Kallichore is ∼3 kilometers in size and thus one of the small known Irregular moons of Jupiter. It has been discovered with the Canada-France-Hawai’i Telescope on Mauna Kea in February 2003 by a group of astronomers led by S. Sheppard; the discovery announcement followed in March 2003 joint with 20 other outer Jovian moons. The mean distance of Kallichore to Jupiter is ∼23.0 million kilometers, with one revolution around the planet on a retrograde orbit requiring 1 year, 8 months and 2 weeks (from “full-moon” to “full-moon”) or almost exactly 2 years (sidereal period; as seen from Jupiter). It is a member of the Carme group, made up of Irregular moons orbiting Jupiter retrogradely at a distance ranging between ~22.7 and ~23.6 million kilometers and at an inclination to the ecliptic of about 165° .
In early October 2031, the 🛰️ Juice spacecraft of the European Space Agency (ESA) will come closer than 0.6 million kilometers to Kallichore. This will be the closest approach of Juice to any Irregular Jovian moon. An alternate path of the first orbit might bring Juice as close as 153,000 km to this little moon, and even a close targeted flyby appears possible at low fuel cost. This is currently under investigation.
On 30 Nov and 05 Dec 2025, Kallichore has been observed with the WFC3 camera of the Hubble Space Telescope (GO/DD 18215) at a spatial resolution of 125 kilometers per pixel and a Solar-phase angle of ~8°. For an animated-gif of the 16 images, see →here. Goal of the observations was to improve astrometry in general, and in particular to narrow down the uncertainty of the path of a stellar occultation on 15 Dec 2025 over Türkiye, Europe and the US.
Last update: 17 Dec 2025 — page content is best displayed on a screen at least 1024 pixels wide
© Tilmann Denk (2025)