Saturn is the sixth planet from the Sun and second largest planet in the Solar System in terms of diameter and mass. If compared, it is easy to see why Saturn and Jupiter have been designated as relatives when naming them. From atmospheric composition to rotation, these two planets are extremely similar. Because of these factors, Saturn was named after the father of the god Jupiter in Roman mythology.
Other than Earth (the Small Blue Dot), Saturn is easily the most recognizable planet in the Solar System. The other gas giants possess planetary ring systems, but none other can match the size or beauty of the one found encircling Saturn.
The Comparative Size of the Planets
Facts About Saturn
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 large amount of helium found within its atmosphere.
Saturn is the least dense planet in the solar system. The overall mass of Saturn is 100 times that of the Earth but it’s density is 1/8ththat of Earth. Although Saturn may have a dense, solid core, the large gaseous outer layer of the planet makes its average density a mere 687 kg/m3. It is made mostly of hydrogen and has a density which is less than water – which technically means that Saturn would float on water.
Saturn has 150 moons and smaller moonlets. All of these moons are frozen – the largest of which are Titan and Rhea. The moon Enceladus also appears to have an ocean hidden below its frozen surface.
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 appears a pale yellow color 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.
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 and Jupiter combined account for 92% of the entire planetary mass in the solar system.
Saturn is 1,424,600,000 km from the Sun. This is around 0.9 billion miles.
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.
Saturn’s atmosphere is composed of roughly 96% hydrogen and 4% helium, with trace amounts of ammonia, acetylene, ethane, phosphine and methane. It has a thickness of approximately 60 km. In the highest layer of the atmosphere, wind speeds reach 1,800 km/h, easily some of the fastest in the entire Solar System. Although not as visible as those seen on Jupiter, Saturn does possess a horizontally banded cloud pattern. Furthermore, these bands are considerably wider near Saturn’s equator than those found at Jupiter’s equator. Another fascinating phenomenon that can be found in Saturn’s atmosphere is the appearance of great white spots. These are storms on Saturn, which are analogous to the Great Red Spotfound on Jupiter, though they are much shorter lived. The Hubble Space Telescope observed such a storm in 1990, though it was not present when the Voyager spacecraft had flown by in 1981. Based on historical observations, it appears that these storms are periodic in nature, occurring approximately once per Saturnian orbit.
The interior of Saturn is believed to be extremely similar to Jupiter’s in the composition of its three layers. The innermost layer is a rocky core between 10-20 times as massive as the Earth. The core is encased in a layer of liquid metallic hydrogen. The outermost layer is composed of molecular hydrogen (H2). Whereas Jupiter has a metallic hydrogen layer of 46,000 km and molecular hydrogen layer of is 12,200 km, those same layers on Saturn have a thickness of 14,500 km and 18,500 km, respectively. Saturn, like Jupiter, emits approximately 2.5 times more radiation than it receives from the Sun. This is due to the fact that Saturn essentially creates energy through gravitational compression of its enormous mass. However, unlike Jupiter, the total amount of energy emitted cannot be accounted for through this process alone. Instead, scientists have suggested that the planet generates additional heat through the friction of helium rain.
Orbit and Rotation
The average orbital distance of Saturn is 1.43 x 109 km. This means that Saturn is, on average, about 9.5 times the distance from the Earth to the Sun. Given Saturn’s distance from the Sun, it has a year lasting 10,756 Earth days; that is, about 29.5 Earth years. This slow movement against the backdrop of stars led the ancient Assyrians to name the planet “Lubadsagush” – or “oldest of the old”. Saturn’s axial tilt of 26.73 is very similar to the Earth’s. Thus Saturn also experiences seasons like the Earth. However, due to Saturn’s distance from the Sun, it receives significantly less solar radiation year-round, and so Saturn’s season differences are less marked than those on Earth. Saturn is second only to Jupiter for the fastest rotation in the Solar System with a rotational speed of 10 hours 45 minutes. This extreme rotation causes the planet’s shape to take on the shape of an oblate spheroid; i.e. a sphere that bulges near its equator. A second feature of Saturn’s rotation is the different rotational speeds found between the different visible latitudes. This phenomenon is due to Saturn being primarily gaseous rather than solid.
The ring system of Saturn is the most prominent found in the Solar System. They are composed primarily of billions of tiny ice particles, with traces of dust and other debris. This composition explains why the rings are visible to Earth-based telescopes—ice is very reflective of sunlight. There are seven broad classifications among the rings: A, B, C, D, E, F, G, each receiving its name in the order it was discovered. Between each ring there are gaps. The main rings begin roughly 7,000 km above Saturn’s equator and extend out another 73,000 km. Interestingly, though this radius is substantial, the actual thickness of the rings is no more than about one kilometre. The most common theory used to explain the formation of the rings is that a medium-sized moon orbiting Saturn broke apart due to tidal forces when its orbit became too close to Saturn.
Now let’s sum up the conditions on Jupiter that preclude the existence of life.
It’s hard to imagine a planet less hospitable for life than Saturn. The planet is comprised almost entirely hydrogen and helium, with only trace amounts of water ice in its lower cloud deck. Temperatures at the top of the clouds can dip down to -150 C. Temperatures do get warmer as you descend into Saturn’s atmosphere, but the pressures increase too. When temperatures are warm enough to have liquid water, the pressure of the atmosphere is the same as several kilometres beneath the ocean on Earth. Aside from the fact there are only trace amounts of oxygen available to breath your lungs would collapse under the pressure.
As a giant gas planet, Saturn doesn't have solid ground; scientists set the surface of the planet at the point where pressure is equal to that of sea level on Earth. On Saturnthere arethree layers of clouds. The upper layers of ammonia ice have temperatures ranging from minus 280 F (minus 173 C) to minus 170 F (113 C).
With an average temperature of minus 288 degrees Fahrenheit (minus 178 degrees Celsius), Saturn is too cold to support life as we know it on Earth. There are small differences in temperature as one travels from the equator to the poles, much of Saturn's temperature variation is horizontal. This is because most of the planet's heat comes from its interior, rather than from the sun.
Being mostly hydrogen with some helium other gases such as sulphur, methane, ammonia, nitrogen and oxygen lie within the planet's atmosphere in small amounts creating colourful bands. There would be beautiful sunsets on Saturn once every 29 years but you would find it impossible to breath due to the lack of oxygen. As a giant gas planet, Saturn doesn't have solid ground; scientists set the surface of the planet at the point where pressure is equal to that of sea level on Earth. Therefore it is impossible to buy real estate.
Saturn contains a rocky core, 10 to 20 times the mass of Earth, which is surrounded by liquid metallic hydrogen. This massive core was likely the first part of the planet created, and it trapped gas as the plnet formed. Moving out from the core, the liquid hydrogen becomes less metallic, gradually shifting into a gas the further one travels from the centre of the planet.
The interior may reach temperatures of up to 21,000 F (11,700 C). Most of the planet's heat comes from its core. Saturn radiates more than twice as much heat into space as it receives from the sun. Much of the heat is caused by the gravitational compression of the planet, but scientists theorize that some of it may come from friction created by helium sinking into the planet's interior.To live on Saturn would be like sitting on a volcano ready to blow.
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). But on Saturn such storms don't appear to constant.
The answer to our question is then – most decidedly not!
Next week we will look at Uranus, but frankly I don't think anyone would want to live on a planet named Uranus.