An ideal scenario for the future would be to undertake several separate initiatives in the realm of planet-scale engineering to turn Mars from an inhospitable world unfit for human habitation into a place where life can flourish unchecked. The process is likely to include several resource-intensive activities to restore the planet's current climate, atmosphere, and surface, as well as the installation of a new ecological system or systems.
The abundance of water on Mars and its geological history, which implies it formerly had a dense atmosphere akin to Earth's, are good reasons for terraforming Mars rather than other possible destinations. Low gravity, low light levels compared to Earth, and the absence of a magnetic field are just some of the dangers and challenges you'll face.
Concerns regarding whether existing technology can make the planet habitable are open to debate. There are also ethical and financial considerations concerning terraforming, as well as the enormous cost of pursuing such an endeavor. Allaying worries about Earth's resource use and depletion and assertions that terraforming and later or concurrent settlement of other planets reduces the odds of humanity's extinction are among the reasons for terraforming the planet.
Humans may have to leave Earth to meet the needs of an increasing population, as well as a possible alternative to the Doomsday argument. It would be easier to collect the solar system's energy and material resources if humans were to colonize the solar system.
Mars is the most Earth-like planet found in the Solar System in many ways. For an extended period, it is considered that Mars had a thicker atmosphere and copious water, which was gradually drained away by atmospheric escape over many millions of years. Mars would be an ideal terrain target because of its similarities and proximity to Earth.
As an unintended consequence of terraforming, any native life, including microorganisms, that may be present may be dislodged or destroyed.
There is evidence that liquid water was present on the surface of Mars at some point in the past, and terraforming would bring it back to that state. Oxygen and nitrogen would be ejected into space at many times greater than today's.
These variables may limit how terraforming can take place on Mars, presenting numerous obstacles. Terraforming aims to address some of the differences between Mars and Earth:
- Reduced illumination (about 60 percent of Earth)
- Gravitation on the surface is low (about 38% of Earth's)
- An inhospitable setting
- Pressure in the atmosphere (less than 1% of Earth's; well below Armstrong's limit)
- Compared to the Earth's average temperature of 14 °C (287 K; 57 F), the average temperature of -63 °C (210 K; 81 F) is found.
- Breakdown of atomic bonding in organic compounds, for example, results in a state of molecular instability.
-Dirt storms around the world are becoming more common.
- There is no natural source of food.
- To protect against solar winds, there is no global magnetic field counteracting space weather's impacts.
There is no global magnetosphere on Mars, but the solar wind interacts with the atmosphere and creates a very small magnetosphere, which is not strong enough to prevent radiation from reaching its surface. As a result, solar radiation mitigation and preserving atmospheric conditions are challenging. Over time, it would have evaporated and lost its liquid water due to the lack of a magnetic field, as well as the atmospheric photochemistry. Martian atmospheric atoms have been expelled by the solar wind, which indicates that the solar wind has been eroding the Martian atmosphere over time. Contrast this with the lack of significant, dipole-induced magnetic fields on Venus, which has a highly dense atmosphere but only small amounts of moisture (about 20 ppm). The Earth's ozone layer provides additional protection. Water cannot be dissociated into hydrogen and oxygen because ultraviolet light is not available in high enough quantities.
There is 38 percent less gravity on Mars's surface than on Earth. Whether this is adequate to prevent weightlessness-related health issues is unknown.
One-tenth of the pressure of Earth's CO2 atmosphere at sea level is found at Mars's surface. The regolith and south polar cap contain enough CO2 ice to create an atmosphere with a pressure of 30 to 60 kilopascals [kPa] (4.4 to 8.7 psi) if released by global warming. It's possible that the return of liquid water to the Martian surface would increase the planet's temperature and density. However, due to Mars' weaker gravity, it takes 2.6 times Earth's column airmass to achieve the ideal surface pressure of 100 kPa (psi). There must be an external source for more volatiles to raise the atmosphere's density, like redirecting several giant asteroids (40-400 billion tonnes altogether) that contain ammonia (NH3) for nitrogen supply.
