SATURN | Space Time

Saturn

Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine times that of Earth. It only has one-eighth the average density of Earth; however, with its larger volume, Saturn is over 95 times more massive. Saturn is named after the Roman god of wealth and agriculture; its astronomical symbol (♄) represents the god's sickle.

Saturn's interior is most likely composed of a core of iron-nickel and rock (silicon and oxygen compounds). Its 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. Saturn has a pale yellow hue due to ammonia crystals in its upper atmosphere. Electrical current within the metallic hydrogen layer is thought to give rise to Saturn's planetary magnetic field, which is weaker than the Earth's but has a magnetic moment 580 times that of Earth due to Saturn's larger size. Saturn's magnetic field strength is around one-twentieth of Jupiter's. The outer atmosphere is generally bland and lacking in contrast, although long-lived features can appear. Wind speeds on Saturn can reach 1,800 km/h (1,100 mph; 500 m/s), higher than on Jupiter, but not as high as those on Neptune. In January 2019, astronomers reported that a day on the planet Saturn has been determined to be 10h 33m 38s + 1m 52s− 1m 19s , based on studies of the planet's C Ring.

The planet's most famous feature is its prominent ring system, which is composed mostly of ice particles, with a smaller amount of rocky debris and dust. At least 82 moons are known to orbit Saturn, of which 53 are officially named; this does not include the hundreds of moonlets in its rings. 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.

INTERNAL STRUCTURE

Despite consisting mostly of hydrogen and helium, most of Saturn's mass is not in the gas phase, because hydrogen becomes a non-ideal liquid when the density is above 0.01 g/cm3, which is reached at a radius containing 99.9% of Saturn's mass. The temperature, pressure, and density inside Saturn all rise steadily toward the core, which causes hydrogen to be a metal in the deeper layers.

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. This core is similar in composition to Earth but is denser. The examination of Saturn's gravitational moment, in combination with physical models of the interior, has allowed constraints to be placed on the mass of Saturn's core. In 2004, scientists estimated that the core must be 9–22 times the mass of Earth, which corresponds to a diameter of about 25,000 km. This is surrounded by a thicker liquid metallic hydrogen layer, followed by a liquid layer of helium-saturated molecular hydrogen that gradually transitions to a gas with increasing altitude. The outermost layer spans 1,000 km and consists of gas.

Saturn has a hot interior, reaching 11,700 °C at its core, and it radiates 2.5 times more energy into space than it receives from the Sun. 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. An alternative or additional mechanism may be the generation of heat through the "raining out" of droplets of helium deep in Saturn's interior. As the droplets descend through the lower-density hydrogen, the process releases heat by friction and leaves Saturn's outer layers depleted of helium. These descending droplets may have accumulated into a helium shell surrounding the core. Rainfalls of diamonds have been suggested to occur within Saturn, as well as in Jupiter and ice giants Uranus and Neptune.

PLANETARY RINGS

Saturn is probably best known for the system of planetary rings that makes it visually unique.] The rings extend from 6,630 to 120,700 kilometres (4,120 to 75,000 mi) outward from Saturn's equator and average approximately 20 meters (66 ft) in thickness. They are composed predominantly of water ice with trace amounts of tholin impurities, and a peppered coating of approximately 7% amorphous carbon.] The particles that make up the rings range in size from specks of dust up to 10 m.] While the other gas giants also have ring systems, Saturn's is the largest and most visible.

There are two main hypotheses regarding the origin of the rings. One hypothesis is that the rings are remnants of a destroyed moon of Saturn. The second hypothesis is that the rings are leftover from the original nebular material from which Saturn was formed. Some ice in the E ring comes from the moon Enceladus's geysers. The water abundance of the rings varies radically, with the outermost ring A being the purest in ice water. This abundance variance may be explained by meteor bombardment.

