top of page
  • Writer's pictureMehdi Hussain


Like many other people, for many years, I had a view that though Mars has frozen water on the poles in polar ice caps but it did not have water in the liquid form. Also, that water had flown on the surface of Mars a long time ago as the dried up water channels are visible on its surface even from the Earth. Like others, the belief was firm that there used to be water in the liquid form on the surface of Mars billions of years ago but now, it has evaporated and gone out in the space. Also, that some water might be present underground in the form of permafrost as well.

It was considered because of the extremely low pressure atmosphere on Mars. So, the result was, either it can be present in the frozen form or it became gas and left the planet. Why?

Evaporation & Condensation Equilibrium

You might know that water in the liquid form keeps on evaporating in the gaseous phase. The vapours in the liquid phase has a pressure to go out from the condensed phase into the atmosphere. When the external pressure is more than the vapour pressure of the liquid, they get condensed back into the liquid phase. There is an equilibrium which is achieved during this process. The boiling point of a liquid is the temperature at which the vapour pressure of the liquid becomes equal to the external atmospheric pressure. At that point the rate of condensation becomes lower than the rate of evaporation and all of the liquid is converted to gaseous form. On Mars, the atmospheric pressure is so low, that the boiling happens at the normal average temperature on the surface of Mars. Which means that as soon as water converts from its frozen state to the liquid state, it boils off.

Mars Polar Ice Cap

There’s another interesting fact. In a fixed volume system, conversion of liquid into gaseous state raises the atmospheric pressure in the system. As the atmospheric pressure increases the rate of condensation increases and the overall evaporation decreases and an equilibrium is achieved. When we increase the temperature, the vapour pressure increases which increases the evaporation rate. The increased evaporation increases the atmospheric pressure and eventually the equilibrium is achieved once again. Even at the boiling point, the evaporation increases the external pressure which eventually creates condensation of the liquid in gaseous form. Eventually, an equilibrium state is reached.

The lower the external atmospheric pressure, the lower is the boiling point. Evaporation is a continuous process and does not require the temperature to reach to the boiling point for it happen. The liquid and gaseous form of water are in an equilibrium before the boiling point is reached. Unless there’s enough space available for the liquid to completely convert into gas, an equilibrium is achieved between vapours and condensed liquid at relatively higher pressure. We can assume that even if there's an extremely low atmospheric pressure and a very low boiling point, there must be an equilibrium which would be sustaining water in the liquid state on the surface of Mars.

On Earth, at a larger scale, water condensing or coming back as precipitation, in the form of rain or snow. On Mars, the evaporated water when it reaches the poles gets frozen and stays there on the poles. However, there is still a lot of water that must remain in the atmosphere in a gaseous state. Rain is not something out of the question either. The whole process can result in clouds, rain, snow, which eventually can result in mud pools or underground water reserves and water/mud channels.

Also, water on the poles under pressure becomes liquid and can travel under the surface only to come out from other places and evaporate. This creates long tunnels under the ground in which water and mud flows. Holes appear on the surface of these tunnels from which water evaporates and goes back into the atmosphere. Sometimes, mud comes out and flows from it while the water evaporates and the mud dries up. We take this as our starting point and compare few of the similar facts that we observe on Earth. Before going into it, I want to share why I am able to connect the dots here.

Large crater on top of a mud volcano in Balochistan, Pakistan on Earth

Mud flow in one of the volcanoes in Balochistan, Pakistan on Earth

I have been studying and exploring mud volcanoes on the surface of Earth for decades. I have mostly explored mud volcanoes in the Balochistan province of Pakistan. There are more than 100 mud volcanoes in that region, most of them are alive and oozing mud and gases. Also, I have studied the satellite imagery of all of these hundreds of mud volcanoes during this period.

Besides geology, I have been a student of astronomy, physics and chemistry. Logically, the planet Mars is not out of my focus. Thanks to NASA, ESA, JPL and other space agencies and Google, very detailed satellite imagery of Mars is now at our fingertips. I have been studying them very closely for some time and could relate few scientific facts to them.

After having done such studies of mud volcanoes, geology, physics, chemistry and other related sciences, when we take a look at the geography of Mars in the satellite imagery, interesting outcomes are seen.

