Praxidike , also known as , is a retrograde irregular satellite of

Jupiter Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a Jupiter mass, mass more than 2.5 times that of all the other planets in the Solar System combined a ...

. It was discovered by a team of

astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...

s from the

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led by Scott S. Sheppard in 2000,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) and given the temporary designation . It was named in August 2003 after Praxidike,IAUC 7998: ''Satellites of Jupiter''
2002 October 22 (naming the moon) the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

goddess A goddess is a female deity. In some faiths, a sacred female figure holds a central place in religious prayer and worship. For example, Shaktism (one of the three major Hinduism, Hindu sects), holds that the ultimate deity, the source of all re ...

punishment Punishment, commonly, is the imposition of an undesirable or unpleasant outcome upon an individual or group, meted out by an authority—in contexts ranging from child discipline to criminal law—as a deterrent to a particular action or beh ...

Orbit

Praxidike

orbit In celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an ...

s Jupiter at an average distance of 20,824,000 km in 609.25

day A day is the time rotation period, period of a full Earth's rotation, rotation of the Earth with respect to the Sun. On average, this is 24 hours (86,400 seconds). As a day passes at a given location it experiences morning, afternoon, evening, ...

s, at an

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Eart ...

of 144° to the

ecliptic The ecliptic or ecliptic plane is the orbital plane of Earth's orbit, Earth around the Sun. It was a central concept in a number of ancient sciences, providing the framework for key measurements in astronomy, astrology and calendar-making. Fr ...

(143° to Jupiter's

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), in a retrograde direction and with an

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of 0.1840. Praxidike belongs to the Ananke group, believed to be the remnants of a break-up of a captured heliocentric asteroid.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 With an estimated diameter of 7 km, Praxidike is the second largest member of the group after Ananke itself (assumed albedo of 0.04).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, , 2004, pp. 263-280

Characteristics

The satellite appears grey ( colour indices B-V=0.77, R-V= 0.34), typical of

C-type asteroid C-type (carbonaceous ) asteroids are the most common variety, forming around 75% of known asteroids. They are volatile-rich and distinguished by a very low albedo because their composition includes a large amount of carbon, in addition to rocks ...

s. Grav, T.; Holman, M. J.; Gladman, B. J.; Aksnes, K.
''Photometric Survey of the Irregular Satellites''
Icarus, Vol. 166 (2003), pp. 33-45

References

* Ephemeri

* Mean orbital parameter
NASA JPL

External links

{{DEFAULTSORT:Praxidike (Moon) Ananke group Moons of Jupiter Irregular satellites Discoveries by Scott S. Sheppard 20001123 Moons with a retrograde orbit