Why does Saturn have Rings?
Saturn is known to be the sixth planet from the sun and the second-largest planet in the solar system. This planet is located at a farther degree from Earth and it is detectable to the naked human eye, but the most magnificent feature of Saturn is it’s rings. The rings of this planet are perceived better through a telescope. Although the other gas giants in the solar system such as Jupiter, Uranus and Neptune. They also own rings, however, rings of Saturn are specifically eminent, earning it the nickname of the “Ringed Planet”.
Saturn is a gas giant which is mainly composed of Hydrogen and Helium. It is insufficient of a definite surface, though it may have a solid core. Saturn’s volume is greater than 760 Earths, and it is considered to be the second most colossal planet in the solar system, and has about 95 times of the Earth’s mass. The Ringed Planet is the least dense of all the planets, and is the only one less heavily than water (about 30 percent less). If there were any bathtub massive enough to hold it, Saturn would float. Although the core of the Saturn is considerably denser than water, but the average specific density of the planet is 0.69 g/cm3 due to the atmosphere.
On the atmosphere of Saturn, one can see yellow and gold bands which results due to the movement of superfast winds in the upper atmosphere, which can raise up to 1,100 mph (1,800 km/h) around its equator, along with the heat rising from the planet’s interior portion. The rotation of Saturn takes place about once every 10.5 hours. The reason for the Saturn to bulge at its equator and flatten at its poles is its high-speed spin. The planet is around 75,000 miles (120,000 kilometres) across at its equator, and 68,000 miles (109,000 km) pole to pole.
The rotation of Saturn changes its shape to an oblate spheroid. It is flattened at the poles and bulges at its equator. Its equatorial and polar radii differ by almost 10%: 60,268 km versus 54,364 km. Jupiter, Uranus, and Neptune, the other giant planets in the Solar System, are also oblate but to a lesser extent. The combination of the bulge and rotation rate means that the effective surface gravity along the equator, 8.96 m/s2, is 74% that at the poles and is lower than the surface gravity of Earth. However, the equatorial escape velocity of nearly 36 km/s is much higher than that for Earth.
Internal structure
Other than comprising of hydrogen and helium, most of Saturn’s mass is not in the gaseous state, as the hydrogen becomes a non-absolute liquid, when the density is especially above 0.01 g/cm3, which is raised to a radius consisting of 99.9% of Saturn’s mass. The temperature, pressure, and density inside Saturn all increase uniformly towards the core, which further results in the conversion of hydrogen to be a metal in the deeper layers.
Standard planetary models advocate that the interior of Saturn is identical to that of Jupiter, having a small rocky core surrounded by hydrogen and helium, with trace of different volatiles. This core is all the same in composition to Earth, but is denser. The evaluation of Saturn’s gravitational moment, in amalgamation with physical models of the interior, has enabled the constraints to be placed on the mass of Saturn’s core. In 2004, scientists approximated that the core must be 9 to 22 times the mass of Earth, which corresponds to a diameter of about 25,000 km. This is encircled by a thicker liquid metallic hydrogen layer, followed by a liquid layer of saturated helium molecular hydrogen which slowly converts to a gas with an accelerating altitude. The outermost layer spans 1,000 km and comprises of gas.
The hot interior of Saturn reaches for 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 elaborate heat production for Saturn, due to its less massiveness. An alternative or additional mechanism may be generation of heat through the “raining out” of droplets of helium deep in Saturn’s interior. As the droplets goes down through the lower-density hydrogen, the process releases heat with the help of friction and leaves the outer layers of Saturn, depleted of helium. These subsiding droplets may have got collected into a helium shell encircling the core. Diamond shaped rainfall have also been suggested to happen within Saturn, and same is the case with Jupiter and ice giants, Uranus and Neptune.
Saturn’s Atmosphere
The outermost atmosphere of Saturn comprises of around 96.3% molecular hydrogen and 3.25% helium by volume. The proportion of helium is notably inadequate in contrast to the huge amount of this element in the Sun. The quantity of elements denser than helium is not known accurately. However, the proportions are supposed to match the primordial amount from the formation of the Solar System. The total mass of these heavier elements is estimated to be 19 to 31 times the mass of the Earth, with a prominent fraction located in Saturn’s core portion.
Traces of ammonia, acetylene, ethane, propane, phosphine, and methane have been found in Saturn’s atmosphere. The overlying clouds are consists of crystals of ammonia, while the lower level clouds appear to comprise of either ammonium hydrosulfide (NH
4SH) or water. Ultraviolet radiation from the Sun undergoes methane photolysis in the upper atmosphere, resulting in a series of hydrocarbon chemical reactions causing the products being carried downward by eddies and diffusion. This photochemical cycle is regulated by Saturn’s annual seasonal cycle.
Magnetosphere
Saturn has an ingrained magnetic field that has a plain and symmetric shape with a magnetic dipole. Its strength at the equator is 0.2 gauss (20 µT) which is estimated as one twentieth of that of the field around Jupiter and also somewhat weaker than Earth’s magnetic field. And as a result of that, Saturn’s magnetosphere gets much smaller than that of Jupiter’s. When Voyager 2 entered the magnetosphere, the pressure of solar wind was high and the magnetosphere extended only 19 Saturn radii, or 1.1 million km (712,000 mi) although it got bigger within a few hours, and remained so for about three days. This magnetosphere is coherent at diverting the particles of solar wind from the Sun. The moon Titan takes the rounds within the outer part of Saturn’s magnetosphere and contributes plasma from the ionized particles in Titan’s outer atmosphere.
Saturn’s Rings
The first one to notice Saturn’s rings was Galileo Galilei, in the year 1610, although by looking through his telescope the rings looked like handles or arms. Forty five years later, in the year 1655, a very famous Dutch astronomer Christiaan Huygens, had a more powerful telescope, later put forward that Saturn had a thin, flat ring.
As scientists enhanced and build better instruments, they continued to acknowledge more about the structure and composition of the rings. Saturn has various rings which are further composed of billions of particles of ice and rock, ranging in size from a grain of sugar to the size of a house. The particles are believed to be debris left over by comets, asteroids or shattered moons. A 2016 study also suggested the rings may be the carcasses of dwarf planets.
The largest ring has a length of about 7,000 times the diameter of the planet. The main rings are typically only about 30 feet thick, but the Cassini-Huygens spacecraft disclosed vertical formations in some of the rings, with particles piling up in bumps and ridges more than 2 miles high. The rings are named alphabetically in the order they were discovered. The main rings, working out from the planet, are known as C, B and A. The innermost is the extremely faint D ring, while the outermost to date, revealed in 2009, is so big that it could fit a billion Earths within it.
Mysterious spokes have been seen in Saturn’s rings, which appear to form and disperse within only a few hours. Scientists have conjectured that these spokes might be composed of electrically charged sheets of dust-size particles created by small meteors impacting the rings, or by electron beams from the planet’s lightning.
Saturn’s F Ring also has a curious braided appearance. The ring is composed of several narrower rings, and bends, kinks and bright clumps in them can give the illusion that these strands are braided. Impacts from asteroids and comets have also altered the appearance of the rings.
Conclusion
Thus, the most colossal planet in the solar system after Jupiter, the pull of Saturn’s gravity has helped shape the fate of our solar system. It may have helped violently toss Neptune and Uranus outward. Along with Jupiter, it might also have suspended a barrage of debris toward the inner planets early in the system’s history.
Scientists are still learning about how gas giants form, and run models on early solar system formation to understand the role that Jupiter, Saturn and other planets play in our solar system.
