Valetudo (moon)

Lore & Background

Valetudo was discovered by Scott S. Sheppard and his team in data acquired by the 6.5-m Magellan-Baade telescope of the Las Campanas Observatory in 2016, but was not announced until 17 July 2018, via a Minor Planet Electronic Circular from the Minor Planet Center, which also reported the discovery of nine other of Jupiter's moons. Besides data from Las Campanas, the original announcement also referred to data acquired through the 8.1-m Gemini North telescope of the Mauna Kea Observatories as well as the 4.0-m reflector of the Cerro Tololo Inter-American Observatory.

Valetudo has a diameter of about 1 km and orbits Jupiter at a distance of about 19 million kilometres. Its orbital inclination is 34 degrees, and its orbital eccentricity is 0.222. It has a prograde orbit which takes almost a year and a half to complete, but it crosses paths with several other moons that have retrograde orbits and may in the future collide with them.

The moon was provisionally designated as S/2016 J 2 until it received its name in 2018. Sheppard proposed the name Valetudo, after the Roman goddess of health and hygiene and a great-granddaughter of the god Jupiter. The name also alluded to Sheppard's girlfriend, whom he joked about being cleanly. The name conforms with the naming conventions for Jupiter moons set out by the IAU, according to which a name ending in -o indicates a high inclination. The name was approved by the IAU Working Group for Planetary System Nomenclature on 3 October 2018.

Reader's Guide

Valetudo's significance lies in its unusual prograde orbit among a swarm of retrograde moons, making it a potential future collision hazard. Discovered in 2016 but announced in 2018 alongside nine other Jovian moons, it was identified using multiple observatories: the Magellan-Baade telescope, Gemini North telescope, and the Cerro Tololo reflector. Its small size—about 1 km in diameter—and distant orbit at roughly 19 million kilometres from Jupiter place it among the irregular moons. The naming process reflects IAU conventions: the ending -o denotes high inclination, and the name Valetudo, proposed by Sheppard, honors the Roman goddess of health and hygiene, with a personal nod to his girlfriend. The moon's orbital eccentricity of 0.222 and inclination of 34 degrees, combined with its prograde motion crossing retrograde orbits, underscore the dynamic and potentially unstable environment of Jupiter's outer moon system.

Did You Know?

• Valetudo was discovered in 2016 but not announced until 17 July 2018.
• It has a prograde orbit that crosses paths with several retrograde moons, risking future collision.
• The name Valetudo was proposed by Scott S. Sheppard and alludes to his girlfriend, whom he joked about being cleanly.