Planet Saturn

Saturn is a gigantic frozen ball of gas, surrounded by rings spinning at breakneck speed. A true gem of the solar system and often referred to as “The Lord of the Rings”, it is a magnificent planet that continues to dazzle observers. It is the favorite planet of many amateur astronomers, because it is the only one in the solar system that has rings that are visible so easily. In this article, you will find all about Saturn for: god, temperature, distance to Earth, color, composition, astrology, peculiarity and many more.

Despite its beauty, the climatic conditions reigning on Saturn are maddening: the power of lightning is a million times greater than those observed on Earth. In addition, she is completely frozen. If we were to land on it, we couldn’t, because we would fall, and we would instantly freeze!

Saturn is the sixth planet in the Solar System in order of distance from the Sun, and the second largest in size and mass after Jupiter, which is like it a gas giant planet. Its average radius of 58,232 km is about nine and a half times that of the Earth, and its mass of 568.46 × 1024 kg is 95 times greater. Orbiting on average about 1.4 billion kilometers from the Sun (9.5 astronomical units), its period of revolution is just under 30 years while its period of rotation is estimated at 10 h 33 min.

Read also: The order of the planets closest to the sun

The most famous feature of the planet is its prominent ring system. Composed mainly of particles of ice and dust, they were observed for the first time in 1610 by Galileo and would have formed less than 100 million years ago. In addition, it is the planet with the largest number of natural satellites with 82 confirmed and hundreds of minor satellites in its procession. Its largest moon, Titan, is also the second largest in the Solar System – its diameter being larger than that of the planet Mercury – and is the only known moon to have a substantial atmosphere. Another remarkable moon, Enceladus, emits powerful ice geysers and is said to be a potential habitat for microbial life.

Saturn, majesty of the solar system

The interior of Saturn is very probably composed of a rocky core of silicates and iron surrounded by layers made up by volume of 96% hydrogen which is successively metallic then liquid then gaseous, mixed with helium. Thus, it does not have a solid surface and is the planet with the lowest average density with 0.69 g / cm3 – 70% of that of water. An electric current in the metallic hydrogen layer gives rise to its magnetosphere, the second largest in the Solar System but much smaller than that of Jupiter. Saturn’s atmosphere is generally drab and lacks contrast, although long-lasting features can appear as a hexagon at its north pole. The winds on Saturn can reach a speed of 1,800 km / h, the second fastest in the Solar System after those of Neptune. It was explored by four space probes: Pioneer 11, Voyager 1 and 2 then Cassini-Huygens (named after two astronomers who greatly advanced knowledge of the Saturnian system in the seventeenth century).

Observable with the naked eye in the night sky thanks to its average apparent magnitude of 0.46 – although having a lower brightness than that of other planets – it has been known since prehistoric times and has thus long been the planet farthest from the Sun known. Also, its observation inspired myths and it bears the name of the Roman god of agriculture Saturn (Cronos in Greek mythology), its astronomical symbol ♄ representing the sickle of the god.

Place in the solar system: 6th planet
Size: 116,464 km in diameter (2nd largest planet, 750 times the size of Earth)
Mass: 5.683 × 10 ^ 26 kg
Distance to the sun: 1.429 billion km
Maximum distance from Earth: 1,658 million km
Temperature: -180 ° C
1 day on Saturn: 10.6 hours.
A Saturnian year: 29.5 years
Surface: Hydrogen and helium gas

Atmosphere

Composition and formation

Saturn is mainly composed of helium and hydrogen, and has a very low density: even though its mass is much greater than that of Earth, it would weigh a little less if we could land on it; less dense than water, it would float if it were plunged into an ocean!

4.5 billion years ago, Saturn formed its nucleus from the agglomeration of carbon dust. It is believed that this nucleus is much larger than the Earth. Subsequently, the gravitational force of this super nucleus attracted gaseous particles such as helium and hydrogen. Then these elements collapsed under the effect of gravitational force, creating a thick cloud that began to compress, and spin faster and faster.

The rings of Saturn

If Saturn has achieved the rank of star of the solar system, it is of course thanks to the magnificent rings that surround it. Their size is incredible: 360,000 km in diameter (more than 20 times that of the Earth).

