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The Pasiphae group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Pasiphae and are thought to have a common origin. Their semi-major axes (distances from Jupiter) range between 22.8 and 24.1 million km (the same range as the Carme group), their inclinations between 144.5° and 158.3°, and their eccentricities between 0.25 and 0.43. Core members of the group include (from the largest to the smallest):〔 Scott S. Sheppard, David C. Jewitt, Carolyn Porco ''Jupiter's outer satellites and Trojans'', In: ''Jupiter. The planet, satellites and magnetosphere.'' Edited by Fran Bagenal, Timothy E. Dowling, William B. McKinnon. Cambridge planetary science, Vol. 1, Cambridge, UK: Cambridge University Press, ISBN 0-521-81808-7, 2004, p. 263 - 280 (Full text(pdf). )〕 * Pasiphae * Sinope, two-thirds the size of Pasiphae * Callirrhoe * Megaclite * Autonoe * Eurydome * Sponde The International Astronomical Union (IAU) reserves names ending in -e for all retrograde moons, including this group's members. ==Origin== The Pasiphae group is believed to have been formed when Jupiter captured an asteroid which subsequently broke up after a collision. The original asteroid was not disturbed heavily: the original body is calculated to have been 60 km in diameter, about the same size as Pasiphae; Pasiphae retains 99% of the original body's mass. However, if Sinope belongs to the group, the ratio is much smaller, 87%.〔 However, Nesvorny 2003, while concurring on the Ananke and Carme groups, lists only Megaclithe for Pasiphaë's group〕 Unlike the Carme and Ananke groups, the theory of a single impact origin for the Pasiphaë group is not accepted by all studies. This is because the Pasiphae group, while similar in semi-major axis, is more widely dispersed in inclination. Alternatively, Sinope might be not a part of the remnants of the same collision and captured independently instead.〔Grav, Tommy; Holman, Matthew J.; Gladman, Brett J.; Aksnes, Kaare ''Photometric survey of the irregular satellites'', Icarus, 166,(2003), pp. 33-45. (Preprint )〕 The differences of colour between the objects (grey for Pasiphae, light red for Callirrhoe and Megaclite) also suggest that the group could have a more complex origin than a single collision.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pasiphae group」の詳細全文を読む スポンサード リンク
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