The vastness of space has always intrigued humanity. From ancient stargazers to modern scientists, the idea of exploring and settling other planets has captivated our imagination. Among the celestial bodies within our reach, Mars, the red planet, stands out as the most viable candidate for colonization. Its proximity to Earth, geological similarities, and potential resources make it a prime focus for space exploration and habitation. But can Mars truly become our next home? Lets try to find the answer to this question.
Mars is the fourth planet from the Sun and Earth’s closest planetary neighbor after Venus. At its closest, Mars is approximately 54.6 million kilometers away. This proximity, though vast by terrestrial standards, is manageable with current and developing space technologies. Unlike Venus, whose surface conditions are inhospitable, Mars offers a more temperate environment for exploration. Mars shares several features with Earth, making it a more plausible candidate for habitation than other planets or moons. A Martian day (or sol) lasts 24 hours and 37 minutes, close to Earth’s 24-hour cycle. Mars has a tilted axis, resulting in seasons similar to those on Earth. The polar ice caps on Mars contain frozen water, a crucial resource for sustaining life. Mars is believed to harbor resources that could support human life and technological development. These include water ice, which can be converted to drinking water, oxygen, and hydrogen fuel. The planet’s surface also contains minerals and metals that could be mined for construction and manufacturing purposes.
Internal structure of Mars
Crust
The crust of Mars is significantly thinner compared to Earth’s, with an average thickness ranging from 24 to 72 kilometers. It is primarily composed of basaltic rock, formed from volcanic activity that occurred billions of years ago. Unlike Earth, Mars lacks tectonic plate activity, which has allowed its surface features to remain relatively static over geological time scales. The Martian crust consists of silicates, basaltic lava, and iron-rich minerals. Ancient impact basins, vast plains, and volcanic formations like Olympus Mons can be observed on Mars. High concentrations of sulfur and chlorine, are indicative of its volcanic origin.
Mantle
The Martian mantle lies beneath the crust and is composed primarily of silicate minerals rich in magnesium and iron. While it shares similarities with Earth’s mantle, Mars’s mantle is cooler and less dynamic due to the planet’s smaller size and lower internal heat. Its thickness has been estimated to be around 1,560 to 1,800 kilometers. There is lack of active convection, contributing to the absence of plate tectonics.
Core
The core of Mars is thought to be partially liquid, composed mainly of iron, nickel, and sulfur. Seismic data from NASA’s InSight mission has provided evidence supporting this hypothesis. The radius of the core is approximately 1,700 kilometers. It has high sulfur content, making it less dense than Earth’s core. Mars lacks a global magnetic field, suggesting a solidified outer core or weak convection currents.
Surface features of Mars
Mars boasts a diverse array of surface features shaped by volcanic activity, wind erosion, and impacts. It has Olympus Mons which is the tallest volcano in the solar system, standing at 21.9 kilometers. Along with this, it has tharsis region which is home to multiple massive shield volcanoes. It has a vast canyon system stretching over 4,000 kilometers. It also shows evidence of ancient water flow carved by catastrophic flooding. The polar ice caps are composed of water ice and dry ice (frozen carbon dioxide). It exhibits seasonal changes due to sublimation and deposition cycles. There are multiple impact craters on the surface of Mars. Hellas Basin is one of the largest impact craters, with a diameter of 2,300 kilometers.
Mars’ atmosphere
The composition of the Martian atmosphere differs greatly from Earth’s. Earth’s atmosphere is 78% nitrogen, 21% oxygen, 1.0% argon, 0.04% carbon dioxide, and small amounts of other gases. Mars’s atmosphere is thin, with a surface pressure of about 6 millibars (0.6% of Earth’s). Its primary components are:
- Carbon Dioxide (CO₂): ~95.3%
- Nitrogen (N₂): ~2.7%
- Argon (Ar): ~1.6%
- Trace Gases: Oxygen, water vapor, and methane in minute quantities.
The layers of the atmosphere on Mars have been divided into four parts starting from its surface. Troposphere is the fisrt layer and it extends up to 10-20 kilometers. This is the layer where weather phenomena occur. Mesosphere is the next layer which is characterized by decreasing temperatures. Then there is Thermosphere that has high-energy particles which interact with each other and give rise to auroras. The last layer is Exosphere where atmospheric particles escape into space.
