Monday, September 13, 2021

Chatusutra_Loksatta_03: Conquest of Mars?

  Since January 2021, I am writing on Environment and Science in the 'Chatusutra' weekly column of Loksatta, a Marathi language newspaper. This weekly series contains four different themes being written by four different authors in a four-week cycle. My first article was published on the second Wednesday of the year, and thereafter my articles are coming every four weeks. One of the request from the readers has been to provide English translations for those who are not able to read Marathi. Meera Rotti took on the task to do this, and therefore I am launching this monthly mini-series. Every month, I will post the English translation of one article in the same chronological order that the Marathi articles have been published in Loksatta. 

Links to previous post: 

SUSTAINable Life: Chatusutra_Loksatta_01: Is Human A Virus? (samuchitenvirotech.blogspot.com)

SUSTAINable Life: Chatusutra_Loksatta_02: Battle of India's Survival (samuchitenvirotech.blogspot.com)


03. Conquest of Mars?

The original Marathi article published on 10 March 2021 can be found HERE.  


World-renowned innovator Elon Musk is dead set on colonizing the Mars in the coming few years. Recent successful landing of NASA’s Perseverance Rover on the Mars has led to a steady inflow of images and other information about the surface of our neighbouring planet. This is rapidly fueling the debates around human colonization of Mars. For Musk’s supporters, settling on other planets is the obvious next milestone on the path of technological progress for humans. Before we think about colonizing Mars, lets first understand the foundations of human settlements on the earth.

Current human civilization on the earth is based on the history of about 4.5 billion years. The last ten to twelve thousand years have seen a significant interference by humans in the natural system of the earth. In 2009, a Swedish researcher Johan Rockstrom put forth an important concept. He demonstrated that, to sustain human life on the earth, humans have to stay within the limits of nine natural systems of the earth. This clearly implies that these nine systems, or their alternatives, are also required to be established on the Mars to support life there. Let’s take a look at some of these systems, and the possibility of their existence on this neighbouring planet.

Humans must respect these planetary boundaries in order to sustain themselves on Earth. However at least three of the boundaries have already been crossed. 

The bio-diversity of the earth not only helps us in meeting our basic survival needs, but is also crucial in supporting some of our metabolic activities. For example, our intestines are home to many living micro-organisms. They play a vital role in converting food into nutrients. They are one of the first single-cell organisms that evolved on the earth, whereas we humans are one of latest additions to the living beings of the earth. Can the planet, which could not enable evolution of any form of life, sustain human life without any support from other living beings? In case we succeed in creating an alternative ecosystem, will it be possible for us to maintain its equilibrium?

Another key system that supports our life here on the Earth is the atmosphere of the Earth. For long sustained existence of humans on it, it is important that the three factors remain intact – the delicate equilibrium of mixture of atmospheric gases, layer of ozone in the topmost part of the atmosphere, and quality of air in the lowermost part of it where we reside.

In the past 4.5 billion years, earth’s atmosphere has undergone multiple transformations. The oxygen that was extremely low in the beginning of the evolution of life rose up to 21% thanks to the evolution of photosynthetic bacteria, and also lead to ozone layer formation in the outer layer of the atmosphere. The current state of the atmosphere is conducive for the entire living world on the Earth, and the equilibrium of this living world has been regulating the chemical equilibrium of the atmosphere. Carbon dioxide, which is just a few hundred parts per million of the atmosphere, maintains an adequate temperature on the earth to support life, and also enables production of food for us through the carbon-cycle. Moisture in the air is important to drive the hydrological cycle that provides us the water. And then there is oxygen gas without which we cannot breathe. Effects of imbalance in the atmosphere are now visible to us, the manifestations of which range from local air-pollution to global warming. If humans are going to be the only living specie in the artificial environment of the Mars, then to maintain its correct chemical balance, tremendous amount of energy will have to be expended.

The ozone layer present in the stratosphere protects us by blocking the harmful ultra-violet radiations of the sun. Mars does not even have any atmosphere, and hence these radiations reach its surface, totally unhindered. There is no atmosphere around Mars because it does not have its own magnetic field. Earth’s magnetic field not only protects its atmosphere from being blown away, but also from the cosmic radiations by deflecting them. Hence, humans on Mars will also have to work towards creating a system to protect themselves from the sun’s UV radiations as well as the cosmic radiations. Needless to say, we need to expend more energy to maintain such a system.

Well, one more aspect is worth mentioning in this context. We have evolved under the atmospheric pressure on the earth. The weight of the atmosphere we literally carry over our shoulders is also a key factor in maintaining our health. The absence of this very weight causes loss of bone density, loss of muscle strength in the astronauts who spend long time in space. Settlers of Mars will have to face this issue as well.

There are two more issues closely related to the water which support human life on the Earth.
Water first appeared on the earth during its nascent stage as a result of asteroids bombarding the Earth. About 70% of earth’s surface is covered by oceans. Even if the biosphere evolved from this very salt water, only fresh water can sustain humans. Most of the fresh water on the Earth is in the frozen form. We can directly use water available only from rivers, streams, creeks, lakes, wells etc. Water in these sources gets replenished through the water cycle. Water does not exist on Mars, so this too needs to be generated through chemical processes expending energy, and will therefore warrant extremely cautious consumption.

Increasing levels of nitrogen and phosphorous in our oceans, and resulting increased acidity is not only disrupting the equilibrium of the marine life, but is also indirectly affecting the earth’s weather cycle. The main cause of this pollution is the excessive use of nitrogenous and phosphorous fertilizers used in our food production. These chemicals enter the waterways and end up in the oceans. We have not yet succeeded in producing enough food for all without polluting the natural systems. Farming on Mars, and consistently produce food there is going to be even more challenging and energy-intensive task.

Natural ecosystems that are free from human interference play a vital role in sustaining our existence. As they shrink up making way for farming, animal-rearing, mining, industries, urbanization etc., we lose on the free-of-cost ecosystem services that we get from the them. For example, if there is a flowing river in the vicinity of a human settlement, domestic sewage water let into it after rudimentary treatment will not cause any harm. In fact, some organic matter from this water provides food for the organisms in it. However, if on one hand the density of population goes on increasing, and on the other hand, construction of dams causes the reduction in the flow of water in rivers, then separate systems need to be set up for processing of waste water. Many of the substances created by us (e.g., plastics) are spreading as waste in the nature. This too has long-term effects on the natural ecosystems, and lead to many challenges. Waste-water processing and recycling of waste materials will also be crucial on Mars, and also prove to be highly energy-intensive.

Mars-dwellers will have the Sun as the only source of energy. Technological development on the Earth was largely fueled by coal and petroleum. Dead biomass got buried under the surface of the land, and transformed into extremely energy-dense mineral fuels. Since Mars has not sustained any form of life, there are no fossil fuels underground on Mars.

In short, origin and survival of human life is dependent on every aspect of this prolific, fertile planet. We still have not completely realized the complex interrelationship between us and the various natural systems on the Earth. If we are not able to control the climate change and degradation of bio-diversity now, sustaining life right here on the Earth will also become an increasingly challenging task. Establishing and sustaining life on a planet devoid of any natural system that supports life; is going to be an even more challenging a task. 

 

Author: Priyadarshini Karve

English Translation: Meera Rotti