Key facts
- Discovered by
- Scott S. Sheppard
- Discovery site
- Cerro Tololo Obs.
- Discovery date
- 11 May 2018
- Designation
- Jupiter LXXI
- Pronunciation
- / ˈ ɜːr s ə /
- Named after
- Ἔρσα Ersa
- Alternative names
- S/2018 J 1
- Observation arc
- 24 years, 2024-12-03 (last obs)
- Earliest precovery date
- 6 August 2000
- Satellite of
- Jupiter
- Group
- Himalia group
- Proper semi major axis
- 11,401,000 km (0.07621 AU ) AU
- Proper inclination
- 29.1° (to ecliptic )
- Proper mean motion
- 527.587231 deg / yr
- Proper orbital period
- 0.68235 yr , (249.229 d )
- Precession of perihelion long
- 8994.503 arcsec / yr
- Precession of asc node
- 4232.058 arcsec / yr
- Mean diameter
- ≈ 3 km
via Wikipedia infobox
Wikidata facts
- Diameter
- 3
- Orbital period
- 252
- Image
- Ersa CFHT precovery 2003-02-24.png
Show 5 more facts
- time of discovery or invention
- 2018-00-00
- orbital eccentricity
- 0.094
- semi-major axis of an orbit
- 11460000
- provisional designation
- S/2018 J 1
- Commons category
- Ersa (moon)
Sources (2)
via Wikidata · CC0
~2 min read
Article
Ersa /ˈɜːrsə/, also designated Jupiter LXXI, is a small outer natural satellite of Jupiter discovered by Scott S. Sheppard on 11 May 2018, using the 4.0-meter Víctor M. Blanco Telescope at Cerro Tololo Observatory, Chile. It was announced alongside nine other Jovian moons on 17 July 2018 and was provisionally designated S/2018 J 1 by the Minor Planet Center, after observations were collected over a long enough time span to confirm the satellite's orbit. The satellite has been found in precovery observations as early as 6 August 2000.
Ersa is part of the Himalia group, a tight cluster of prograde irregular moons of Jupiter that follow similar orbits to Himalia at semi-major axes between 11–12 million km (6.8–7.5 million mi) and inclinations between 26–31°. With an estimated diameter of 3 km (1.9 mi) for an absolute magnitude of 15.9, it is one of the smallest known members of the Himalia group.