In the satellite imagery of Mars, it is observed that there are following features that give rise to many questions

  1. Dried up water channels

  2. Underground tunnels with series of holes

  3. Lots of small craters

  4. Volcanoes with large craters on top

  5. Recent flow patterns

  6. Muddy patches

  7. Crater free chasmata

  8. Water erosion patterns

Atmosphere of Mars is very dynamic and it’s observed that there are frequent large scale sand storms. These are the storms that we have seen from far away engulfing large areas the planet. There must be smaller storms and strong winds as well throughout the year. It is evident from the patterns on the sand in some of the closeup satellite imagery.

Sand patterns on Mars due to strong winds

Dried up water channels

There are prominent water channels on the surface of Mars which appear to be dry. It is thought that water used to flow in these channels billions of years ago and has stopped flowing afterwards. Provided such a dynamic and windy atmosphere, wind erosion must be happening. Due to wind erosion over billions of years, the channels would have eroded and disappeared. Presence of these channels even today is a big question mark. The presence of these water channels today suggests that water has flown in these channels not very long time ago.

Dry water channels on Mars

There is also a possibility that mud flows in these channels instead of just the liquid water. Water gets evaporated and the mud is left. The settled mud created long depressions which resemble dried up water channels. There’s also a possibility that the flow was actually underground that created depressions on top of them.

Underground tunnels

Study of the mud volcanoes in Balochistan area of Pakistan showed that there are long underground tunnels / tubes and cave networks around the volcanic area. These tunnels are created because of the mud flows beneath the surface. These tunnels have a number of small and large openings on the surface as well. The top surface of these tunnels and cave systems make a terrain that we call mud glaciers. When we study the surface of Mars, a similarity is observed between the underground tunnels on Mars and the tunnels of mud volcanoes on Earth.

Underground mud tunnels in Balochistan, Pakistan on Earth

Underground mud tunnels in Balochistan, Pakistan on Earth

Underground mud tunnels in Balochistan, Pakistan on Earth

If they are what they look like, then there is a high probability that mud flow is happening under the surface of Mars that resulted in such tunnels with holes. Mud flow suggests that there is an underground water movement happening and there is liquid water present there. There is a possibility that these are lava tubes, as we see in some parts on Earth around the lava volcanoes, but the possibility of mud flow can’t be completely denied as well. If it's mud flow, then there's liquid water under the surface.

Underground tunnels on Mars with holes on the surface

Underground tunnels with holes

Lots of small craters

There are a number of craters on the surface of Mars. It’s thought that almost all of them are because of the impact of falling meteorites. However, there are patches with a large number of very small craters. They resemble the surface of custard after it gets cooled down. The small bubbles that come up on the surface of custard pop and leave a small crater. Similar crater formation is seen on the surface of Mars. In my view, such craters on the surface of Mars are not created because of an impact. Rather, they are created by the liquid water coming out on the surface and get evaporated into the atmosphere because of the extremely low pressure. The sand which is left behind is dried up to form a crater.

Craters on the surface of Mars

Craters on the surface of Mars

Craters on the surface of Mars

Dry surface of custard


There are few volcanoes which appear to be dormant. For example, Olympus Mons or Pavonis Mons. On top of these volcanoes lie large craters. It is believed that these are the lava volcanoes that used to spew hot lava. However, if we see the anatomy of other relatively smaller craters, it would be easy to identify that they are elevated from the rest of the ground. This suggests that they all are not impact craters but they are volcanoes. However, it is hard to say that they all are lava volcanoes. There is a possibility that they are mud volcanoes and they are active. Since, liquid water gets evaporated quickly, the activity is not very prominent. If that’s true that they are a big source of recycling the water back into the atmosphere.

Pavonis Mons on Mars

A crater on an elevation

Small volcanoes with craters

Dried up mud volcano in Balochistan, Pakistan on Earth

Recent flow patterns

There are places on the surface of Mars that show patterns very similar to the patterns we find on the mud volcanoes here on Earth. When mud flows out from a vent, it flows and gets dried up. On Mars, we see different shades of similar patterns which depicts the flow to be happening in different timings. Also, when we see similar patterns on Earth around mud volcanoes, they are not very old. They are no older than just a few years. By looking at these patterns on Mars, we can assume that it's mud flow and it's not very old. Absolutely not a billion years old.

