Gridr (Saturn LIV), originally known as S/2004 S 20, is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, and Jan Kleyna on October 7, 2019 from observations taken between December 12, 2004 and March 22, 2007.[3] It was given its permanent designation in June 2021.[4] On 24 August 2022, it was officially named after Gríðr, a jötunn in Norse mythology.[5] She is the mother of Víðarr the silent and the consort of Odin. She warned Thor about the treachery of Geirröðr and equipped him with her belt of strength, her iron glove, and her staff Gríðarvöl (Gríðr's-staff).[6]
| Discovery[1] | |
|---|---|
| Discovered by | Sheppard et al. |
| Discovery date | 2019 |
| Designations | |
Named after | Gríðr |
| Saturn LIV S/2004 S 20 S2423b[2] | |
| Orbital characteristics[2] | |
| 19211000 km | |
| Eccentricity | 0.204 |
| −990.23 days | |
| Inclination | 163.1° |
| Satellite of | Saturn |
| Group | Norse group |
| Physical characteristics | |
| 4+50% −30% km | |
| 25.0 | |
Gridr is about 4 kilometres in diameter, and orbits Saturn at an average distance of 19.418 Gm in 1010.55 days, at an inclination of 163° to the ecliptic, in a retrograde direction and with an eccentricity of 0.197.[3]
References
edit- ^ Discovery Circumstances from JPL
- ^ a b S.S. Sheppard (2019), Moons of Saturn, Carnegie Science, on line
- ^ a b "MPEC 2019-T126 : S/2004 S 20". minorplanetcenter.net. Retrieved 7 October 2019.
- ^ "M.P.C. 132212" (PDF). Minor Planet Center. International Astronomical Union. 1 June 2021. Retrieved 16 June 2021.
- ^ "Names Approved for 10 Small Satellites of Saturn". usgs.gov. USGS. 24 August 2022. Retrieved 30 August 2022.
- ^ Lindow, John (2002). Norse Mythology: A Guide to Gods, Heroes, Rituals, and Beliefs. Oxford University Press. p. 149. ISBN 978-0-19-983969-8.