Ymir (moon)

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Ymir
Discovery[1]
Discovered by Brett J. Gladman
Discovery site Observatoire de la Cote d'Azur
Discovery date 2000
Designations
Alternative names S/2000 S1
Adjective Ymirian
Orbital characteristics[2]
Semi-major axis 23,040,000 km
Eccentricity 0.3349
Orbital period 3.6 yr (1315.14 d)
Mean anomaly 244.521°
Inclination 173.125°
Longitude of ascending node 194.086°
Argument of perihelion 22.668°
Satellite of Saturn
Physical characteristics
Dimensions 18 km[3]
Mass 5.1×1015 kg[4]
Escape velocity 8.7 m/s (31 km/h)[4]
Rotation period 11 h 55 m 20 s[5]
Albedo 0.06[6]
Apparent magnitude 21.7[3]

Ymir (/ˈɪmɪər/ IM-eer), or Saturn XIX, is a retrograde irregular moon of Saturn. It was discovered by Brett J. Gladman, et al. in 2000, and given the temporary designation S/2000 S 1. It was named in August 2003, from Norse mythology, where Ymir is the ancestor of all the Jotuns or frost giants.[7]

Of the moons that take more than 3 Earth years to orbit Saturn, Ymir is the largest, at about 18 kilometres (11 miles) in diameter.[3] It takes 3.6 Earth years to complete an orbit around Saturn. During this time, hypothetical Ymir visitors would experience ~2650 sunsets.

References[edit]

  1. ^ Brian G. Marsden (2000-10-25). "IAUC 7512". IAU. Retrieved 2011-01-08. 
  2. ^ Jacobson, R.A. (2007) SAT270, SAT271 (2007-06-28). "Planetary Satellite Mean Orbital Parameters". JPL/NASA. Retrieved 2008-02-14. 
  3. ^ a b c Scott S. Sheppard. "Saturn's Known Satellites". Department of Terrestrial Magnetism. Retrieved 2008-02-14. 
  4. ^ a b assume radius of 9 km; volume of a sphere * assume density of 1.7g/cm³ (though it could be a loose rubble pile) yields a mass of 5.1e15 kg and an escape velocity of 8.7 m/s (31 km/h)
  5. ^ Denk, T., Mottola, S. (2013): Irregular Saturnian Moon Lightcurves from Cassini-ISS Observations: Update. Abstract 406.08, DPS conference 2013, Denver (Colorado)
  6. ^ Nicholson, P. D. 2001
  7. ^ Daniel W. E. Green (2003-08-08). "IAUC 8177: Sats OF (22); Sats OF JUPITER, SATURN, URANUS". IAU. Retrieved 2011-01-08. 

External links[edit]