In the Martian atmosphere, where the pressure is less than one atmospheric pa (0.15 psi), body fluids such as saliva, tears, and the liquids that moisten the alveoli in the lungs boil away. This is far below the Armstrong limit of six atmospheric pa (0.87 psi). No amount of breathable oxygen, given in any way, can keep oxygen-breathing life alive for more than a few minutes without a pressurized suit. "My last conscious memory was of the water on my tongue beginning to boil," said one survivor in the NASA report Rapid (Explosive) Decompression Emergencies in Pressure-Suited Subjects. If not for a pressure suit, humans would perish in minutes in these conditions.
Unless the pressure on Mars can climb over 19 kPa (2.8 psi), then a pressure suit would not be necessary. An oxygen mask that supplied 100% oxygen under positive pressure would suffice for visitors. A simple mask delivering pure oxygen would be possible at a pressure of 24 kPa (3.5 psi). Hypoxia and mortality have been reported among mountain climbers who wander into the "death zone," or pressures below 37 kPa (5.4 psi). These climbers use a little amount of bottled oxygen to avoid the dangers of hypoxia. Nevertheless, if the rise in atmospheric pressure is made possible by increasing CO2 (or another harmful gas), the mask will have to ensure that the external atmosphere does not penetrate the respiration device. In humans, even 1% of CO2 is enough to make them sleepy. It can suffocate even in adequate oxygen concentrations of 7 to 10%.
But in 2021, NASA's Perseverance spacecraft succeeded in generating oxygen on Mars. To create even a trace amount of oxygen, the procedure is laborious and time-consuming.
Researchers believe that Mars is located on the outer border of the habitable zone, an area of the Solar System where liquid water may be sustained on the surface if concentrated greenhouse gasses can enhance the atmospheric pressure. Because of Mars' small size, the planet's interior may have cooled more rapidly than Earth's, resulting in a lack of magnetic field and geological activity. However, the specifics of this cooling process are still unknown.
During its early stages of evolution, Mars possessed an atmosphere that was as thick as Earth's and was capable of supporting plentiful liquid water on the surface. Ground ice can be found from the mid-latitudes to the poles on the surface of Mars, even though the water appears to have formerly been there. Sulfur, nitrogen, hydrogen, oxygen, phosphorus, and carbon are all present in the Martian soil and atmosphere.
As carbon dioxide (CO2) levels rise, more water vapor will be trapped in the atmosphere, causing climate change in the short term. This is the sole source of greenhouse warming anticipated in considerable proportions on Mars. Including the surface at the poles, where it is combined with dry ice, frozen CO2, water ice is abundant beneath the Martian surface. The south pole of Mars contains significant amounts of water, which, if melted, would create a 5–11-meter-deep ocean throughout the planet. Water residue is left behind by rapid winds that can reach 400 kilometers per hour when they sweep over the poles during the Martian summers, which melts the CO2 near the poles (250 mph). When this happens, vast volumes of dust and water freeze in the atmosphere, creating ice clouds resembling those seen on Earth.
Carbon dioxide (CO2), the primary atmospheric constituent, contains most oxygen in Mars' atmosphere. Only tiny amounts of molecular oxygen (O2) exist. Metal oxides on the Martian surface and soil contain large amounts of oxygen in the form of per-nitrates. Samples collected by the Phoenix lander showed that perchlorate, which is used in chemical oxygen generators, was present in the soil. If enough liquid water and electricity were available, electrolysis could be used to separate water on Mars into oxygen and hydrogen. As a result, if it were released into the atmosphere, it would be blown away.
Building up the magnetosphere, increasing the atmosphere, and boosting the temperature are all part of terraforming Mars. As a result of the thinness of Mars' atmosphere and the planet's extremely low surface pressure, the CO2 in Mars' atmosphere, a well-known greenhouse gas, may help keep the planet's surface warm once it begins to heat up. In addition, when it warms, more CO2 from the frozen reserves at the poles should reach the atmosphere, increasing the greenhouse effect. As a result, terraforming would be aided by the two processes of atmosphere construction and heating. However, the lack of a worldwide magnetic field to buffer the atmosphere from solar wind erosion would make it impossible to maintain the atmosphere intact.
