2001 (discovery)
- 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)
- IAUC 7998: Satellites of Jupiter 2002 October 22 (naming the moon)
- Sheppard, S. S., Jewitt, D. C.; An Abundant Population of Small Irregular Satellites Around Jupiter, Nature, Vol. 423 (May 2003), pp. 261-263
- 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
- Sheppard, S. S.; Jewitt, D. C.; Porco, C.; Jupiter's Outer Satellites and Trojans, 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
- Grav, T.; Holman, M. J.; Gladman, B. J.; Aksnes, K.; Photometric Survey of the Irregular Satellites, Icarus, Vol. 166 (2003), pp. 33-45