Eupheme , also Jupiter LX, originally known as , is an outer

natural satellite A natural satellite is, in the most common usage, an astronomical body that orbits a planet, dwarf planet, or small Solar System body (or sometimes another natural satellite). Natural satellites are often colloquially referred to as ''moons'' ...

Jupiter Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousandth t ...

, 2 km in diameter.

Discovery

It was discovered by a team of astronomers from the

University of Hawaii A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, th ...

led by

Scott S. Sheppard Scott Sander Sheppard (born 1977) is an American astronomer and a discoverer of numerous moons, comets and minor planets in the outer Solar System. He is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Scie ...

in 2003. The moon was

lost Lost may refer to getting lost, or to: Geography *Lost, Aberdeenshire, a hamlet in Scotland * Lake Okeechobee Scenic Trail, or LOST, a hiking and cycling trail in Florida, US History *Abbreviation of lost work, any work which is known to have bee ...

following its discovery in 2003. It was recovered in 2017 and given its permanent designation that year.

Name

It was named in 2019 after Eupheme, the ancient Greek spirit of words of good omen, praise, acclaims, shouts of triumph, and applause, the daughter of

Hephaestus Hephaestus (; eight spellings; grc-gre, Ἥφαιστος, Hḗphaistos) is the Greek god of blacksmiths, metalworking, carpenters, craftsmen, artisans, sculptors, metallurgy, fire (compare, however, with Hestia), and volcanoes.Walter B ...

and

Aglaea Aglaea () or Aglaïa (; grc, Ἀγλαΐα, lit=festive radiance) is one of the three ''Charites'' or ''Gratiae'' (Graces) in Greek mythology. Family According to Hesiod, Aglaea is the youngest of the Charites, the three daughters of Zeus a ...

and granddaughter of

Zeus Zeus or , , ; grc, Δῐός, ''Diós'', label= genitive Boeotian Aeolic and Laconian grc-dor, Δεύς, Deús ; grc, Δέος, ''Déos'', label= genitive el, Δίας, ''Días'' () is the sky and thunder god in ancient Greek reli ...

. The name was suggested by

Twitter Twitter is an online social media and social networking service owned and operated by American company Twitter, Inc., on which users post and interact with 280-character-long messages known as "tweets". Registered users can post, like, and ...

user Lunartic (@iamalunartic) in a naming contest held by the Carnegie Institute on the social network who concurrently helped in naming another Jovian moon

Philophrosyne Philophrosyne was the ancient Greek female spirit of welcome, friendliness, and kindness. Her sisters were Euthenia, Eupheme, and Eucleia. Along with her sisters, she was regarded as a member of the younger Charites. According to the Orphic fr ...

Orbit

Eupheme orbits Jupiter at an average distance of 19,622 Mm in 628.06 days, 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 146° to the

ecliptic The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic agains ...

(146° to Jupiter's equator), in a retrograde direction and with an

eccentricity Eccentricity or eccentric may refer to: * Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal" Mathematics, science and technology Mathematics * Off-Centre (geometry), center, in geometry * Eccentricity (g ...

of 0.2507. It belongs to the Ananke group, retrograde irregular moons that orbit Jupiter between 19.3 and 22.7 Gm, at inclinations of roughly 150°.

References

{{DEFAULTSORT:Eupheme (Moon) Ananke group Moons of Jupiter Irregular satellites Astronomical objects discovered in 2003 Discoveries by Scott S. Sheppard Moons with a retrograde orbit