Calypso (Saturn XIV)
A satellite of Saturn discovered in 1980 on the images taken by Voyager 1. It shares the same orbit as Telesto and Tethys at a distance of 294,660 km and turns around the planet with a period of 1.888 days. It is 34 x 22 x 22 km in size.
In Greek mythology, Calypso was a sea nymph and the daughter of the Titan Atlas.
Dione (Saturn IV)
The fourth largest moon of Saturn and the second densest after Titan. Its diameter is 1,120 km and its orbit 377,400 km from Saturn. It is composed primarily of water ice but must have a considerable fraction of denser material like silicate rock.
Discovered in 1684 by Jean-Dominique Cassini, Italian born French astronomer (1625-1712). In Gk. mythology Dione was the mother of Aphrodite (Venus) by Zeus (Jupiter).
Enceladus (Saturn II)
The eighth of Saturn's known satellites, about 500 km in diameter, it orbits Saturn at a mean distance of 238,000 km with a period of 1.37 days. Enceladus has the highest albedo (> 0.9) of any body in the solar system. Its surface is dominated by clean ice. Discovered by Herschel in 1789.
In Gk. mythology Enceladus was a Titan who battled Athene in their war against the gods. When he fled the battlefield, Athene crushed him beneath the Sicilian Mount Etna.
Enkelâdos, from the original Gk. pronunciation of the name.
Hyperion (Saturn VII)
The sixteenth of → Saturn's known → natural satellites. It is shaped like a potato with dimensions of 410 x 260 x 220 km and has a bizarre porous, sponge-like appearance. Many of the sponge holes or craters have bright walls, which suggests an abundance of → water → ice. The crater floors are mostly the areas of the lowest → albedo and greatest red coloration. This may be because the average temperature of roughly -180 °C might be close enough to a temperature that would cause → volatiles to → sublimate, leaving the darker materials accumulated on the crater floors. Hyperion is one of the largest bodies in the → Solar System known to be so irregular. Its density is so low that it might house a vast system of caverns inside. Hyperion rotates chaotically and revolves around Saturn at a mean distance of 1,481,100 km. It was discovered by two astronomers independently in 1848, the American William C. Bond (1789-1859) and the British William Lassell (1799-1880).
Hyperion, in Gk. mythology was the Titan god of light, one of the sons of Ouranos (Heaven) and Gaia (Earth), and the father of the lights of heaven, Eos the Dawn, Helios the Sun, and Selene the Moon.
The sixth planet from the Sun and the second largest with an equatorial diameter of 120,536 km orbiting at 1,429,400,000 km (9.54 AU) from Sun. Like Jupiter, Saturn is about 75% hydrogen and 25% helium with traces of water, methane, and ammonia, similar to the composition of the primordial Solar Nebula from which the solar system was formed. Saturn's interior is similar to Jupiter's consisting of a rocky core, a liquid metallic hydrogen layer and a molecular hydrogen layer. Saturn's interior is hot (12,000 K at the core). The planet radiates more energy into space than it receives from the Sun. Saturn has 34 known satellites. → Saturn's ring.
O.E. Sætern "Italic god," also "most remote planet" (then known), from L. Saturnus, Italic god of agriculture, possibly from Etruscan.
Keyvân Mid.Pers. Kêwân, borrowed from Aramean kâwân, from Assyrian kaiamânu.
Fr.: nébuleuse Saturne
A planetary nebula in the Aquarius constellation discovered by William Herschel in 1782. It has a size of about 0.3 x 0.2 light-years and lies about 1400 light-years away. Also known as NGC 7009.
halqehâ-ye Keyvân (#)
Fr.: anneaux de Saturne
A system of rings around Saturn made up of countless small particles, ranging in size from micrometers to meters, that orbit the planet. The ring particles are made almost entirely of → water ice, with some contamination from → dust and other chemicals. The ring system is divided into six major components: D, C, B, A, F, and G rings, listed from inside to outside. But in reality, these major divisions are subdivided into thousands of individual → ringlets. The large gap between the A and B rings is called the Cassini division. Saturn's rings are extraordinarily thin: though they are 250,000 km or more in diameter, they are less than one kilometer thick. → A ring, → B ring, → C ring, → D ring, → F ring, → G ring.