Why Is Neptune Denser Than Saturn? (Explained!)

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Neptune is denser than Saturn because of its composition. While both are made primarily of hydrogen and helium, the particles of these elements are packed together far more tightly on Neptune, giving the planet a greater density. In addition, Neptune’s environment has far more icy features that add to its mass and density.

Continue reading to discover why Neptune is the densest gas giant, and Saturn is the least dense. Plus, learn which of these planets would float in water.

Why Is Neptune The Densest Gas Giant?


Neptune is the furthest major planet from the Sun and the fourth largest. It is a gas giant, which means it’s makeup is mostly hydrogen and helium. The density of Neptune is 1.6 g/cm³ at the equator, which is just a little more than twice the density of water.

One explanation for the high density of Neptune is that, like Uranus, it has a higher proportion of rock in its interior than Jupiter to compensate for having a lower proportion of hydrogen and helium gas. Many scientists believe Neptune may have a large core composed of rocky materials that add to its density.

We class Neptune as one of the gas giants of the Milky Way, which means it is made mostly of gases. The composition of Neptune is mainly hydrogen and helium, with traces of methane, water, ammonia, and other hydrocarbons. It has a very thin atmosphere, primarily containing hydrogen, helium, and methane.

And Neptune holds the title of the densest gas giant in our solar system. This is because it has a higher density than Uranus, meaning Neptune’s molecular weight is greater than Uranus’s molecular weight. This means that there are more hydrogen and helium atoms in Neptune’s atmosphere than in Uranus’ atmosphere.

We can define the density of an object as the ratio of its mass to its volume. It is a property used in physics, chemistry, and engineering. You can calculate density by dividing the mass of an object by its volume.

A substance with a high density will weigh more for a given volume than one with a low density. This is because the atoms are packed tightly together, so there is less space between them, so they take up more room. The greater level of density an object possesses, the heavier it will be for the same size or volume.

Neptune is dense because it is made up of more ice than other gas giants, and water consists of tightly packed molecules. The density of Neptune is about 1.6 g/cm³, which is one of the highest among all the planets in our solar system, and that’s because Neptune has more ice and rock than other gas giants.

Why Is Saturn The Least Dense Planet?

Rings around saturn

Saturn is the second largest planet in our solar system, and sixth in line from the Sun. In addition, it is the least dense planet in our solar system, at only about 0.687 g/cm³.

The composition of Saturn is mostly hydrogen and helium; the lightest two gases in the known Universe. The planet also contains traces of water, methane, ammonia, and other hydrocarbons in its atmosphere.

A planet’s mass is determined by the amount of material it has: the more material, the more mass. Saturn is mostly made of hydrogen and helium gas, which are lighter than rock or metal.

Saturn has the lowest density of all the planets in the Milky Way because it has the lowest mass per unit volume. This is due to its composition and structure, which differ from other planets. The planet’s atmosphere consists of hydrogen and helium, which have low density. It also has low surface gravity, meaning it doesn’t pull as much on objects as other planets do.

Its core is the only part of Saturn with a greater density than water. It comprises a dense, hot, and mostly liquid mixture of hydrogen and helium with traces of other elements. Saturn’s core is the only place in the solar system where it can study what a gas giant’s inside looks like.

The study of Saturn’s core can help give insight into how Saturn and other gas giants formed, what forces shape their interiors, and how they might behave under different conditions.

Could Neptune Float On Water?

First discovered in 1846, scientsists named Neptune after the Roman god of the sea. Still, this planet has no solid surface, so it couldn’t float on the water it is named after.

If you place an object in water, the water molecules are attracted to the molecules on the object’s surface. This creates a force called buoyancy that pushes up on the object and keeps it afloat.

Hypothetically, the question of whether or not Neptune could float on water is based on its density. The density of Neptune is 1.6 g/cm3, while the density of water is 1 g/cm³. Since the density of Neptune is greater than that of water, it would most likely sink in water.

An item floats when the density of the fluid it is immersed in is less than that of the item. Saturn is the only planet that could theoretically float on water. The reason for this is because it is the only planet in the Milky Way which has a density that is lower than water.


Even though Saturn is far larger than Neptune, it does not have the same density as its icy counterpart. While Neptune’s density is 1.6 g/cm³, Saturn is only 0.687 g/cm³ which gives it the lowest density of the gas giants and the only planet in our solar system which could theoretically float in water.


How Big Is Saturn? – The Diameter, Mass and Volume Explained | Space

In Depth | Neptune – NASA Solar System Exploration

What is the reason that Neptune is more dense than other planets? – Quora

How Dense Are The Planets? – Universe Today

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