Discovered in the seventeenth century, on 25th March, 1655, by Christiaan Huygens, who was a Dutch Astronomer of renown, Saturn is one of the most beautiful and enigmatic planets, distinguished by its rings and dozens of satellites. In this article, facts are explored, which will reveal the true nature of Earth's 'Gaseous' cousin.
Saturn's location is beyond Jupiter, in the Solar system. Both of them, along with Uranus and Neptune, are the gas planets. Here are some interesting facts about the planet's physical characteristics.
- It is the second largest planet after Jupiter and has a mass, which is 95.152 times Earth's mass, that is 5.6846 x 1026 Kg.
- It has an equatorial radius of 60,268 km, which is roughly about 8.55 times Earth's radius. The planet has a volume of 8.2713 x 1014 km3.
- It has a mean density of 0.687 gm/cm3, which is less than that of water. So, if you could find a big enough tank of water, Saturn would float in it.
- It is primarily made up of Hydrogen, along with small amounts of Helium and other elements like Methane, Ammonia, Ethane, Hydrogen deuteride, and Ethane.
- The planet is flattened at the poles and bulging at the equatorial region, which makes it an oblate spheroid in shape. That is why, Saturn's radius differs considerably at the poles and at the equator, by about 10%.
- At the equator, the acceleration due to gravity on the planet is 10.44 m/s2. It is just a bit more than the acceleration due to gravity on Earth, which is 9.8 m/s2. The escape velocity, that is the velocity that must be attained to escape the planet's gravitational pull, is 35.5 km/s.
- It has more than 200 observed satellites. Out of which 62 have regular fixed orbits. Titan is the largest of the planet's satellites. It is the only satellite which has an atmosphere and the only one which may have traces of life.
The inner structure of Saturn is not directly observable due to its thick gaseous blanket.
- Like Jupiter, it has a very small, dense, and rocky core, which is enveloped by Hydrogen and Helium. The core has a thick outer shell of metallic Hydrogen, which is then enveloped by Hydrogen and Helium.
- It is very hot from inside. Its hot interior reaches a temperature of 11,700° Celsius at the inner dense core. The mean surface temperature is about 134° Kelvin, that is about -103° Celsius.
- The quantity of heat energy, which the planet radiates, is roughly 2.5 times more than what it receives from the Sun. Most of this generated heat comes from heating of the core due to its compression under gravity. This phenomenon of heat generation due to gravitational contraction, known as Kelvin-Helmholtz mechanism, is also seen in Jupiter. Researchers are still probing alternative mechanisms that could explain the extra radiated heat.
The atmosphere on Saturn is nothing like that of Earth. Here are some facts about its atmosphere.
- It is primarily made of Hydrogen in molecular form (about 96.3%) and Helium (3.25%). The other marginally present elements are Acetylene, Ammonia, Methane, Ethane, and Phosphine.
- Clouds in the lower reaches of its atmosphere are made up of ammonium hydrosulphide and water. The upper level clouds are made up of ammonia crystals. It is an atmosphere, where Earth-based life wouldn't survive.
- The winds on Saturn are very strong, touching speeds up to 1800 km/hr.
- The layered atmosphere has a varying temperature range, from -23 degree Celsius to -153 degree Celsius.
- A year on this planet is equivalent to about 10759 Earth days or about 29.5 earth years
- It revolves around the Sun at an average speed of 9.69 km/s.
- Its closest distance of approach from the Sun is 1,353,572,956 km, while the farthest distance from the Sun is 1,513,325,783 km.
Saturn does have a magnetic field, which gave the first clues about the nature of its inner core. Here are some facts about its magnetosphere.
- The planet has a magnetic field, which is weaker than Earth. It is about 0.2 Gauss at the equator. The probable mechanism which creates the magnetic field is the dynamo created by the metallic Hydrogen layer around the solid core.
- Its magnetic field deflects the solar wind, which is a stream of high energy particles. One of its satellites, Titan, falls within the magnetosphere of the planet and, therefore, gets sheltered from the solar wind bombardment to some extent.
Its rings are what set it apart from all the other planets of the solar system. They are visible from Earth, with the use of high resolution telescopes. The rings probably formed from the crushing of some large satellite in the past.
- The rings are made up of gas and dust of sizes, varying from micrometers to many meters. They are mostly made up of ice, mixed with dust and chemicals.
- The rings are separated by gaps and form different bands. Most of them have an average thickness of 10 meters. The densest rings exist from 7,000 km to 8,000 km above the Saturn's surface.
- The estimated total mass of the rings is about 3 x 1019 kg.
- There are many 'shepherding' satellites within the rings. One of Saturn's moons, Rhea, has a small ring system of its own, around it.