The Red Planet: The Feasibility and Implications of Terraforming Mars
When scientists examine Mars' surface, they see features that is the work of flowing liquids: streams, river valleys and deltas. This suggests that the planet may have once had a vast ocean covering its northern hemisphere. Elsewhere, rainstorms appear to have soaked the landscape, carving into the terrain. Suggestive of being covered in a thick atmosphere, capable of sustaining liquid water at Martian temperatures and pressures. In terraforming Mars essay discussed whether we can make this planet habitable or not.
Why Mars?
Although Mars does not look habitable, it possesses all the elements that are needed for life to exist. There are incredible resemblances between the Martian atmosphere that exists today and the atmosphere that existed on Earth billions of years ago that makes inhabiting mars a lot more believable. When the Earth was first formed, no oxygen existed on our planet and it, just like Mars, looked desolate. The atmosphere was made completely of carbon dioxide and nitrogen. It was not until photosynthetic bacteria developed on Earth that enough oxygen was produced to allow for the development of life-forms. In spite of its smaller size, the planet's land area is also roughly equivalent to the surface area of Earth's continents, meaning that, at least in theory, Mars has the same amount of habitable real estate. Unfortunately, however, the planet is currently wrapped in a thin carbon dioxide atmosphere and cannot support earthly life-forms. Just like the early earth's air. Methane gas periodically appears in the atmosphere, and the dusty soil also contains compounds that would be toxic to life. Although water does exist on Mars, it is locked into the planet's icy polar caps and buried, perhaps and hopefully in abundance, beneath the Martian surface.
In contrast, Earth's atmosphere consists of 78.1 percent nitrogen, 20.9 percent oxygen, and 1 percent other gases. Because of this, any humans visiting Mars today would have to carry with them vast amounts of oxygen and nitrogen to survive. Though, the similarity to the early Earth and modern Mars' atmosphere has led various scientists to speculate the same process that turned the Earth's atmosphere from predominantly carbon dioxide into breathable air could be repeated on Mars. This would thicken the atmosphere, creating a greenhouse effect that would heat up the planet, eventually providing a suitable living environment for plants and animals.
We have considered other planets as candidates for terraforming, including Venus, Europa (one of Jupiter's moons), and Titan (one of Saturn's moons). Yet, Europa and Titan are just too far off from the sun. Like our planet, Europa is thought to have an iron core, a rocky mantle, and an ocean of salty water, however, Europa's ocean lies below a shell of ice 10 to 15 miles. Meanwhile Venus is too close, the planet's surface temperature is 465 degrees Celsius and while the surface rotates slowly, the winds blow at hurricane force, sending clouds completely around the planet every five days. Mars stands on its own as the one other planet in our solar system, that might be able to support life.
How Terraforming Might Work?
Terraforming Mars will be a huge task if we ever actually try it at all. The initial stages of terraforming Mars could take several decades or even centuries. No matter how we do it, it is not a fast process. Terraforming the entirety of Mars into an Earth-like habitat would have to be done over an exceptionally prolonged period, several millennia. In this section I will discuss methods of how we would transform Mars into a habitable planet, capable of sustaining life. The first terraforming method that has been proposed is large orbital mirrors that will reflect sunlight and heat the surface.
NASA is currently working on a solar sail propulsion system that would use large reflective mirrors to harness the sun's radiation to propel spacecraft through space. Solar sails are giant, flat sheets of very thin, reflective material 40 to 100 times thinner than a piece of writing paper supported by an arrangement of lightweight booms or masts. The sails reflect sunlight, which provide the force needed to push a spacecraft through space, without using any fuel. Another use for these giant mirrors would be to place them a two to three thousand miles from Mars and use the mirrors to reflect the sun's radiation, heating Mars' surface. Scientists have suggested building mylar mirrors that would require a radius of 100km. These mirrors would weigh about 200,000 tons, meaning they would be too large to launch from Earth with the systems of transport we currently use. However, the material needed can be found in space, granting the possibility of building the mirrors in space.
If a mirror of this size were directed at Mars, it would increase the surface temperature of a small area by a few degrees. The concept would be to concentrate the mirrors on the polar caps, which would melt the ice and release the carbon dioxide that are believed to be trapped inside the ice. Over a phase of several years, the upsurge in temperature would release greenhouse gases, such as chlorofluorocarbons (CFCs). Mimicking the process that happened to Earth.
A mathematical model of the Martian CO2 environment is used to generate an analysis exploring and refining the prospects for the use of positive feedbacks to accelerate planetary engineering efforts. The model assumes that enough CO2 is present in the Martian regolith and south pole to generate a 300-600 mb atmosphere; when released by heating via orbiting mirrors, the CO2's greenhouse effect will function as a positive feedback supporting further warming.
