|Discovered by||P. J. Melotte|
|Discovery date||January 27, 1908|
|Mean orbit radius||24,094,770 km1|
|Orbital period||764.082032 d (2.092 a)1|
|Average orbital speed||2.242 km/s|
|Inclination||145.24° (to the ecliptic)
143.04° (to Jupiter's equator)1
|Mean radius||30 km2
|Surface area||~11,300 km²|
|Mean density||2.6 g/cm³ (assumed)2|
|Equatorial surface gravity||~0.022 m/s2 (0.002 g)|
|Escape velocity||~0.036 km/s|
Pasiphae (// pə-SIF-ə-ee;4 Greek: Πασιφάη; formerly Pasiphaë)5 is a retrograde irregular satellite of Jupiter. It was discovered in 1908 by Philibert Jacques Melotte67 and later named after the mythological Pasiphaë, wife of Minos and mother of the Minotaur from Greek legend.
It was first spotted on a plate taken at the Royal Greenwich Observatory on the night of February 28, 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 10.8
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°.11 The orbital elements are as of January 2000.1 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).12
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.1314
- 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.
- "Planetary Satellite Physical Parameters". JPL (Solar System Dynamics). 2008-10-24. Retrieved 2008-12-12.
- Williams, Dr. David R. (2007-11-23). "Jovian Satellite Fact Sheet". NASA (National Space Science Data Center). Retrieved 2008-12-12.
- 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.
- Perrine, C. D.; Perrine, C. D. (June 1908). "Recent Observations of the Moving Object Near Jupiter, Discovered at Greenwich by Mr. J. Melotte". Harvard College Observatory Bulletin 20: 184–185. Bibcode:1908PASP...20..184M. doi:10.1086/121815.
- 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.
- IAUC 2846: Satellites of Jupiter 1974 October 7 (naming the moon)
- Payne-Gaposchkin, Cecilia; Katherine Haramundanis (1970). Introduction to Astronomy. Englewood Cliffs, N.J.: Prentice-Hall. ISBN 0-134-78107-4.
- Sheppard, S. S.; Jewitt, D. C.; and Porco, C. C.; Jupiter's Outer Satellites and Trojans, 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
- Nesvorný, D.; Beaugé, C.; and 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.
- Brown, M. E. (2000). "Near-Infrared Spectroscopy of Centaurs and Irregular Satellites". The Astronomical Journal (The American Astronomical Society) 119 (2): 977. Bibcode:2000AJ....119..977B. doi:10.1086/301202.
- Sheppard, S. S.; and Jewitt, D. C.; An Abundant Population of Small Irregular Satellites Around Jupiter, Nature, Vol. 423 (May 2003), pp. 261-263
- Grav, T.; Holman, M. J.; Gladman, B. J.; and Aksnes, K.; Photometric Survey of the Irregular Satellites, Icarus, Vol. 166 (2003), pp. 33-45
- Pasiphae Profile by NASA's Solar System Exploration
- David Jewitt pages
- Scott Sheppard pages
- MPC: Natural Satellites Ephemeris Service