Mud flow like patterns on Mars

Mud flow like patterns on Mars

Mud flow like patterns on Mars

Mud flow of a mud volcano in Balochistan, Pakistan on Earth

Mud flow of a mud volcano in Balochistan, Pakistan on Earth

Muddy patches

There are few places on Mars where large areas of the surface look like dried up mud. If liquid water existed on that surface billions of years ago, then due to wind erosion, the patterns would have gone away. Since, these patterns exist even today, we can conclude that they are not very old. Which means, liquid water came up to the surface of Mars not very long time ago or perhaps, it is affecting the surface even today.

Dried up mud surface on Mars

Crater free chasmata

There are deep elongated steep-sided depressions near equator on Mars called chasmata (singular: chasma), e.g. Hebes Chasma. Studying these chasmata reveals that they are almost crater free. If most of the crater formations are from the external impact of meteors, then chasma must have these craters in big numbers too, however, that’s not the case. Which means that a number of craters on the rest of the surface of mars are also not impact craters. They are formed by the underground mud activity. These depressions are a result of geological activity or water erosion. Since, they are already deep, there is no mud activity under them. Rather, mud and water ooze out from the side walls and hence, no crater is formed in them. This activity creates a different type of patterns than creating the craters.

A portion of Hebes Chasma on Mars

Closeup of a portion of Hebes Chasma - Crater free area

It should also be noted that these chasmata are present near equator. As there is a possibility that water moves from the frozen polar ice caps, towards equator, these chasmata seem to be the final destination of the liquid water which could not escape out from the vents through its journey from the ice caps to the equator.

Water erosion patterns

There are water erosion patterns which do not look billions of years old. Rather the sharp edges of the erosion patterns depict that they are very recent and have not gone severe wind erosion yet. Since, there are strong winds on the surface of Mars, if they were very old, the edges would have eroded.

Water erosion patterns on the surface of Mars


Considering the above relevancies, one may come to a point that Mars still has water in liquid form. Not only that, there exists a water cycle. Also, this cycle includes movement of water with the mud that comes out from the mud volcanoes. These mud volcanoes on Mars are even bigger than the volcanoes on Earth. There is a lot of mud volcanic activity going on there above and under the surface of Mars.

Underground tunnels along the shield volcano on Mars

The conclusion we derive out of it is that there seems to be a water cycle on Mars which is a bit different from Earth. On Earth, there are oceans of liquid water. Water evaporates and forms clouds which precipitates in the form of rain and snow on the land and this water flows on the land to reach back to the oceans. The cycle is in equilibrium and keeps going on for billions of years. However, on Mars, the water is underground. There is permafrost but also, at places, due to high ground pressure, it is in liquid form. It flows underneath along with the mud and comes out from vents and holes on the surface and evaporates into the atmosphere. This water is carried to the poles and gets frozen. Under the depths of frozen layers, this water liquifies and flows underground from the poles and the cycle continues.

Most of this claim is made by looking at the similarities between few of the features and phenomena on Earth and that on Mars, by comparing the satellite imagery. I must give a disclaimer that there is a probability of it to be wrong as this claim. This is all done without actually going to Mars. Truth will be revealed by the ground realities which we will see eventually by going there in future.

Mud glacier on Mount Mehdi Mud Volcano, Balochistan, Pakistan, Picture Credit: Syed Maaz

About the author

Mehdi Hussain, Picture Credit: Aslam Musaferzai

Mehdi Hussain is one of the co-founders and a director of Mareekh Dynamics, the company working on the engineering solution for the human habitation on Mars. He has been working in the space of astronomy, geology, physics and related scientific fields for decades. By formal education and profession, he is an engineer and a businessman.

Mehdi Hussain at a mud volcanic site, Picture Credit: Aslam Musaferzai

He has done extensive research on the mud volcanoes in the last 16 years. The research involved the most difficult trekking and hiking on the mountains situated in the remotest of the areas of Balochistan province of Pakistan.

He has also been doing practical astronomy for the last three decades. He is the president of Karachi Astronomers Society and also owns and runs a space observatory with the name of Kastrodome in Karachi, Pakistan.

The above article is based on his research on mud volcanoes and the study of the surface of Mars using satellite imagery.

22 views0 comments


bottom of page