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Mars Vs Neptune [How Do The Planets Differ?]

Is there life on Mars? We are currently of the opinion that there isn’t. Is there life on Neptune? Again, no, based on our current understanding. This is one thing that Mars and Neptune both have in common. But what about their differences? Well, they don’t share the same distance from the sun, as Mars is the fourth planet from that big ball of fire and gas, whilst Neptune is the eighth from it. But what else apart from this? Are these planets more different than they are similar? And why do they exist? Today, I am going to be answering all.

So, what are the main differences between Mars vs. Neptune? The main differences between Mars and Neptune are to do with their variations in size, orbit, chemical compositions, and temperature as well as many other interesting characteristics and processes. Neptune is the bigger planet, but Mars is the warmer planet on its surface (although Neptune is hotter at its core). Mars is a terrestrial planet, whereas Neptune is a gas giant. And Mars takes several hundred days to orbit the sun, whereas Neptune takes several decades to complete the same orbit pattern.

Let’s continue to explore, shall we?

What Are The Differences Between Mars And Neptune?

Mars and Neptune share differences when it comes to their size, orbit, chemical composition, temperature, number of moons, number of rings, axel tilt, rotation time, aesthetic, and wind speed.

Alright, so there’s quite a lot to split Mars and Neptune. Plenty of facts, characteristics, and processes to talk through.

So, without further ado, let’s get into it!

Size and Mass

The planets of our solar system, The Milky Way, come in a variety of sizes. There is always a clear difference between any comparison, even if, of course, some margins are bigger than others.

So, what’s the comparison like between Mars and Neptune? Well, Neptune is clearly the bigger planet. 

Neptune has a diameter of 49,244km, which is much bigger than Mars’ diameter of 6,779km. 

Neptune has a surface area of 7.618 billion square kilometers. Again, clearly bigger than Mars’ surface area of a mere 144.8 million square kilometers. 

And finally, Neptune has a mass of approximately 102,000,000,000 trillion metric tons. This is much heavier than Mars, which weighs approximately 642,000,000 trillion metric tons.

So, we now know that Neptune is the bigger planet, but where do these planets rank against the other planets of our solar system when it comes to size?

Well, these figures place Neptune as the fourth biggest planet, smaller than Uranus, Saturn, and Jupiter. Mars, on the other hand, is the seventh biggest planet in our solar system, only bigger than mercury.

Orbit of the Sun

Neptune is the eighth planet from the sun, and Mars is the fourth planet from the sun.

Does this play a part in the differences between these two planets? It certainly does! It impacts how long it takes for the planets to orbit the sun.

Mars is the closer of the two planets to the sun by quite some distance. It, therefore, takes much less time for it to orbit the sun, just once, than Neptune does. 

Mars takes about 687 days to orbit the sun.

Neptune, however, takes a whopping 165 years to orbit the sun, the longest time out of any planet in our solar system.

Chemical Composition

In our solar system, there are two types of planets to be found. These two categories of planets are gas planets and terrestrial planets. 

Neptune and Mars differ here once again. 

This is because Neptune falls into the gas giant category. A gas giant is a planet mainly composed of gasses, funnily enough. Two of the primary gases found on gas giants are hydrogen and helium. 

Neptune is joined in the gas giant category by Uranus, Jupiter, and Saturn.

Mars isn’t a gas giant. Instead, Mars is a terrestrial planet. Terrestrial planets are planets composed primarily of silicate rocks or metals. Mars, specifically, is predominantly composed of iron, nickel, and sulfur. 

Mars is joined in the terrestrial planet category by Earth, Mercury, and Venus.


Two different temperatures are to be analyzed when making this comparison between Neptune and Mars. 

The first is the measurement of how warm a planet is on its surface and in its atmosphere. The second is how warm a planet is at its core.

Mars is warmer than Neptune on its surface, with a temperature of approximately -88 degrees Fahrenheit (-67 degrees Celsius). Neptune’s surface is much colder, measuring at approximately -220 degrees Fahrenheit (-364 degrees Celsius). 

