Characteristics of Jovian Planets

According to the Solar Nebula hypothesis for the formation of the Solar System, the Solar system was nothing but a rotating mass of clouds, in the beginning. Primarily composed of hydrogen and helium, these clouds also had traces of heavier elements. As the speed of rotation of the cloud mass or nebula increased, heat and pressure began to develop within. This gradual build up of heat and pressure caused the nebula to explode. The center of the nebula, known as the protosun, was the region of highest temperature and the matter around this protosun was automatically reduced to the gaseous state. However, regions close to the circumference of the nebula were cooler and it was here that matter was found in the condensed form.

After the formation of the Solar System, the gravitational force of the sun gradually pulled the masses of higher density towards it due to which the planets made of rocks began to revolve in smaller orbits around the sun. The planets made of gaseous matter, however, moved to orbits farther away from the sun. Revolving in their orbits around the sun gave the planets a spherical shape. The immense gravitational pull of the large gaseous planets attracted matter scattered around the solar system and this matter, both rock particles and gases, began to revolve around these planets and thus the rings and many moons of these planets were formed.

Jovian Planet Characteristics

Jupiter, Saturn, Uranus and Neptune are the four jovian planets of the solar system. The density of jovian planets is less than that of the earth. These planets are mainly formed of hydrogen along with helium and compounds of hydrogen such as methane and ammonia. Uranus and Neptune are also called the 'ice-giants' because along with hydrogen and other gases, they are mostly made up of ice and water. If we compare terrestrial planets and jovian planets, we find that jovian planets have a large number of satellites or 'moons'. Uranus rotates at an angle of 97.77 degrees due to a tilt in its axis.

Let's have a look at some of the characteristics of jovian planets.

• Density of jovian planets is less as compared to that of the terrestrial planets.
• The jovian planets have very strong magnetic fields due to their high speed of rotation.
• Because the jovian planets are farther away from the sun, they have very low temperatures.
• The mass of the jovian planets is more than 10 times that of the Earth.
• Jovian planets have very small cores as compared to the terrestrial planets.
• Gas storms are a common phenomena on the surface of the jovian planets.
• The rings of the jovian planets are not solid but made up of particles moving around the planets.

In the table given below, you'll find the characteristic properties of the four jovian planets.

Planet	Name	Characteristics
	Jupiter	Mass: 1.9 x 1027 kg Density: 1.33 g/cm3 or 1/4th the mass of the Earth Distance from the Sun: 5.203 AU or 483.6 million miles Time of Rotation: 9h 55m 27s Radius: 71398 km Number of moons: 63 Time of Revolution: 11.86 years
	Saturn	Mass: 5.69 x 1026 kg Density: 0.687 g/cm3 Distance from the Sun: 9.539 AU or 886.7 million miles Time of Rotation: 10h 39m 22s Radius: 60330 km Number of moons: 47 Time of Revolution: 29.46 years
	Uranus	Mass: 8.66 x 1025 kg Density: 1.318 g/cm3 Distance from the Sun: 19.18 AU or 1784 million miles Time of Rotation: 17h 14m Radius: 26200 km Number of moons: 27 Time of Revolution: 84.02 years
	Neptune	Mass: 1.03 x 1026 kg Density: 1.638 g/cm3 Distance from the Sun: 30.06 AU or 2794 million miles Time of Rotation: 16h 7m Radius: 25225 km Number of moons: 13 Time of Revolution: 164.77 years

(AU stands for Astronomical Unit. It is a unit used for measuring distances in space.)

This was all about the characteristics of jovian planets. There have been several missions sent by the National Aeronautics and Space Administration (NASA) to explore the moons of these planets, including Titan which is one of the famous moons of Saturn. In future, mankind hopes to unveil the mysteries hidden in the farthest corners of our Solar System and beyond!