Gas planets: what are they, characteristics, images

gas planets, also known as jovian planets or giants, they are stars of Solar system, orbiting around the Sun. The main characteristic of these planets, in general, is their composition: they are made up of gases such as helium and hydrogen. Because of their composition, these planets are less dense than rocky planets.

The gas planets are:

• Jupiter

• Saturn

• Uranus

• Neptune

The gaseous planets of the Solar System are furthest from the Sun and are known as giant planets.

Origin of the gas planets

The gas planets formed approximately 4.6 billion years ago. The formation of these planets is directly linked to the formation of the Solar System. However, there is no fully accepted theory regarding this astronomical event. The most accepted theory today is called "solar nebula theory", formulated in 1644 by René Descartes and later reformulated by Pierre-Simon de Laplace in 1976.

Basically this theory indicates that the formation of the planets and the Sun it occurred through a solar nebula (interstellar cloud) that collapsed. Gravity was responsible for holding the particles from the collapse together. The large nucleus of concentrated particles gave rise to the Sun, and the other particles gave rise to the planets. The particles that remained closer to this concentration of matter had greater density – that's why they didn't move away – and gave rise to rocky planets. The less dense particles moved away from the Sun, giving rise to the gaseous planets.

Read too: What is Earth's atmosphere?

Main characteristics of gas planets

In addition to the characteristics common to gaseous planets, such as their composition and density, a solid core surrounded by gases and diameters greater than 48,000 km, these planets have characteristics private individuals. Look!

1) Jupiter

Jupiter is the largest planet in the Solar System.

Rotation	9 hours and 54 minutes
Revolution (movement of the satellite around the planet)	12 years
Diameter	142,984 km
Average temperature	-121°C
Volume	1,394 terrestrial volumes

Jupiter is the biggest planet in the solar system, therefore the largest gas planet. Regarding the order of the distance from the Sun, Jupiter is the fifth, being approximately 778,330,000 km away. Its volume is 1300 times larger than Earth's, but its mass is only 318 times larger. The planet has a rocky core, followed by a liquid layer and a gaseous layer filled with hydrogen, helium, ammonia and traces of water vapor.

The temperature on the planet can reach -100ºC, and its atmosphere is quite turbulent, causing something like hurricanes to occur. Its surface has colored spots, which form due to differences in chemical composition and temperature along the surface. The lighter patches are known as zones, and the darker patches are known as belts. Jupiter is formed by several rings, consisting of fine dust from rock particles. There are on the planet about 63 moons.

See too:rotation movement

2) Saturn

Saturn has a beautiful ring system.

Rotation	10 hours and 23 minutes
Revolution	29.5 years
Diameter	120,536 km
Average temperature	-125°C
Volume	835 terrestrial volumes

Saturn is known for its ring system, composed of ice. The planet is sixth in distance from the Sun, being approximately 1,429,400,000 km away from the star. Saturn's composition is similar to that of Jupiter. Furthermore, Saturn is the only planet in the Solar System that has a lower density than water.

The atmosphere of this planet is very dynamic, with strong winds. Its characteristic color is due to the presence of frozen ammonia. The temperature can reach -140ºC. With around 60 satellites, Saturn's best known is called the Titan. This is the only satellite in the Solar System that has an atmosphere.

Read too: Planet Earth - general data, characteristics, origin

3) Uranus

Uranus has a greenish color due to the presence of methane in its atmosphere.

Rotation	17 hours and 52 minutes
Revolution	84 years old
Diameter	51,118 km
Average temperature	-193°C
Volume	64 terrestrial volumes

Uranus is the seventh planet in distance from the Sun, being approximately 2,880,900,000 km away. The planet was discovered in 1789 by William Herschel, a German astronomer. Despite the similarities to Jupiter and Saturn, the Uranus composition it differs by the presence of other elements such as ice, carbon, silicon and oxygen. The planet's core is rocky and surrounded by a liquid layer composed of water, methane, ice and ammonia. Uranus' atmosphere is also made up of methane, which gives it a bluish color.

Uranus' atmosphere also differs from that of Jupiter and Saturn in that it is less dynamic. In addition, its tilt makes the planet pass to 42 years without lighting. It is also formed by several rings and satellites, having a total of 27 satellites.

4) Neptune

Neptune is the last planet in the Solar System and is known for its blue color.

Rotation	16 hours and 11 minutes
Revolution	164 years old
Diameter	49,492 km
Average temperature	-193°C
Volume	59 terrestrial volumes

Neptune it is the last planet in the Solar System, the eighth in distance from the Sun, being about 4,504,300,000 km away. The planet was discovered in 1846 by Ler Verrier, a French mathematician and astronomer. Much like Uranus, Neptune also has an atmosphere full of gases, like methane, which gives it a bluish color. However, unlike Uranus, Neptune's atmosphere is quite agitated, with strong winds and hurricanes.

The temperature on the planet can reach -218ºC. In addition, it has a ring system and 13 satellites. The best known satellite is called Triton and has a peculiarity: it has volcanic activity that takes liquid nitrogen to its exterior.

Does a gas planet have soil?

When we talk about the composition of gaseous planets, we sometimes question the possibility that there is a solid layer. According to astronomer Thaisa Bergmann, from the Federal University of Rio Grande do Sul, although these planets are surrounded by chemical elements in the physical gaseous state, in its outer layers, and in the liquid physical state, in the innermost layer, it is estimated that, at about 20% of the radius of the planets, there is the presence of metallic material, in a smaller quantity, configuring a kind of “solid surface”.

What is the difference between rocky planets and gaseous planets?

Rocky planets have less mass and greater density. Gas planets, on the other hand, have greater mass and lower density. This is due to the composition of these planets. As already said, gas planets are formed by gases, and the rocky planets, by rocks and heavy materials such as iron and silicates.

Also, rocky planets are closer to the Sun, and gaseous planets are further away. Another feature that sets them apart is the presence of satellites. Rocky have few or none, and gaseous have a large number of natural satellites.