One of the reasons Mars is warmer on its surface is that it’s closer to the sun than Neptune. Therefore, the rays of sunshine that reach Mars are stronger and warmer than those that reach Neptune.

The second measurement to be analyzed is core temperature.

When it comes to core temperature, Neptune is warmer than Mars. It has a core temperature of approximately 9212 degrees Fahrenheit (-5100 degrees Celsius) Mars’s core is much cooler at 2462 degrees Fahrenheit (1350 degrees Celsius)

Gas giants tend to be warmer at their cores than terrestrial planets.

Number of Moons

Both Neptune and Mars have moons. 

Mars has two moons, whereas Neptune has an impressive 14 moons orbiting it.


Neptune has rings, but Mars doesn’t have any!

Neptune’s rings mainly consist of asteroids, comets, and even shattered moons. 

Axel Tilt and Rotation

Planets tilt at different degrees. 

Mars has an axial tilt of 25 degrees compared to Neptune’s pretty similar 28 degrees.

The two planets also differ when it comes to how long it takes for them to rotate once on their axes.

Mars takes 24 hours to complete one rotation of its axis. 

Neptune is even quicker, rotating once on its axis in 16 hours.


Mars is a vivid red, while Neptune is a deep blue, similar to Uranus. 

Wind Speed

When it comes to winds, no one is faster than Neptune.

The wind speeds on this planet reach an impressive 2,000 km/h. This is much, much, much faster than the winds on Mars that only reach as fast as 113 km/h.

What Are The Similarities Between Mars and Neptune?

Mars and Neptune share similarities when it comes to orbit pattern, and shape, the fact that they both have hotter central cores, multiple moons, and a gravitational pull, they cannot support human life, and humans are yet to visit either of them.

Although they are vastly different, Neptune and Mars are the same in some aspects.

Now it’s time to explore the similarities between these two mesmerizing planets. 

Orbit Pattern

Mars is quicker to orbit the sun than Neptune is. But they both share the pattern through which they orbit the sun.

Mars and Neptune both have circular orbits of the sun.

Both are Spherical

Planets come in different sizes, but they come in the same shape.

So both Neptune and Mars are both spherical in shape.

Both Have a Hotter Central Core

Both of these planets share the fact that their core temperatures are warmer than their surface temperatures.

But then again, this is pretty much the same for every planet in our solar system. 

Both Have Multiple Moons

They both have moons. But do you know what else is interesting? They both have multiple moons!

Mars has two moons, and Neptune has 14.

Gravitational Pull

Mars and Neptune are objects that both possess a gravitational pull force.

This force influences their interaction with the rest of the universe.

Their gravitational pull ensures that their moons continue to orbit them. For Neptune specifically, this force also keeps their rings in close proximity to their orbit.

Another difference worth pointing out is that their gravity strengths vary. Neptune’s gravity is measured at 11.15 m/s². This is clearly much, much, much stronger than Mars’ gravity of 3.721 m/s².

Can’t Support Human Life

We wouldn’t be able to live on either of these two planets. There are 2 key reasons for why this is so.

First of all, there isn’t any oxygen on either Mars or Neptune. We, humans, need oxygen to breathe, but I’m sure/hopeful that you knew that already. 

Secondly, our bodies aren’t designed to survive the incredibly hostile temperatures found on both of the planets.

So neither Neptune nor Mars can support and host human life. Best not to plan a trip anytime soon.

Humans Haven’t Visited

Even if you wanted to take a trip to Neptune or Mars, you couldn’t.

At the moment, humankind is unable to travel to Mars and Neptune.

The technology to overcome the obstacle, that is, the vast difference between Earth and these planets, is yet to be invented.


So, Mars and Neptune are unique in their own different ways.

But then again, so is every planet in our solar system.

Our home planet, Earth, is arguably the most unique of all.

But what we all have in common is that we’re part of the same solar system, The Milky Way!!

Other planetary comparisons you may want to see: