Pasiphae (moon)


Pasiphae photographed by the Haute-Provence Observatory in August 1998
Discovery [1]
Discovered byPhilibert J. Melotte
Discovery siteRoyal Observatory, Greenwich
Discovery date27 January 1908
Jupiter VIII
Named after
Πασιφάη Pāsiphaē
1908 CJ
AdjectivesPasiphaëan /ˌpæsɪfˈən/[4]
Orbital characteristics[5]
Epoch 23 March 2018 (JD 2458200.5)
Observation arc110.34 yr (40,303 days)
0.1551422 AU (23,208,940 km)
–722.34 d
0° 29m 54.18s / day
Inclination153.40903° (to ecliptic)
Satellite ofJupiter
GroupPasiphae group
Physical characteristics
Mean diameter
57.8±0.8 km[6]

Pasiphae /pəˈsɪf./, formerly spelled Pasiphaë,[8] is a retrograde irregular satellite of Jupiter. It was discovered in 1908 by Philibert Jacques Melotte[1][9] and later named after the mythological Pasiphaë, wife of Minos and mother of the Minotaur from Greek legend.

The moon was first spotted on a plate taken at the Royal Greenwich Observatory on the night of 28 February 1908. Inspection of previous plates found it as far back as January 27. It received the provisional designation 1908 CJ, as it was not clear whether it was an asteroid or a moon of Jupiter. The recognition of the latter case came by April 10.[10]

Pasiphae did not receive its present name until 1975;[11] before then, it was simply known as Jupiter VIII. It was sometimes called "Poseidon"[12] between 1955 and 1975.


Retrograde irregular satellites of Jupiter.

Pasiphae orbits Jupiter on a high eccentricity and high inclination retrograde orbit. It gives its name to the Pasiphae group, irregular retrograde moons orbiting Jupiter at distances ranging between 22.8 and 24.1 million km, and with inclinations ranging between 144.5° and 158.3°.[13] The orbital elements are as of January 2000.[14] They are continuously changing due to solar and planetary perturbations. The diagram illustrates its orbit in relation to other retrograde irregular satellites of Jupiter. The eccentricity of selected orbits is represented by the yellow segments (extending from the pericentre to the apocentre). The outermost regular satellite Callisto is located for reference.

Pasiphae is also known to be in a secular resonance with Jupiter (tying the longitude of its perijove with the longitude of perihelion of Jupiter).[15]

Physical characteristics

Pasiphae observed by the Wide-field Infrared Survey Explorer (WISE) spacecraft in 2014

With diameter estimated at 60 km Pasiphae is the largest retrograde and third largest irregular satellite after Himalia and Elara.

Spectroscopical measurements in infrared indicate that Pasiphae is a spectrally featureless object, consistent with the suspected asteroidal origin of the object. Pasiphae is believed to be a fragment from a captured asteroid along with other Pasiphae group satellites.[16][17]

In the visual spectrum the satellite appears grey (colour indices B-V=0.74, R-V=0.38) similar to C-type asteroids.[18]

See also


  1. ^ a b Melotte, P. J. (1908). "Note on the Newly Discovered Eighth Satellite of Jupiter, Photographed at the Royal Observatory, Greenwich". Monthly Notices of the Royal Astronomical Society. 68 (6): 456–457. Bibcode:1908MNRAS..68..456.. doi:10.1093/mnras/68.6.456.
  2. ^ Noah Webster (1884) A Practical Dictionary of the English Language
  3. ^ "Pasiphae". Unabridged. Random House.
  4. ^ Laurent Milesi (2003) James Joyce and the difference of language, p. 149
  5. ^ a b "M.P.C. 111777" (PDF). Minor Planet Circular. Minor Planet Center. 25 September 2018.
  6. ^ a b Grav, T.; Bauer, J. M.; Mainzer, A. K.; Masiero, J. R.; Nugent, C. R.; Cutri, R. M.; et al. (August 2015). "NEOWISE: Observations of the Irregular Satellites of Jupiter and Saturn". The Astrophysical Journal. 809 (1): 9. arXiv:1505.07820. Bibcode:2015ApJ...809....3G. doi:10.1088/0004-637X/809/1/3. S2CID 5834661. 3.
  7. ^ Sheppard, Scott. "Scott S. Sheppard - Jupiter Moons". Department of Terrestrial Magnetism. Carnegie Institution for Science. Retrieved 26 November 2020.
  8. ^
  9. ^ Perrine, C. D.; Perrine, C. D. (June 1908). "Recent Observations of the Moving Object Near Jupiter, Discovered at Greenwich by Mr. J. Melotte". Publications of the Astronomical Society of the Pacific. 20 (120): 184–185. Bibcode:1908PASP...20..184M. doi:10.1086/121815.
  10. ^ Cowell, P. H. (1908). "Note on the Discovery of a Moving Object Near Jupiter". Monthly Notices of the Royal Astronomical Society. 68: 373. Bibcode:1908MNRAS..68..373.. doi:10.1093/mnras/68.5.373.
  11. ^ IAUC 2846: Satellites of Jupiter 7 October 1974 (naming the moon)
  12. ^ Payne-Gaposchkin, Cecilia; Katherine Haramundanis (1970). Introduction to Astronomy. Englewood Cliffs, N.J.: Prentice-Hall. ISBN 0-134-78107-4.
  13. ^ Sheppard, S. S.; Jewitt, D. C.; and Porco, C. C.; Jupiter's Outer Satellites and Trojans Archived 2007-06-14 at the Wayback Machine, in Jupiter: The Planet, Satellites and Magnetosphere, edited by Fran Bagenal, Timothy E. Dowling, and William B. McKinnon, Cambridge Planetary Science, Vol. 1, Cambridge, UK: Cambridge University Press, ISBN 0-521-81808-7, 2004, pp. 263-280
  14. ^ Jacobson, R. A. (2000). "The Orbits of the Outer Jovian Satellites". Astronomical Journal. 120 (5): 2679–2686. Bibcode:2000AJ....120.2679J. doi:10.1086/316817.
  15. ^ Nesvorný, D.; Beaugé, C.; Dones, L. (2004). "Collisional Origin of Families of Irregular Satellites". The Astronomical Journal. 127 (3): 1768–1783. Bibcode:2004AJ....127.1768N. doi:10.1086/382099.
  16. ^ Brown, M. E. (2000). "Near-Infrared Spectroscopy of Centaurs and Irregular Satellites". The Astronomical Journal. The American Astronomical Society. 119 (2): 977–983. Bibcode:2000AJ....119..977B. CiteSeerX doi:10.1086/301202.
  17. ^ Sheppard, S. S.; and Jewitt, D. C.; An Abundant Population of Small Irregular Satellites Around Jupiter Archived 5 August 2003 at the Wayback Machine, Nature, Vol. 423 (May 2003), pp. 261-263
  18. ^ Grav, T.; Holman, M. J.; Gladman, B. J.; and Aksnes, K.; Photometric Survey of the Irregular Satellites, Icarus, Vol. 166 (2003), pp. 33-45

External links

  • Pasiphae Profile by NASA's Solar System Exploration
  • David Jewitt pages
  • Scott Sheppard pages
  • MPC: Natural Satellites Ephemeris Service