Carpo (moon)

Infobox Planet
name = Carpo
bgcolour = #ffc0c0
discovery = yes
discoverer = Scott S. Sheppard "et al."
discovered = 2003
mean_orbit_radius = 17.145 million km
period = 458.625 days
inclination = 56° to the ecliptic
eccentricity = 0.4316cite web
date=2007-Jun-28
title=Planetary Satellite Mean Orbital Parameters
publisher=JPL/NASA
author=Jacobson, R.A. (2006) JUP262
url=http://ssd.jpl.nasa.gov/?sat_elem#jupiter
accessdate=2008-01-19]
physical_characteristics = yes
mean_radius = ~1.5km

Carpo (pron-en|ˈkɑrpoʊ "KAR-poh," or as in Greek "Καρπώ)," also nowrap|Jupiter XLVI, is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2003, and was provisionally designated as nowrap|S/2003 J 20 [ [http://cfa-www.harvard.edu/iauc/08100/08125.html IAUC 8125: "S/2003 J 19 and S/2003 J 20"] 2003 April 30 (discovery)] [ [http://cfa-www.harvard.edu/mpec/K03/K03G67.html MPEC 2003-G67: "S/2003 J 20"] 2003 April 14 (discovery and ephemeris)] until it received its name in early 2005. [ [http://cfa-www.harvard.edu/iauc/08500/08502.html IAUC 8502: "Satellites of Jupiter"] 2005 March 30 (naming the moon)]

Carpo is about 3 kilometres in diameter, and orbits Jupiter at an average distance of 17,145 Mm in 458.625 days, at an inclination of 56° to the ecliptic (55° to Jupiter's equator), and with a high eccentricity of 0.4316. All of the moons further from Jupiter than Carpo are retrograde.

It was named in March 2005 after Carpo, one of the Horae, and a daughter of Zeus (Jupiter).

Like Themisto, this moon seems to be the lone member of a unique class, which makes it particularly interesting. The orbital inclination of satellites such as this one is limited by the Kozai effect, discovered by Yoshihide Kozai in 1962. This effect induces a periodic exchange between the inclination and eccentricity of the orbit; if the inclination is large enough, the eccentricity can in turn grow so large that the periapsis of the satellite (called the "perizene" in the case of moons of Jupiter) would be in the immediate vicinity of the Galilean moons (Io, Europa, Ganymede and Callisto). The satellite would eventually collide with one of these, or a close encounter would eject it altogether from the Jovian system. The periapsis precession period (P_w) is 6.8 million years long.

References

External links

* [http://www.dtm.ciw.edu/sheppard/satellites/jupsatdata.html Jupiter's Known Satellites] (by Scott S. Sheppard)