Another option for thickening the atmosphere of Mars, would be to set up solar-powered, greenhouse-gas producing factories. Humans have had a lot of experience with this over the last century, as we have unintentionally released tons of greenhouse gases into our own atmosphere, which most believe is raising the Earth's temperature. The same heating effect could be recreated on Mars by setting up hundreds of these factories. Their only objective would be pumping out CFCs, methane, carbon dioxide and other greenhouse gases into Mars' atmosphere.
These factories either be transported to Mars or made from naturally occurring materials already located there, which would take years to process. To transport these machines to Mars, they would have to be very lightweight, able to be carried by rockets (the current technology available, if we had access to skyhooks which I will discuss in a later chapter, this transport may become a lot easier). These greenhouse machines mimic the natural process of plant photosynthesis, inhaling carbon dioxide and releasing oxygen. It would take many years, but the Mars atmosphere would slowly be oxygenated to the point that Mars's colonists living there would need only a breathing-assistance apparatus instead of full pressure suits like those worn by astronauts.
Space scientist Christopher McKay and Robert Zubrin, author of 'The Case for Mars', have also proposed a more extreme method for green housing Mars. The theory of hurling huge, icy asteroids containing ammonia at the Mars would produce a vast amount of greenhouse gases and water. For this to be carried out, nuclear thermal rocket engines would have to be somehow attached to asteroids from the outer solar system. The rockets would move the asteroids at about 4 kilometres per second, for a period of about 10 years, before the rockets would shut off and allow the 10-billion-ton asteroids to glide, unpowered, toward Mars. The energy released upon impact would be roughly 130 million megawatts of power, this is enough energy to power Earth for a decade.
The energy of one of these impacts would raise the temperature of the planet by 3 degrees Celsius. The abrupt rise in temperature would melt around a trillion tons of water, which is enough water to form a lake, with a depth of one meter, that could cover an area larger than the state of Connecticut. Several of these missions over roughly a 50-year period would create a temperate climate like Earth, and enough water to cover 25 percent of the planet's surface. However, the bombardment by asteroids, each releasing energy equivalent to 70,000 one-megaton hydrogen bombs, would delay human settlement of the planet for centuries. Therefore, this method of terraforming is not as relevant or high priority as other methods, unless the cost is of much lesser expense we will wantneed a quicker inhabitation period
The most recent method that we have discovered is a cyanobacterium called chroococcidiopsis, it is the most desiccation-resistant cyanobacterium, the sole photosynthetic organism in extreme arid habitats. It is also existent in a wide range of other extreme environments, including Antarctic rocks, thermal springs, and hypersaline habitats, but it is unable to compete with more specialized organisms. Genetic evidence suggests that all its forms belong to a single species. It is remarkable tolerance of environmental extremes makes it a prime candidate for use as a forerunner photosynthetic microorganism for terraforming of Mars. The hypo-lithic microbial growth form (which lives under stones of a desert pavement) could be used as a model for development of technologies for large-scale Martian farming.
While it is possible for us to end up reaching Mars this century, it could take us much longer, closer to the region of centuries for the idea of terraforming the planet to be put in place. Governing bodies would need an incredibly good reason to spend billions on the idea of space expansion. The Earth took billions of years to become a planet where life can flourish. Transforming the Mars landscape into one that resembles Earth is not only a complicated process, but also expensive and would have to be well justified.
Science fiction writers have long featured terraforming, the process of creating an Earth-like or habitable environment on another planet, in their stories. Scientists themselves have proposed terraforming to enable the long-term colonization of Mars. A solution most common to both groups is to release carbon dioxide gas trapped in the Martian surface to thicken the atmosphere and act as a blanket to warm the planet.
However, Mars does not retain enough carbon dioxide that could practically be put back into the atmosphere to warm Mars, according to a new NASA-sponsored study. Transforming the inhospitable environment into a place that astronauts could explore without life support is not possible without technology well beyond today's capabilities. Therefore, developments in technologies or use of alternative methods (for example chroococcidiopsis) would have to be met.
Ethical Considerations for Terraforming Mars
Mars is one of the most explored bodies in our solar system, and it is the only planet where we have sent rovers to roam the alien landscape. Two NASA rovers and one lander are currently exploring the surface of Mars (and a Chinese lander is set to land later this year). An international fleet of eight orbiters are studying the Red Planet from above. As our investigations into Mars become deeper, it is hoped that we will determine if there is any life to be found. There could be organisms living there that we have not discovered yet, if this is the case, questions must be raised with the ethicality of transforming the planet just for us to take over and inhabit. There may be extremophiles dwelling under the surface. Or the possibility of something a bit larger, like worms or insects. Of course, if there were still any herds of land animals roaming the surface, we likely would have seen them by now, but that does not prove that the entire place is lifeless.
Conclusion
To avoid ethical issues, we would prefer to have the question of life on Mars answered. Either a discovery of life, or enough strong evidence to suggest otherwise, for example a large proportion of the planet to be mapped and explored. By the time we have decided to start inhabiting the planet, most of the planet will be mapped because of our rapid technological growth, which will hopefully save us the question of ethicality.