If we launched a rocket, it would take two days for it to go from one side of the rings to the other. However, their thickness is incredibly thin: barely ten meters! When viewed through a telescope, Saturn’s rings look like a flat, solid disc. But in reality, they’re made up of billions of dust and icy asteroids orbiting Saturn.

They can vary in size from a single grain of sand to asteroids the size of a mountain. They are made largely of frozen water. These are heaps of particles that have collided with each other to form smaller particles.

These rings are so numerous that it would be impossible for a spacecraft to pass through them, especially as they rotate at speeds of up to 65,000 km / h. If a particle the size of a grain of sand struck a spaceship, the effect would be the same as a pistol shot at close range!

These rings are the subject of a great mystery to the scientific community. They could have been moons that would have ended up colliding to create this circular mass. Galileo was the first to see the rings of Saturn, in 1610. But at the time, Galileo did not understand what he was seeing. He then describes the rings as objects on either side of Saturn. He would never have known that these objects were rings.

It wasn’t until 45 years later that Christiaan Huygens understood better what it was. He thinks it’s a flat, solid ring. Later, Jean-Dominique Cassini discovers that there are actually several separate rings. Nowadays, the greatest separation of them is called the Cassini Division.

The main rings are seven in number, listed in chronological order of their discovery, and named A to G. It was the Voyager probe that sent stunning images of these rings to Earth for the first time.

Saturn’s rings are highly visible because they are mostly made of ice, a material that reflects sunlight particularly well.

Some scientists believe that these rings are relatively new (a few hundred million years old), and that they will eventually disappear. In comparison, the rings of Neptune and Uranus are much thinner, but also certainly older. It is possible that in ancient times they were as visible as those of Saturn.

It is believed that by bumping into each other, all the particles forming the rings will eventually be ejected from the orbit of the planet, or be swallowed by it. To last, the store of matter in Saturn’s rings needs to be replenished or they will eventually disappear.

The rings remain intact thanks to the multiple moons whose gravity keeps them in their course by retaining the particles.

Origin of the name

Some scientists believe that Saturn has been observed by humans since prehistoric times. In ancient times, the Greeks gave it the name Cronos (God of crops), perhaps because of its position in the sky corresponding to the time of harvest. The Romans give it the name of their God of agriculture: Saturn.

We also owe Saturn a day of the week: Saturday (saturday in English).

The climate on Saturn

It may seem incredible, but the climate activity of Saturn is much higher than that of Jupiter: strong winds can reach 1600 km / h against 600 km / h on Jupiter. To measure wind speed, scientists analyze the movement of cells in the atmosphere, as well as changes in cloud shapes.

Scientists believe that lightning is raging on Saturn, but it is impossible to observe at this time. There are also very powerful hurricanes which are constantly observed. At the South Pole, there is a hurricane measuring 8,000 km wide. If it took place on Earth, it would wipe out a large part of our planet!

Scientists wonder a lot about this violent wind which reigns on Saturn: the planet receiving little energy from the Sun, and itself producing little energy, it is rather astonishing.

Titan

There are currently 82 moons orbiting the planet, but there are probably many more. In 2005, Huygens, a spacecraft developed by NASA for the Cassini mission, visited one of them, Titan. This probe landed on the surface of this Moon, and revealed impressive images.

Scientists were struck by Titan’s resemblance to Earth: rivers, lakes, winds, dunes …

Specialists did not know whether the Huygens probe would land on a solid or liquid surface. It looks like she landed on a sticky surface, somewhere between solid and liquid, which is very amazing! This Moon fascinates scientists, because it has a composition that could be conducive to life …

The hydrocarbon (methane) resources present on Titan are phenomenal and could supply Earth’s energy needs for a very long time.

Enceladus

Another moon of great interest, Enceladus is a small world of ice and rock. Much smaller than our own Moon, yet it is the subject of much research. In 2005, we discovered a surprising activity on Enceladus: sources were constantly springing up there. They could be liquid water geysers. These geysers would rise in space several hundred kilometers due to the low gravity and absence of atmosphere.

Enceladus appears to be riven with geologically active faults with plumes of water soaring into space. It is believed that Saturn’s attraction to Enceladus creates frictions that heat the surface of Enceladus to result in these cosmic geysers.

Saturn’s outermost E-ring may have formed because of the Enceladus geysers.

Enceladus is completely covered with the ice fallen from its own geysers. The presence of all this ice, possibly water, suggests to scientists that microbial life may have developed there. Enceladus is a fascinating world for anyone looking to find out if extraterrestrial life exists in our solar system.