When talking about the overall temperature of mars, it has been found that Mars is a cold planet. On average, it has been estimated that mars temperature is around -80 degrees Fahrenheit. As already stated that, the pressure on atmospheric Mars is one sixth as compared to Earth, so it doesn’t remain heated for long and the temperatures drop down quickly. When there is winter on Mars, the temperature near the poles on Mars can get down to around -195 degrees Fahrenheit which estimates to around -125 degrees Celsius. However, a regular summer day on Mars can get up to a temperature of 70 degrees Fahrenheit estimating to about 20 degrees Celsius near the equator. Owing to an astonishing phenomenon, on summer nights the temperatures may drop off to around -100 degrees Fahrenheit estimating to around -73 degrees Celsius. As stated earlier, Mars is tilted along its axis so it has same type of seasons as we experience on Earth.
Dust storms are common on the Red Planet. These can be small tornadoes, called dust devils, or global storms that form when the Sun heats dust on the surface, causing it to rise up into the planet’s thin atmosphere. The researchers found that about 68% of large dust storms were preceded by a sharp increase in surface temperatures. These warm periods appeared to act as a trigger for storm formation, with a few weeks of heightened heat followed by the emergence of dusty conditions. Local dust storms often arise, especially at the edges of the polar carbon dioxide ice caps. Mars experiences significant temperature differences between the ice caps and the surrounding regions. During the spring and summer, when sunlight warms the polar ice caps, carbon dioxide sublimates (turns directly from solid to gas). This creates a strong temperature contrast between the icy regions and the adjacent warmer areas.
The sublimation of carbon dioxide increases local atmospheric pressure near the poles. This pressure difference drives winds, which can lead to the development of storms, especially dust storms, as these winds pick up and transport fine Martian dust particles. Also, Mars has a more elliptical orbit compared to Earth, leading to greater seasonal variations in sunlight and temperatures. These variations amplify the processes of sublimation and condensation, contributing to dynamic weather patterns near the ice caps. Like on Earth, Mars has atmospheric circulation patterns, including jet streams. Near the poles, these can create turbulent weather, including storm systems. Dust storms on Mars are often tied to interactions between dust and water vapor in the atmosphere. When water vapor near the ice caps interacts with rising dust, it can enhance storm activity by affecting the transfer of heat and energy in the atmosphere.
The soil on Mars
The soil on Mars, often referred to as regolith, is a mixture of fine dust, sand, and rocky debris. Its composition is distinct due to the planet’s geology and lack of biological activity. Silicates are the dominant component of Mars’ soil, primarily made of silicon and oxygen, similar to Earth’s crust. The common minerals include olivine and pyroxene, indicative of basaltic (volcanic) origin. Feldspar is a significant component in Martian basalts. The reddish appearance od Mars is due to Iron Oxides of which Hematite (Fe2O3) and magnetite (Fe3O4) are prevalent. Magnesium and aluminium oxides are present in smaller quantities. Sulfate salts such as calcium sulfate (gypsum) and magnesium sulfate are abundant in some regions, especially in areas where liquid water or brines once existed. Salts containing chlorine and oxygen were discovered by the Phoenix Mars Lander. These are significant because they can lower the freezing point of water and may impact potential habitability. Phosphorus, sodium, potassium, and other trace elements exist in small amounts, likely from volcanic activity. Trace amounts of simple organic compounds (like chlorinated hydrocarbons) have been detected, but these are not necessarily indicative of life. Martian regolith contains hydrated minerals and can adsorb water vapor from the atmosphere. It should be noted here that Martian soil contains toxic compounds like perchlorates, which pose a challenge for human colonization.
Moons of Mars
Mars has two small moons: Phobos and Deimos. These moons are thought to be captured asteroids or fragments of the early solar system. Phobos has been named after the Greek god of fear, son of Ares (Mars in Roman mythology). Its size is about 27 x 22 x 18 kilometers, making it the larger of the two moons. It orbits very close to Mars, orbiting at a distance of about 6,000 kilometers. It completes an orbit in just 7 hours and 39 minutes, faster than Mars’ rotation, causing it to appear to rise in the west and set in the east. It is gradually spiraling inward and is expected to crash into Mars or break apart in about 50 million years. It is heavily cratered, with the largest crater being Stickney Crater.
