Saturn

Atmosphere of SaturnOrbit of SaturnPhainonplanet SaturnSaturn's atmosphereDr. SaturnExploration of SaturnHistory of Saturnhome planetplanet
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter.wikipedia
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Solar System

outer Solar Systeminner Solar Systemouter planets
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter.
The two largest, Jupiter and Saturn, are gas giants, being composed mainly of hydrogen and helium; the two outermost planets, Uranus and Neptune, are ice giants, being composed mostly of substances with relatively high melting points compared with hydrogen and helium, called volatiles, such as water, ammonia and methane.

Planet

planetsFormer classification of planetsplanemo
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter.
In order of increasing distance from the Sun, they are the four terrestrials, Mercury, Venus, Earth, and Mars, then the four giant planets, Jupiter, Saturn, Uranus, and Neptune.

Ammonia

NH 3 anhydrous ammonialiquid ammonia
Saturn has a pale yellow hue due to ammonia crystals in its upper atmosphere.
Ammonia is also found throughout the Solar System on Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto, among other places: on smaller, icy bodies such as Pluto, ammonia can act as a geologically important antifreeze, as a mixture of water and ammonia can have a melting point as low as 173 K if the ammonia concentration is high enough and thus allow such bodies to retain internal oceans and active geology at a far lower temperature than would be possible with water alone.

Moons of Saturn

moon of Saturnmoonmoons
At least 82 moons are known to orbit Saturn, of which 53 are officially named.
Saturn has 82 moons with confirmed orbits that are not embedded in its rings – of which only 13 have diameters greater than 50 kilometers – as well as dense rings that contain millions of embedded moonlets and innumerable smaller ring particles.

Saturn (mythology)

SaturnSaturnusSaturnian
Saturn is named after the Roman god of wealth and agriculture; its astronomical symbol represents the god's sickle.
The planet Saturn and the day of the week Saturday are both named after him.

Jupiter

JovianGioveplanet Jupiter
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. Standard planetary models suggest that the interior of Saturn is similar to that of Jupiter, having a small rocky core surrounded by hydrogen and helium with trace amounts of various volatiles.
Based on spectroscopy, Saturn is thought to be similar in composition to Jupiter, but the other giant planets Uranus and Neptune have relatively less hydrogen and helium and relatively more ices and are thus now termed ice giants.

Titan (moon)

TitanSaturn's moon Titanatmosphere
Titan, Saturn's largest moon, and the second-largest in the Solar System, is larger than the planet Mercury, although less massive, and is the only moon in the Solar System to have a substantial atmosphere.
Titan is the sixth gravitationally rounded moon from Saturn.

Metallic hydrogen

liquid metallic formLiquid metallic hydrogenmetallic state
This core is surrounded by a deep layer of metallic hydrogen, an intermediate layer of liquid hydrogen and liquid helium, and finally a gaseous outer layer.
At high pressure and temperatures, metallic hydrogen can exist as a liquid rather than a solid, and researchers think it might be present in large quantities in the hot and gravitationally compressed interiors of Jupiter, Saturn, and in some exoplanets.

Gas giant

gas giantsgiant planetJovian
It is a gas giant with an average radius about nine times that of Earth.
Jupiter and Saturn are the gas giants of the Solar System.

Uranus

Uranian34 TauriMagnetosphere of Uranus
Jupiter, Uranus, and Neptune, the other giant planets in the Solar System, are also oblate but to a lesser extent. Rainfalls of diamonds have been suggested to occur within Saturn, as well as in Jupiter and ice giants Uranus and Neptune.
Uranus is similar in composition to Neptune, and both have bulk chemical compositions which differ from that of the larger gas giants Jupiter and Saturn.

Cosmic dust

interstellar dustdustspace dust
The planet's most famous feature is its prominent ring system that is composed mostly of ice particles, with a smaller amount of rocky debris and dust.
In the Solar System, dust plays a major role in the zodiacal light, Saturn's B Ring spokes, the outer diffuse planetary rings at Jupiter, Saturn, Uranus and Neptune, and comets.

Astronomical symbols

astronomical symbolastronomicalastronomy
Saturn is named after the Roman god of wealth and agriculture; its astronomical symbol represents the god's sickle.

