In the clutter of the discovery of planets and their orbital characteristics been closely observed by many scientists and astronomers, there existed a planet which is sometimes visible in the sky as is the second largest planet after Jupiter. The sixth planet from the Sun, Saturn is observed as the brightest planet in the sky since the prehistoric times. Despite the fact that astrologically Saturn is associated with the principles of limitation, restrictions, boundaries, melancholy and practicality, it is the most beautiful planet seen in the night sky with its attractive rings and its ‘aurora’, that is, the curtain of lights that rise above the cloud tops and is sometimes seen at its poles. Of all our solar system’s planets, Saturn has the most spectacular ring system and is made up of seven rings with several gaps and divisions between them. Saturn orbits the Sun at a mean distance of 1,429,400,000 km and its equatorial diameter is 119,300 km. Saturn’s mass is around 5.68 x 10^26 kg.

When and how was Saturn first discovered?

Saturn often appears as a brightest star in the sky. In fact, it is one of the five planets, which are visible with unaided eyes. As mentioned, people have known this planet for thousands of years; therefore, it is impossible to know who was responsible behind its discovery. However, as science progressed, the first telescopic observation was made by Galileo Galilei in 1610. Initially, he was not able to distinguish the planet’s ring because of telescopic limitations and hence assumed that Saturn was triple-bodied. So, he thought, the planet might have two large moons or ears on both sides. Later in 1659, a more powerful telescope was used by a Dutch astronomer Chistiaan Huygens who proposed that Saturn was surrounded by a thin, flat ring. However, the division between the A and B rings were discovered by an Italian-born astronomer Jean-Dominique Cassini in 1675.

Where do we locate Saturn in the solar system?

With a polar diameter of 108,728 km which is about 90% of its equatorial diameter, Saturn is the fifth brightest object in the solar system. The reason behind its polar diameter being greater is due to its low density and fast rotation. Its average distance from the Sun is about 142,672,500 km, which makes it the sixth planet from it. Saturn has the second shortest day in the solar system as it turns on its axis once every 10 hours and 34 minutes. Saturn is wider at its equator, which is about 13,000 km, than between the poles. This is because the rapid spinning causes Saturn to bulge at its equator and flatten at its poles. It is a gas giant and its average radius is about nine times than that of earth.

How is the atmosphere of Saturn?

Saturn is the second largest planet and is made up of hydrogen and helium. It is more than 760 times the size of Earth. Also, it is more massive than any other planet except Jupiter which is approximately 95 times the mass of earth. The magnetic field of Saturn is about 578 times more powerful than Earth. Its atmospheric composition include about 96.3% molecular hydrogen, 3.25% helium, minor amounts of methane, ammonia, hydrogen deuteride, ethane, ammonia ice aerosols, water ice aerosols and ammonia hydrosulfide aerosols. In the equatorial region, winds in the upper atmosphere reach about 1,600 feet per second. However, the yellow and gold bands that are visible in the atmosphere are due to these super-fast winds, combined with the heat rising from within the planet’s interior. 

What is Saturn composed of?

As mentioned earlier, Saturn is big enough to hold more than 760 earths. Its core is about 10–20 times as massive as the earth. It is a gas giant and is mostly made up of hydrogen and helium. Its internal composition has many layers. It has a hot solid inner core of iron and rocky material, which is surrounded by an outer core that is composed of ammonia, methane, and water. The next layer is highly compressed, liquid metallic hydrogen. The next is followed by a region of viscous hydrogen and helium. The elements of hydrogen and helium are becoming gaseous near the planet’s surface and are merging with its atmosphere. 

What are Saturn’s rings?

Saturn has many rings around it. These rings are made up of particles of rock and ice. The size of all these particles vary from small grains in millimetre to a couple of meters in its range. These particles have extended thousands of miles from the planet, but the main rings are approximately thirty feet thick. All these main rings were named alphabetically as they discovered. They are known as C, B and A. Usually they are close to each other. The gap between B and A is around 4,700 km wide, which is known as Cassini Division. ‘D’ ring is the innermost ring and it is extremely faint. In 2009, it was revealed that, billons of earths could be fit within the outermost ring. 

Describe Saturn’s moons?

Saturn has at least 62 moons. Out of these 62 moons, 53 have been officially recognized as moons while 9 have been temporarily assigned the status of being a moon. They are:

  • Pan: Pan has been identified as being the moon closest to Saturn's surface. It was discovered by Mark R. Showalter in 1990, while analysing pictures sent back by the Voyager. We do not know much about it as it is so far. Pan was named after a god that symbolised woods, fields and flocks. It has a human body and head, horns and ears, and goat legs.
  • Atlas: It is the second of Saturn's moons and was discovered by R. Terrile in 1980. It orbits Saturn beside A Ring.
  • Prometheus: It was discovered in 1980 by S. Collins and a few others. It is an inner satellite of Saturn's F ring. It has been identified as being third closest to Saturn’s surface.
  • Pandora: It was discovered in 1980 by S. Collins. The outer moon of the F Ring is called Pandora.
  • Epimetheus: It is the fifth closest moon from the surface of Saturn.  It was discovered by Richard Walker first in 1966, and then again in 1977 by Stephen Larson and John Fountain. These three officially share the discovery. 
  • Janus: It was discovered in 1966 by the French astronomer Audouin Dollfus.  It is also the origin for the name of the month January.
  • Mimas: It was discovered by William Herschel in 1789. Mimas is associated with the Death Star in the popular film, Star Wars. That is the reason that the astronomers have given the name “The Death Star”.
  • Enceladus: It is the eighth satellite of Saturn. It was also discovered by William Herschel in 1789. In the solar system, it is the brightest moon.
  • Tethys: It was discovered by Cassini in 1684. It is seen as a giant ice cube in the sky. Scientists believe that it is pure water ice but they have convinced that at one point of time it was liquid.
  • Telesto: It was discovered by Smith in 1980. It is the tenth world orbiting Saturn. In comparison with all the other moons in solar system, it is the smallest.
  • Calypso: In 1980, it was discovered by Seidelmann, Pascu, Currie and Baum.
  • Dione: It was discovered by Cassini in 1684. It is the twelfth moon from Saturn. Out of all the other moons of Saturn, Dione has the maximum density.
  • Helene: It is the thirteenth satellite of Saturn. It was discovered in 1980 by Laques and Lecacheux.
  • Rhea: It was discovered by Cassini in 1672. Rhea is the second largest moon of Saturn.
  • Titan: Titan is the largest satellite of Saturn and it was discovered in 1655 by Huygens. Also, in our solar system, it is the second largest moon. It has larger diameter than the planets Pluto and Mercury as well as the Earth's moon. It has thick atmosphere as compared to that of the Earth.
  • Hyperion: It is Saturn's sixteenth moon. It was discovered in 1848 by Bond and Lassel. It is not in the shape of a ball and yet it is the largest object in the solar system. 
  • Lapetus: It was discovered in 1671 by Cassini. It is entirely made up of ice water.
  • Phoebe: It was discovered in 1898 by Pickering. Phoebe is four times far away than Iapetus from Saturn.
Which are the recently discovered satellites?

Some of the additional satellites have been discovered recently: S/2007 S3, S S/2007 S2, S/2009 S1, Urtur, Aegaeon, Anthe, Kari, Jarnsaxa, Greip, Tarqeq, Skoll, Loge, Hati, Hyrrokkin, Fenrir, Farbauti, Bestla, and couple of others. There is still only very little information available about these satellites.

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