Is Jupiter a Gas Planet?

Jupiter, Rock or Gas Planet? 

Jupiter, the fifth planet from the Sun and the biggest in our system, is often also known as the “Gas Giant“, since it is composed by liquid hydrogen and its atmosphere is made up of hydrogen (90%), helium (10%) and traces of other gases; for this reason Jupiter can be defined a gas planet and it is not characterised by any rocky surface.

Its gaseous condition can be related to the fact that the planet was not able to reach the critical mass to become a star.

Did you know that the majority of solar systems, in the outer space, are usually made of two stars instead of a single one?

However, some theories currently being verified by NASA Mission Juno, hypothesize the posibility, for Jupiter to have, or have had in the past, a solid core.

The presence and the extent of the magnetic and gravitational fields, will bring new data into this debate.

The shape is related to the gas planet rotation speed of one complete round in about 10 hours, meaning that in a Earth Day it is involved in 2,5 rotations.

This high speed makes Jupiter, and its gases, take the shape of an oblate spheroid.

Does Jupiter have an atmposphere?

Yes, even if there is not a precise separation like on Earth, Jupiter’s atmosphere has been defined by scientists as the layer above the point where the pressure measures the same as on Earth’s surface, 14.50 psi (1 bar or 0.9869 atm). 

It is composed by four sections: troposphere , stratosphere, thermosphere and exosphere; each one has been identified by specific pressure and temperature configuration.

 Like on Earth, the temperature decreases with the increase of height, to a minimum point; this particular value separates the troposphere from the stratosphere.

This boundary is also called tropopause and it is located about 30 miles (50 km) from the “surface”.

As we move out to the outer space, the pressure decreases its value as the layer of gases gets thinner; temperature, instead, slightly increases again until the height of about 200 miles (320 km).

Here, the temperature reaches the -99.67 °F (200 K, -73,15 °C) and this is defined stratosphere-thermosphere boundary.

Above this point, in the thermosphere, temperature grows and reaches its highest value of 1340.33 °F (1000 K, 726,85 °C) at an altitude of 621.37 miles (1000 km).

This is the boundary which defines the external section called exosphere.

The bottom parts of atmosphere, troposphere and stratosphere, host the famous Jupiter clouds and an haze layer.

The troposphere has an heterogeneous chemical composition and three clouds sections, with increasing pression and density values as we drop the considered height.

First, the upper clouds made of ammonia ice, located at the pressure range of 0.6 – 0.9 bar (8.70 – 13.05 psi); below this, at the pressure layer of  1 – 2 bar (14.50 – 29 psi), denser clouds made of ammonium hydrosulfide, (NH₄)HS, or ammonium sulfide, (NH₄)₂S; at the pressure of 3 – 7 bar (43.51 – 101.53 psi) , also water clouds are thought to exist.

There are no methane clouds as the temperature is too high for it to condense.

The water ones are the densest, having the biggest influence on the atmosphere turbulent dynamic: this is the result of the higher condensation heat and abundance of water, compared to ammonia and hydrogen sulfide.

In other words, oxygen is a more abundant chemical element than either nitrogen or sulfur in this gas planet.

Regarding the stratospheric haze layers, they reside above the main cloud layers.

They are made from condensed heavy polycyclic aromatic hydrocarbons or hydrazine; these are generated in the upper stratosphere from methane, under the influence of the ultraviolet radiation of the sun.

Jupiter’s thermosphere is located where pressures is lower than 14.50 psi (1 μbar) and demonstrates such phenomena as airglow, polar aurorae (below image) and X-ray emissions.

Ionosphere is formed by the layers of increased electron and ion density that exist whithin it.

The thermosphere and the exosphere at the poles emit X-rays.

From Jupiter’s magnetosphere arrive energetic particles that create bright auroral ovals, as you can see in the image above.

Jupiter aurorae are permanent in the atmosphere, while on Earth can be seen only during magnetic storms.

Does Jupiter have a surface?

Being a gaseous mass, scientists think that Jupiter does not own a solid surface, even if nobody actually ever verified by trying to walk there!

If you are really looking for a rocky surface, the core of the gas planet, whose existence is still in doubt, could be made of solid matter where you could try to have an exciting walk.

 

However, it is assumed that under the atmosphere made of 30 miles (or 50 km) cloud barrier, there are hydrogen and helium.

These ones are constantly liquefying, as pressure increases while moving in the direction of the center of Jupiter.

Under that layer, it is supposed to exist liquid metallic hydrogen and the thickness of this section should be about 25,000 miles or 40.000 km.

Going deeper, we could probably find the core, the innermost part of the gas planet.

Scientists are still trying to figure out its existence, as you will read below.

Does Jupiter have a core?

According to the majority of theories, Jupiter has a solid dense core composed of ice, rock and metal, aggregated at the beginning of our solar system by the gravity force, joining together asteroids and comets surfing in the area at the perfect moment, billion years in the past.

 The nucleus is made of diffuse core mixed into its mantle; its dimension is significant as it is characterised by a radius value between the 30% – 50% of the planet’s one.

An impact by a 10 times Earth trump planet or some particular conditions arisen during Jupiter formation in the surrounding nebula, could have led to the this nucleus condition.

After the formation of the core, due to its gravity, all the gases that we are able to see now have been captured in Jupiter’s atmosphere and still are prisoner of planet’s gravity (2.5 times stronger than Earth’s, local g=24.79m/s).

The temperature there would be 55,000 Fahrenheit (30.000 Celsius) and the pressure would reach out of mind values, because of the heavy layer of gases floating above.

However, according to a minority theory, the planet could have no core at all.

The hydrogen and the helium cooled and condensed from the large cloud in which the sun was born, in a heterogeneous way: some regions were denser and able to pull more matter until the planet was born.

This doubt is going to be solved by Juno Mission which will measure Jupiter’s gravitational and magnetic fields, revealing wheter the gas planet has a core.

By that measurement, and having eventually the knowledge of fields size, one theory will prevail on the other one.

To clear the situation, some scientists suggested another possibility considering that the core could have gone through time and now it is not there anymore.

It looks like you have reached the end of the article and you deserve a prize!

Have a look at these pictures of Jupiter.

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