Cassini–Huygens

CassiniCassini-HuygensCassini spacecraft
In images from the Cassini spacecraft during 2007, Saturn's northern hemisphere displayed a bright blue hue, similar to Uranus.
The Cassini–Huygens space-research mission, commonly called Cassini, involved a collaboration between NASA, the European Space Agency (ESA), and the Italian Space Agency (ASI) to send a probe to study the planet Saturn and its system, including its rings and natural satellites.

Earth mass

mass of Earthmass of the EarthEarth's mass
Jupiter has 318 times Earth's mass, and Saturn is 95 times Earth's mass. Together, Jupiter and Saturn hold 92% of the total planetary mass in the Solar System.

Great White Spot

The 1990 storm was an example of a Great White Spot, a unique but short-lived phenomenon that occurs once every Saturnian year, roughly every 30 Earth years, around the time of the northern hemisphere's summer solstice.
The Great White Spot, also known as Great White Oval, on Saturn, named by analogy to Jupiter's Great Red Spot, are periodic storms that are large enough to be visible from Earth through telescope by their characteristic white appearance.

Neptune

NeptunianAtmosphere of NeptuneNeptune-mass
Wind speeds on Saturn can reach 1800 km/h, higher than on Jupiter, but not as high as those on Neptune. Rainfalls of diamonds have been suggested to occur within Saturn, as well as in Jupiter and ice giants Uranus and Neptune.
Neptune, like Uranus, is an ice giant, a subclass of giant planet, because they are smaller and have higher concentrations of volatiles than Jupiter and Saturn.

Kelvin–Helmholtz mechanism

gravitational contractionKelvin–Helmholtz heatingKelvin–Helmholtz luminosity
Jupiter's thermal energy is generated by the Kelvin–Helmholtz mechanism of slow gravitational compression, but such a process alone may not be sufficient to explain heat production for Saturn, because it is less massive.
This mechanism is evident on Jupiter and Saturn and on brown dwarfs whose central temperatures are not high enough to undergo nuclear fusion.

Voyager program

VoyagerVoyager spacecraftVoyager mission
Voyager data indicate peak easterly winds of 500 m/s.
The probes were launched in 1977 to take advantage of a favorable alignment of Jupiter, Saturn, Uranus, and Neptune.

Flattening

oblatenessellipticityflattened
Saturn's rotation causes it to have the shape of an oblate spheroid; that is, it is flattened at the poles and bulges at its equator.
Other values in the Solar System are Jupiter, f = 1/16; Saturn, f = 1/10, the Moon f = 1/900.

Ice giant

ice giantsice giant planetice giant planets
Rainfalls of diamonds have been suggested to occur within Saturn, as well as in Jupiter and ice giants Uranus and Neptune.
In the 1990s, it was realized that Uranus and Neptune are a distinct class of giant planet, separate from the other giant planets, Jupiter and Saturn.

Atmosphere

atmosphericatmospheresplanetary atmospheres
The outer atmosphere is generally bland and lacking in contrast, although long-lived features can appear.
The low temperatures and higher gravity of the Solar System's giant planets—Jupiter, Saturn, Uranus and Neptune—allow them more readily to retain gases with low molecular masses.

Spheroid

oblate spheroidoblateprolate spheroid
Saturn's rotation causes it to have the shape of an oblate spheroid; that is, it is flattened at the poles and bulges at its equator.
The oblate spheroid is the approximate shape of many planets and celestial bodies, including Saturn, Jupiter and the quickly-spinning star, Altair.

Moonlet

tiny moons
This does not include the hundreds of moonlets in the rings.

Volatiles

volatileicesice
Standard planetary models suggest that the interior of Saturn is similar to that of Jupiter, having a small rocky core surrounded by hydrogen and helium with trace amounts of various volatiles.
Thus, Jupiter and Saturn are gas giants, and Uranus and Neptune are ice giants, even though the vast majority of the "gas" and "ice" in their interiors is a hot, highly dense fluid that gets denser as the center of the planet is approached.

Hydrocarbon

hydrocarbonsliquid hydrocarbonHC
Ultraviolet radiation from the Sun causes methane photolysis in the upper atmosphere, leading to a series of hydrocarbon chemical reactions with the resulting products being carried downward by eddies and diffusion.
Lakes of liquid methane and ethane have been found on Titan, Saturn's largest moon, confirmed by the Cassini-Huygens Mission.