Deimos, the second moon of Mars has been named after the Greek god of terror, another son of Ares. It is smaller than Phobos, with dimensions of about 15 x 12 x 11 kilometers. It orbits Mars at a distance of about 23,500 kilometers. It takes about 30.3 hours to complete one orbit. It is slowly moving away from Mars over time. It is smoother appearance compared to Phobos, as craters are partially filled in with dust.
Evidence supporting the possibility of life on Mars
Ancient river valleys, lakebeds, and deltas observed by Mars rovers and orbiters suggest Mars had abundant liquid water billions of years ago. Clay and sedimentary rocks indicate long-standing water activity, a key ingredient for life. Recent findings suggest that liquid water brines may exist beneath the surface in polar regions. Subsurface environments could protect potential life from harsh surface conditions, such as radiation and extreme temperatures. Organic molecules, the building blocks of life, have been detected in Martian soil and rocks by missions like Curiosity and Perseverance. While these organics are not direct evidence of life, they provide the raw materials necessary for it. Most importantly, methane, a potential biosignature, has been intermittently detected in Mars’ atmosphere by orbiters and rovers. Methane could be produced biologically (by microbes) or abiotically (through geological processes). All these observations suggest that if adequate biological conditions are created on Mars, life can be possible on its surface.
Challenges for life on Mars
The most important challenge is that Mars lacks a strong magnetic field and a thick atmosphere, exposing its surface to intense cosmic and solar radiation. These radiations are capable of destroying various forms of life on its surface. Surface temperatures Mars averages around -60°C (-80°F) which create difficult condition for humans. Mars is extremely arid, with minimal liquid water on the surface. Furthermore, toxic perchlorate salts in Martian regolith could be harmful to life and complicate the existence of liquid water. The highly oxidizing conditions on the Martian surface break down organic molecules, making the survival of complex life forms difficult. At present life is possible on Mars only in strictly isolated conditions where all the above stated problems are nullified.
Making Mars inhabitable for humans
Making Mars inhabitable for humans would require substantial efforts to modify its environment to support life as we know it. This process is called terraforming and involves a combination of engineering, biological, and chemical solutions. As already stated, Mars’ atmosphere is over 95% carbon dioxide (CO₂), with very little oxygen and a surface pressure of about 0.6% that of Earth’s. Humans can not survive in this environment. So, artificial shielded habitats can be made which can fulfil the requirements. The lack of breathable oxygen and essential resources for human life is a major hurdle. This problem can be addressed by electrolysis of water (H₂O) to generate oxygen and hydrogen. Another technique is to introduce bioengineered oxygen-producing plants or microorganisms to thrive in Martian conditions. Mars has an average temperature of around -60°C (-80°F). Warming the planet using greenhouse gases or advanced technologies like orbital mirrors can be used to increase solar radiation. Mars lacks a magnetic field, so its surface is bombarded by harmful cosmic and solar radiation. This problem can be solved by building underground or shielded habitats or developing advanced radiation-blocking materials or potentially create artificial magnetic fields around colonies.
While Mars has frozen water in its polar caps and possibly underground aquifers, liquid water is rare. Using technology to extract, purify, and manage water resources, possibly melting ice or mining water from hydrated minerals. Introducing genetically modified organisms, such as algae and bacteria, to produce oxygen and enrich the soil will be one of the most important tasks for humans. Establishing large-scale greenhouses with controlled environments to grow plants and produce food shall be our first major step in creating a human colony on Mars. Using advanced robotics and AI to build infrastructure and perform terraforming tasks remotely will play a very important role in our Mars journey.
Mars represents humanity’s next great frontier. While the challenges of colonizing the red planet are immense, so too are the opportunities. Advancements in technology, coupled with international collaboration and ethical foresight, can make the dream of a Martian home a reality. As we look to the stars, Mars offers a beacon of hope and a chance to redefine our place in the universe. The journey will be arduous, but the rewards -scientific discovery, survival of our species, and a new chapter in human history- are worth the effort.