Cassini, mission to Saturn

Before the Cassini mission, our knowledge of Saturn was limited to observations from Earth, and a few overflights of space probes. But for more than a decade, the probe orbiting Saturn has studied the composition and temperature of the gas giant’s atmosphere.

Cassini has also enabled close-up observation of storms on Saturn, as well as other weather conditions that cannot be observed from Earth.

Although Saturn is best known for its beautiful rings, the planet itself is still a fascinating object of study. As large as 700 times the Earth, it is a veritable planetary monster. We may never be able to unlock all the secrets of this inhospitable planet, but thanks to Cassini, many of these secrets have been revealed.

A mysterious vortex

In the early 1980s, the Voyager probe flew over Saturn and revealed an astonishing geometric shape at the North Pole: a perfect hexagon. In 2006, the Cassini probe revealed that this hexagon is still present. At the time, this is a rather enigmatic object, because it does not move and always stays in place. This is a huge hurricane that may have been around for several centuries. Its diameter is approximately 32,000 km.

End clap for Cassini

Before taking its scheduled bow on September 15, 2017, the Cassini probe will not have stopped studying the gas giant and sending us spectacular pictures!

Internal structure

Saturn is divided into three zones: nucleus, larger intermediate zone of metallic hydrogen and finally molecular hydrogen.

Saturn is classified as a gas giant because it is mainly composed of hydrogen and helium. Thus, standard planetary models suggest that the interior of Saturn is similar to that of Jupiter, with a rocky core surrounded by hydrogen and helium as well as traces of volatile substances – also called “ice”.

The rocky core would be similar in composition to Earth, consisting of silicates and iron, but denser. It is estimated from the planet’s gravitational field and geophysical models of gaseous planets that the nucleus must have a mass ranging from 9 to 22 times Earth masses, reaching a diameter of about 25,000 km13. This is surrounded by a thicker layer of liquid metallic hydrogen, followed by a liquid layer of molecular hydrogen and helium which gradually turns into gas as the altitude increases. The outermost layer extends over 1000 km and is made up of gas. Also, most of Saturn’s mass is not in the gas phase because hydrogen becomes liquid when the density is greater than 0.01 g / cm3, this border being reached at the surface of a sphere corresponding to 99.9% of the mass of Saturn.

Saturn has a very high internal temperature, reaching 12,000 K (11,727 ° C) in its heart and, like Jupiter, radiating more energy into space than it receives from the Sun – approximately 1.78 times16 . Jupiter’s thermal energy is generated by the Kelvin-Helmholtz mechanism of slow gravitational compression, but such a process alone is not sufficient to explain Saturn’s heat production because it is less massive17. An alternative or additional mechanism would be the generation of heat by the “rain” of helium droplets in the depths of Saturn. As the droplets descend through the lower density hydrogen, the process would thus release heat through friction and leave Saturn’s outer layers depleted of helium. These descending droplets may have accumulated in a helium shell surrounding the nucleus. It is suggested that diamond showers occur inside Saturn, just like within Jupiter and the ice giants Uranus and Neptune.

However, given its distance from the Sun, Saturn’s temperature drops rapidly until it reaches 134 K (−139 ° C) at 1 bar then 84 K (−189 ° C) at 0.1 bar, for an effective temperature of 95 K (−178 ° C).

Astrology of Saturn, ruler of Capricorn

This planet illustrates the actions, the decisions to be taken, the concrete, the reflection, the events which will have a real consequence on the paths of life in the long term. This implies notions of prudence, rigor, taking a step back, obligations but also frustration and renunciation. Saturn is not always very popular in a horoscope because it can be synonymous with separation, emotional breakdown as well as professional. It is associated with the element Earth.

When Saturn has a positive influence, it echoes patience, the ability to organize, to plan, to be methodical in one’s actions. It illustrates wisdom and maturity.
With negative influence, the presence of Saturn is synonymous with loneliness, discomfort, unhealthy obsession, lack of imagination, restriction.
Saturn is the planet of Capricorn. It reflects their Cartesian temperament, their very important capacity for work, their honesty but also their obsessions close to mania.

Sources: PinterPandai, NASA Science, Space Facts, The Planets

Photo credit: Wikimedia Commons