Eupheme (moon)

Eupheme /juːˈfm/, also Jupiter LX, originally known as S/2003 J 3, is an outer natural satellite of Jupiter, 2 km in diameter.

Eupheme CFHT 2003-02-25 annotated.gif
Images of Eupheme by the Canada-France-Hawaii Telescope in February 2003
Discovered byScott S. Sheppard
Discovery date2003
Jupiter LX
Named after
Ευφήμη Eyphēmē
S/2003 J 3
AdjectivesEuphemean /juːfɪˈmən/[2]
Orbital characteristics[4]
21199710 km
−628.06 days[3]
Satellite ofJupiter
GroupAnanke group
Physical characteristics
Mean diameter
2 km


It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2003.[5][6] The moon was lost following its discovery in 2003.[7][8][9][10] It was recovered in 2017 and given its permanent designation that year.[11]


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 and Aglaea and granddaughter of Zeus.[12] The name was suggested by Twitter 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.[13][14]


Eupheme orbits Jupiter at an average distance of 19,622 Mm in 628.06 days, at an inclination of 146° to the ecliptic (146° to Jupiter's equator), in a retrograde direction and with an eccentricity 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°.


  1. ^ Noah Webster (1884) A Practical Dictionary of the English Language
  2. ^ James Petigru Carson (1920) Life, Letters and Speeches of James Louis Petigru, p. 318
  3. ^ "M.P.C. 106351" (PDF). Minor Planet Circular. Minor Planet Center. May 10, 2017. S/2003 J 3.
  4. ^ S.S. Sheppard (2019), Moons of Jupiter, Carnegie Science, on line
  5. ^ Daniel W. E. Green (March 4, 2003). "IAUC 8087: Satellites of Jupiter". International Astronomical Union.
  6. ^ MPEC 2003-E11: S/2003 J 1, 2003 J 2, 2003 J 3, 2003 J 4, 2003 J 5, 2003 J 6, 2003 J 7 March 4, 2003 (discovery and ephemeris)
  7. ^ Beatty, Kelly (April 4, 2012). "Outer-Planet Moons Found — and Lost". Sky & Telescope. Retrieved June 27, 2017.
  8. ^ Brozović, Marina; Jacobson, Robert A. (March 9, 2017). "The Orbits of Jupiter's Irregular Satellites". The Astronomical Journal. 153 (4): 147. Bibcode:2017AJ....153..147B. doi:10.3847/1538-3881/aa5e4d.
  9. ^ Jacobson, B.; Brozović, M.; Gladman, B.; Alexandersen, M.; Nicholson, P. D.; Veillet, C. (September 28, 2012). "Irregular Satellites of the Outer Planets: Orbital Uncertainties and Astrometric Recoveries in 2009–2011". The Astronomical Journal. 144 (5): 132. Bibcode:2012AJ....144..132J. doi:10.1088/0004-6256/144/5/132. S2CID 123117568.
  10. ^ Sheppard, Scott S. (2017). "New Moons of Jupiter Announced in 2017". Retrieved June 27, 2017. We likely have all of the lost moons in our new observations from 2017, but to link them back to the remaining lost 2003 objects requires more observations a year later to confirm the linkages, which will not happen until early 2018. ... There are likely a few more new moons as well in our 2017 observations, but we need to reobserve them in 2018 to determine which of the discoveries are new and which are lost 2003 moons.
  11. ^ Sheppard, Scott S. (2017). "Jupiter's Known Satellites". Archived from the original on March 18, 2015. Retrieved August 10, 2017.
  12. ^ "Planet and Satellite Names and Discoverers". USGS Astrogeology Science Center. Retrieved August 27, 2019.
  13. ^ "Naming Contest for Newly-discovered Moons of Jupiter". Retrieved August 27, 2019.
  14. ^ "Public Contest Successfully Finds Names For Jupiter's New Moons". Retrieved August 27, 2019.