Beyond the main rings at a distance of 12 million km from the planet is the sparse Phoebe ring, which is tilted at an angle of 27° to the other rings and, like Phoebe, orbits in a retrograde fashion.

Some of the moons of Saturn, including Pandora and Prometheus, act as shepherd moons to confine the rings and prevent them from spreading out. Pan and Atlas cause weak, linear density waves in Saturn's rings that have yielded more reliable calculations of their masses.

SATURNINE FACTS

Saturn is the sixth planet from the Sun and last of the planets known to ancient civilizations. It was known to the Babylonians and Far Eastern observer.
Saturn is one of five planets able to be seen with the naked eye. It is also the fifth brightest object in the solar system.
In Roman mythology, Saturn was the father of Jupiter, king of the gods. This relationship makes sense given that the planets Saturn and Jupiter are similar in so many respects, including size and composition. The Greek counterpart is known as Cronus.
The most common nickname for Saturn is “The Ringed Planet”, a nickname arising from the large, beautiful and extensive ring system that encircles the planet. These rings are mostly made from chunks of ice and carbonaceous dust. They stretch out more than 12,700 km from the planet but are only a mere 20 meters thick.
Saturn gives off more energy than it receives from the Sun. This unusual quality is believed to be generated from the gravitational compression of the planet combined with the friction from a large amount of helium found within its atmosphere.
It takes Saturn 29.4 Earth years to orbit the Sun. This slow movement against a backdrop of stars led to the planet being nicknamed “Lubadsagush” – or “oldest of the old” – by the ancient Assyrians.
Saturn has the fastest winds of any other planet in our solar system. These winds have been measured at approximately 1,800 km per hour (1,100 miles per hour).
Saturn is the least dense planet in the solar system. It is made mostly of hydrogen and has a density which is less than water – which technically means that Saturn would float. The layers of hydrogen get denser further into the planet, eventually becoming metallic and leading to a hot interior core.
Saturn has 150 moons and smaller moonlets. All of these moons are frozen – the largest of which is Titan and Rhea. The moon Enceladus also appears to have an ocean hidden below its frozen surface.
Saturn’s moon Titan is the second-largest moon in the Solar System, behind Jupiter’s moon Ganymede. It has a complex and dense atmosphere made mostly of nitrogen and is composed of water ice and rock. The frozen surface of Titan has liquid methane lakes and a landscape which is covered with frozen nitrogen. Titan may be a harbour for life – but that life would not be similar to life on Earth.
Saturn is the flattest of the eight planets. With a polar diameter that is 90% of its equatorial diameter, Saturn is the flattest of all the planets. This is because of the planet’s low density and fast rotation speed – it takes Saturn 10 hours and 34 minutes to turn on its axis.
Saturn has oval-shaped storms which are similar to those of Jupiter. Scientists believe that the hexagonal-shaped pattern of clouds around Saturn’s north pole may be a wave pattern in the upper clouds. There is also a vortex over the south pole which resembles hurricane storms on Earth.
Saturn appears a pale yellow colour because its upper atmosphere contains ammonia crystals. Below this top layer of ammonia ice are clouds that are largely water ice. Even further below that are layers of sulfur ice and cold hydrogen mixtures.
Saturn has been visited by four spacecraft. These are Pioneer 11, Voyager 1 and 2 and the Cassini-Huygen mission. Cassini entered into orbit around Saturn on July 1, 2004, and continues to send back information about the planet, its ring and many moons.
The magnetic field on Saturn is slighter weaker than Earth’s magnetic field. Saturn’s magnetic field strength is around one-twentieth the strength of Jupiter’s
Saturn is known as a gas giant, but scientists believe it has a solid rocky core surrounded by hydrogen and helium
Saturn and Jupiter combined account for 92% of the entire planetary mass in the solar system.
The interior of Saturn is very hot, reaching temperatures of up to 11,700°C (21,000 °F).
Saturn is 1,424,600,000 km from the Sun. This is around 0.9 billion miles.