Hati (moon)
Hati /ˈhɑːti/ or Saturn XLIII is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on 4 May 2005, from observations taken between 12 December 2004 and 11 March 2005.
Hati imaged by the Cassini spacecraft in November 2015 | |
| Discovery | |
|---|---|
| Discovered by | Scott S. Sheppard David C. Jewitt Jan T. Kleyna Brian G. Marsden |
| Discovery date | December 2004 |
| Designations | |
Designation | Saturn XLIII |
Named after | Hati Hróðvitnisson |
Alternative names | S/2004 S 14 |
| Orbital characteristics | |
Semi-major axis | 19697100 km |
| Eccentricity | 0.375 |
Orbital period (sidereal) | −1040.29 days |
| Inclination | 164.1° |
| Satellite of | Saturn |
| Group | Norse group |
| Physical characteristics | |
Mean diameter | 5+50% −30% km |
| Mass | ≥6.5×1013 kg (calculated) |
Mean density | ≥1 g/cm3 |
Synodic rotation period | 5.45±0.04 h |
| Albedo | 0.06 (assumed) |
| 24.4 | |
| 15.3 | |
Hati is about 5 kilometers in diameter, and orbits Saturn at an average distance of 19,697 Mm in 1040 days, at an inclination of 164° to the ecliptic, in a retrograde direction and with an eccentricity of 0.375, somewhat similar to Mundilfari's orbit. In March 2013, the synodic rotational period was measured by Cassini to about 5.45±0.04 hours. This is the fastest known rotation of all of Saturn's moons, and in fact the fastest known among all moons (including asteroid moons) for which a rotation period has been reliably measured. Like Mundilfari, it is very elongated in shape.
It was named in April 2007 after Hati, a giant wolf from Norse mythology, son of Fenrisúlfr and twin brother of Sköll.