Why Second Choice Is Mars? Ask the Astronomer | ScienceMonk

Mars is the nearest one that sustains living characteristics. If we find any lifeforms symmetric to those that exist on earth, then they might tell us how life originate on earth. If we find any civilization more advanced than us then we will be able to learn from them.

Do you know why we are chasing Mars? Why we are looking for another planet? Why only Mars? Ah! Lots of questions. Let’s figure them out.



First Thing First, Why Do We Have To Look For Life Outside The Earth?

So, the answer is the way we are treating our mother planet and the pandemic outbursts that we are facing right now means it may not be able to support life in the far future. As you can see, we are able to change the environment here, unfortunately, would be able to change the environment there too. So, if we find a planet nearby that can support life, it would be easy to migrate and reproduce life there.

The Second Question Is Why Mars?

Mars is the nearest one that sustains living characteristics. If we find any lifeforms symmetric to those that exist on earth, then they might tell us how life originate on earth. If we find any civilization more advanced than us then we will be able to learn from them.

Scientists have been trying to explore the possibilities of life in our solar system. The red planet, Mars has received the most attention. There were many rover missions to read that planet in recent decades. The total count to 56 mars missions so far, of which 26 have been successful. The prominent ones are from NASA.

Credit: NASA

List Of Major Missions To Mars:

  1. Viking 1
  2. Sojourner
  3. Opportunity
  4. Rosetta
  5. MarCO

Major Missions Coming In The Future:

  1. Mars 2020
  2. Tianwen-1
  3. Mangalyaan 2
  4. ExoMars 2022

To understand what potential mysteries the Martian atmosphere and surface hold to sustain life, we have to look at its past.

What Are The Human Requirements That Must Be Fulfilled By Mars?

  1. Water
  2. Oxygen
  3. Pressure
  4. Temperature

From the early times, the Homo sapiens have nourished their descendants near the rivers. Water has been an important factor to keep humans alive.

Around 17 million years ago, it had been found that some meteorite hit the Mars surface and created an impact crater. The impact was so strong that due to the intense shock wave, one of the Martian rock probably blasted off in space and kept wandering in the solar system.

After that, 13000 years ago, the rock named Allan Hills 84001 was attracted to earth and impacted it near Antarctica in December 1984 by American meteorite hunters from the ANSMET project. This meteorite was passed on to NASA as a meteorite for sample studies.


In 1996, a twist came when NASA declared that this rock was not an ordinary meteorite but it’s a rare sample descended directly from Mars. On careful analysis, it showed some structures which are probably traces of life from Mars!

This startling announcement caught up public interest and all nations started puzzling over sending missions to Mars. After that, this started the race to Mars by various space agencies around the globe, blasting multiple missions to Mars.

Life on Mars has eluded us for the past so many years, but now we have confirmed that there indeed was water on Mars.

Why We Aren’t Able To Find Life Yet?

The main reason for not finding water and maybe life on Mars is that the atmosphere there is very thin as compared to Earth. The atmospheric pressure on Mars is less than 0.01 times that of Earth’s.

Due to this very low pressure, the retention of water on the surface of Mars in liquid form is not possible. It quickly evaporates. One of the most striking features is that the atmospheric pressure at the Mars surface is very close to pressure for the Triple Point of water.

The triple point is the minimum pressure at which liquid water can exist. This is very interesting since a small variation in pressure, can make it possible for water to exist and it will result in abundant liquid water. However, at present, the pressure is not sufficient to hold water in liquid form.

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If we look at the composition of the Martian atmosphere, we see that it contains 95.32% of the CO2, 2.6% of molecular nitrogen, and 1.9% argon. It also contains traces of water vapours and oxygen.


Since we know that CO2 is a good candidate for causing the greenhouse effect. It means that heat flowing away from the planet can be trapped in the atmosphere and will help to retain it on the planet. Since CO2 is a good greenhouse gas and abundant on Mars, then it should be able to heat up the atmosphere as well as the surface. Why does it not do so?

The answer is found if we look closely at other parameters. The temperature of a planet does not depend only on the composition of the atmosphere but also on the atmospheric density, water content, tilt, and eccentricity of the orbit. Several other parameters may also affect, but these are the major ones.

The atmosphere of Mars is thin and there is no sea or large water source on the surface. The orbit is also more elongated as compared to Earth and hence the seasonal variation of temperature is also severe. 

The day time and night time temperatures vary over 70°C. With such extreme variations in temperature, is the planet Mars really habitable?

Why Studying The Present And Past Atmospheric Conditions On Mars Important?

We have discussed in detail the present atmosphere. And by the study of ALH84001, it was discovered that there was life before and will there be life possible in the future. Both the questions have to deal with what was there in the past and what will be there in the future.

We now believe that once upon a time Mars had a thicker atmosphere with abundant water. The water beds on Mars are remnant proof of the existence of flowing water. At some point in time, the atmosphere suddenly changed and thinned. Many gases escaped and CO2 became dominant. Efforts are ongoing to find how long the thick atmosphere existed and the answers may be found in upcoming missions.

Can We Transform The Martian Atmosphere? Terraforming Mars? It ain’t easy.

The process of transforming Mars into second Earth is called “Terraforming”.

The idea of transforming Mars is not new. Every second scientist has been thinking the same for years. We know that Mars does contain trapped carbon dioxide and the atmospheric pressure on the surface of Mars is very close to the triple point of water.

So if we are able to increase the pressure on the planet, then there may be a chance that water can exist on the planet in the future. Also, if we increase the total content of CO2, then the greenhouse effect may further increase leading to better conditions to stay on the planet.

But all this procedure of terraforming would take 100 years to execute. The hidden reservoir of carbon dioxide won’t be easy that easy to catch.

But where would we get the CO2 from? The answer is that there is a lot of CO2 trapped in the polar caps of Mars and also trapped along with various minerals near the soil. Now if we are able to get hold of this entire CO2, then we can trigger a mechanism and release this CO2 to the atmosphere. The question was how much CO2 will be found. NASA mission Mars Reconnaissance Mission, Mars Odyssey, and MAVEN data were used to study the problem.


For the polar caps region, the scheme could spread dust on the caps to absorb more solar radiation. Else we can use explosives to evaporate the caps and CO2 will be released into the atmosphere. If entire caps are melted to get maximum CO2, the pressure will increase to double the current pressure.


To get the CO2 trapped near the soil, we can burn the soil. Imagine, that we are mining up to the depth of nearly 100 meters and heating the entire surface of Mars. This will help release the gas into the atmosphere. The Rover data from earlier missions predicted the mineral distribution around the surface.

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Based on these estimates, it was concluded that this herculean task of mining all around will increase the pressure to 5% of Earth’s pressure. So, if we succeed in doing all these complex things, we will be able to raise the Martian pressure from the present value to 610 Pascal (or 4.57 mm-Hg) to 7092 Pa (or 53.2 mm-Hg).

Yet, this is just 7% of Earth’s pressure whereas, at the location of Mars for water to survive freely in liquid form on the surface, nearly the same pressure as on Earth is needed. Hence, it was concluded that even if we are able to squeeze out entire CO2 anywhere on the surface of Mars and are able to release it in the atmosphere, the exercise would still not help us gain favourable conditions on the Martian surface.

Apart from finding the second Earth in the vast space, every scientist would suggest you make Earth, the Earth.

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