Ersa (moon)


Ersa /ˈɜːrsə/, also Jupiter LXXI, originally known as S/2018 J 1, is an outer natural satellite of Jupiter. It was discovered by Scott S. Sheppard and his team on 11 May 2018, and was later announced on 17 July 2018, via a Minor Planet Electronic Circular from the Minor Planet Center.[2] It is about 3 kilometres (2 mi) in diameter and has an orbit radius of around 11,483,000 kilometres (7,135,000 miles); its orbital inclination is about 30.61°.[3] It belongs to the Himalia group.

Ersa CFHT precovery 2003-02-24.png
Precovery image of Ersa taken by the Canada-France-Hawaii Telescope in February 2003
Discovered byScott S. Sheppard et al.
Discovery date11 May 2018
Jupiter LXXI
Named after
Ἔρσα Ersa
S/2018 J 1
Orbital characteristics[1]
11483000 km
+252.0 days
Satellite ofJupiter
GroupHimalia group
Physical characteristics
Mean diameter
3 km


Precovery images of Ersa by the CFHT on 24 February 2003

The moon was named in 2019 after Ersa, the Greek goddess of dew, daughter of Zeus and Selene: Jupiter L Herse is also named for this goddess.[4] The name was suggested in a naming contest held by the Carnegie Institute on Twitter, where more than twenty tweets suggested the name, including Aaron Quah (@8603103) who submitted the name first, StSauveur_MoonsProject (@StSauMoons) that are the 12th grade students of Saint Sauveur High School in Redon, France, the fifth grade at Hillside Traditional Academy in British Columbia, Canada (submitted on their behalf by @mrgrouchypants), and a 4-year-old child who sang a song about Ersa (submitted on his behalf by @Thoreson).[5][6]


  1. ^ S.S. Sheppard (2019), Moons of Jupiter, Carnegie Science, on line
  2. ^ "MPEC 2018-O18 : S/2018 J 1". Minor Planet Center. International Astronomical Union. Retrieved 17 July 2018.
  3. ^ Sheppard, Scott S. "JupiterMoons". Retrieved 18 July 2018.
  4. ^ "Planetary Names: Planet and Satellite Names and Discoverers".
  5. ^ "Naming Contest for Newly-discovered Moons of Jupiter". Retrieved 27 August 2019.
  6. ^ "Public Contest Successfully Finds Names For Jupiter's New Moons". Retrieved 27 August 2019.