Kallichore (), also known as Jupiter XLIV and previously as S/2003 J 11, is a small natural satellite or moon of Jupiter. It is one of Jupiter's many irregular moons, which orbit far from the planet on highly inclined and eccentric orbits. Kallichore was discovered by Scott S. Sheppard on 6 February 2003 and was named after Callichore, one of Zeus's daughters in Greek mythology. Kallichore is an elongated object with a diameter of about 4 km (2.5 mi). It orbits Jupiter in the retrograde direction—opposite to the direction of the planet's rotation—at an average distance of 23.0 million km (14.3 million mi). Kallichore shares similar orbital properties as Jupiter's larger irregular moon Carme, which makes it a member of the Carme group. The moons of the Carme group are believed to be fragments of an asteroid or trans-Neptunian object that was gravitationally captured by Jupiter and destroyed by a collision several billion years ago. Kallichore is a potential flyby target for the European Space Agency's Jupiter Icy Moons Explorer (Juice) mission, which is predicted to pass closer than 1 million km (0.62 million mi) from the moon on 7 October 2031. Although it is possible for Juice to come even closer to Kallichore, this possibility remains under investigation as of 2026. Further observations of Kallichore are planned to accurately determine its orbital path before Juice can be directed closer to the moon.
Discovery
Kallichore was discovered by Scott S. Sheppard on 6 February 2003, during a search for distant moons of Jupiter at Mauna Kea Observatory in Hawaii. Conducted in collaboration with David Jewitt, the search involved routine imaging of the sky near Jupiter using various large telescopes equipped with sensitive digital cameras. Sheppard made the discovery observations of Kallichore using the 3.6-meter (12 ft) Canada–France–Hawaii Telescope, while Brian G. Marsden computed the orbit of Kallichore from Sheppard's observational data. The discovery of Kallichore, together with S/2003 J 9, S/2003 J 10, and S/2003 J 12, was announced by the Minor Planet Center and Central Bureau of Astronomical Telegrams on 7 March 2003. Kallichore was one of the 21 Jovian moons announced in 2003, which raised Jupiter's known moon count to 61 in that year.
Name When the discovery of Kallichore was announced, it was given the temporary provisional designation S/2003 J 11. The moon was officially named "Kallichore" with the Roman numeral designation Jupiter XLIV (Jupiter 44) by the International Astronomical Union's (IAU's) Working Group for Planetary System Nomenclature on 30 March 2005. The moon's name comes from Callichore, one of the Muses and one of Zeus's daughters in Greek mythology. The name follows the IAU's naming convention for Jovian moons, which are named after mythological lovers and descendants of Zeus or Jupiter. Since Kallichore has a retrograde orbit, it was given a name ending with the letter "e".
Orbit Kallichore is an irregular moon of Jupiter, meaning it follows a very wide, inclined, and eccentric orbit around the planet. The orbit of Kallichore is retrograde, meaning it orbits in the opposite direction to Jupiter's rotation. The moon orbits Jupiter at an average distance of 23.0 million km (14.3 million mi; 0.154 AU), which places it far beyond the Galilean moons. Like all other irregular moons of Jupiter, Kallichore orbits far enough that its orbit is strongly influenced by gravitational perturbations by the Sun and other giant planets, which causes frequent changes in its orbit. As a result, Kallichore's orbit does not form a closed ellipse. Proper (or mean) orbital elements are often used to describe the general shape and orientation of the orbits of irregular moons like Kallichore. On average, Kallichore has an orbital period of about 714 days (1.95 years) with an orbital eccentricity of 0.259 and an inclination of 164.6° with respect to the ecliptic. Simulations over a 1,000-year timescale show that Kallichore's orbital semi-major axis varies from 22.0 to 24.4 million km (13.7 to 15.2 million mi), while Kallichore's eccentricity and inclination vary from 0.113 to 0.413 and 160.8° to 167.8°, respectively. Kallichore's orbit exhibits nodal and apsidal precession with periods of 86.3 and 49.1 years, respectively. A 2011 study by Julien Frouard and colleagues found that Kallichore's orbit appears to be influenced by a secular resonance involving the nodal and apsidal precession frequencies of itself, Saturn, Uranus, and Neptune.
Group membership and origin
Kallichore shares similar orbital characteristics as Jupiter's large irregular moon Carme, which makes it a member of the Carme group. The moons of the Carme group are believed to be fragments of a larger body that was gravitationally captured by Jupiter and destroyed by a collision several billion years ago. Based on the known colors and compositions of moons from the Carme group, the group's parent body likely originated from the outer Solar System, either as a D-type asteroid from the Hilda or Jupiter trojan populations or from the centaur and trans-Neptunian object populations.
Physical characteristics
… excerpt ends here. Continue reading the full article.
