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Hiʻiaka
Sign in to saveAlso known as Haumea I, (136108) 2003 EL61 I, S/2005 (2003 EL61) 1, Hi'iaka
natural satellite of the dwarf planet Haumea
Key facts
- Discovered by
- Michael E. Brown Keck Observatory adaptive optics team
- Discovery site
- W. M. Keck Obs. , Mauna Kea
- Discovery date
- 26 January 2005
- Designation
- (136108) Haumea I
- Pronunciation
- / h iː ʔ i ˈ ɑː k ə / , Hawaiian: [ ˈhiʔiˈjɐkə ]
- Named after
- Hiʻiaka
- Alternative names
- S/2005 ( 2003 EL 61 ) 1 , S/2005 (136108) 1
- Semi major axis
- 49 371 ± 45 km
- Eccentricity
- 0.0542 ± 0.0012
- Orbital period sidereal
- 49.462 ± 0.083 d
- Mean anomaly
- 154.53 ° +2.05 ° , −2.00 °
- Inclination
- 77.394° ± 0.038° (to ecliptic ) 1.01° +0.66°, −0.47° (to Haumea's equator) 13.2° ± 0.2° (to Namaka 's orbital plane )
- Longitude of ascending node
- 13.110° +0.030°, −0.031° (to ecliptic )
- Argument of periapsis
- 98.34° +2.02°, −2.06°
- Satellite of
- Haumea
- Dimensions
- 480 × 360 × 286 km ± ( 80 × 60 × 14 km)
- Mean diameter
- 370 ± 20 km ( volume equivalent )
- Mass
- (1.6 ± 0.2) × 10 kg (2025) , (1.2 ± 0.3) × 10 kg (2024)
via Wikipedia infobox
~9 min read
Encyclopedic overview
Hiʻiaka, formal designation (136108) Haumea I, is the larger, outer moon of the trans-Neptunian dwarf planet Haumea. Discovered by Michael E. Brown and the Keck Observatory adaptive optics team on 26 January 2005, it is named after Hiʻiaka, the patron goddess of the Big Island of Hawaii and one of the daughters of Haumea. The moon follows a slightly elliptical orbit around Haumea every 49.5 days, at a distance of 49,400 km (30,700 mi).
Hiʻiaka is an elongated and irregularly shaped body with a mean diameter of 370 km (230 mi), making it the sixth-largest known moon of a trans-Neptunian object. It has a very low bulk density of 0.64 g/cm, which indicates it is mostly made of loosely-packed water ice and rock. Telescope observations have shown that Hiʻiaka has a highly reflective surface made of crystalline water ice, much like Haumea itself. Hiʻiaka rotates about its axis every 9.68 hours. Like its smaller sibling moon Namaka, Hiʻiaka is believed to be a fragment of Haumea that was ejected in the aftermath of a giant impact 4.4 billion years ago.
Excerpted from Wikipedia’s “Hiʻiaka” article, available under the CC BY-SA 4.0 licence.