Ammonia can be added to the Martian atmosphere to improve it (NH3). Minor planets in the outer Solar System are anticipated to have large amounts of ammonia frozen in their atmospheres. Redirecting the orbits of these and other, smaller ammonia-rich objects may allow them to strike Mars, allowing the ammonia to be captured by the planet's atmosphere. Ammonia, on the other hand, is not a stable compound in the Martian atmosphere. After a few hours, it decomposes into (diatomic) nitrogen and hydrogen. Even though ammonia is an effective greenhouse gas, it is not expected to impact global warming in the near future significantly. The same mechanisms that stripped Mars of much of its original atmosphere are expected to deplete the nitrogen gas eventually, but this is anticipated to have taken hundreds of millions of years. The removal of hydrogen would be significantly faster because of the smaller weight of the hydrogen. Since carbon dioxide has a density 2.5 times more than ammonia's and nitrogen gas, which Mars can barely hang on to, has a density 1.5 times greater, any imported ammonia that does not break down would be lost to space rapidly.
Importing methane (CH4) or other hydrocarbons abundant in Titan's atmosphere and the surface might also help produce a Martian atmosphere. The CH4 would be released into the atmosphere, increasing the greenhouse effect. While ammonia (NH3) is a comparatively heavy gas, methane (CH4) is relatively light. Introducing it would cause it to dissipate even faster than ammonia into space, making it less dense than ammonia. Even if a way could be developed to keep methane from escaping into space, it would only be able to remain in the Martian atmosphere for a short length of time. From 0.6 to 4 years, it has been estimated.
CFCs, PFCs, and other potent greenhouse gases have been proposed as a means of warming Mars in the short term and keeping the planet's temperature stable in the long run. It is hoped that these gases will be introduced since they have a greenhouse impact that is hundreds of times greater than CO2. Sulfur hexafluoride and perfluorocarbons are fluorine-based alternatives to chlorine-based because the latter depletes the ozone layer. Approximately 0.3 microbars of CFCs would have to be put into Mars' atmosphere to melt the south polar CO2 glaciers. About three times as much CFC was produced on Earth between 1972 and 1992, translating to 39 million metric tons (when CFC production was banned by an international treaty). As these chemicals are destroyed by photolysis, it would be necessary to produce more constantly to keep the temperature stable. A terraformed atmosphere with earth-like pressure and composition might support a 70-K greenhouse effect with an annual injection of 170 kilotons of ideal greenhouse molecules (CF3CF2CF3, CF3SCF2CF3, SF6, SF5CF3, SF4(CF3)2).
For most concepts, a significant industrial effort would be required to produce the gasses on Mars. Findings from mineralogical investigations of Mars, which suggest that fluorine is present in the Martian bulk composition at a mass level of 32 ppm, support mining fluorine-containing minerals for CFC and PFC raw material (as compared to 19.4 ppm for the Earth).
Alternatively, rockets loaded with compressed CFCs could be sent toward Mars in a collision trajectory. When the rockets hit the ground, their payloads would be released into the atmosphere. While Mars undergoes chemical transformations and warms up, a continual stream of these "CFC rockets" would be required.
When installed in space, mirrors composed of thin aluminized PET film could help boost Mars's solar output. Directing the Sun's rays toward the surface of Mars might raise the planet's temperature directly. It's possible to use the 125-kilometer-wide mirror's efficacy as a solar sail to orbit Mars in a stationary position near the planet's poles and sublimate carbon monoxide.
Additionally, ice sheets contribute to the warming of the greenhouse effect. 'However, there have been some issues discovered. There is a significant issue with the difficulties of launching big mirrors off the ground.
Reducing the Martian surface's albedo (the proportion of light reflected from a surface) would also improve heat absorption from incoming sunlight. Phobos and Deimos, which are among the darkest bodies in the Solar System, or dark extremophile microbial life forms, such as algae, lichens, archaea, and bacteria, might be used to disperse dark dust and darken the surface. The atmosphere would warm due to the increased absorption of sunlight by the ground. It's unlikely that Mars could be made any darker, given that it already has the second-highest absorption of solar radiation of any planet in our solar system. The Martian dust storms are a final problem with albedo lowering. Albedo is increased, but sunlight is also blocked from reaching the planet's surface for weeks at a time by these blankets. As a result of this, the planet's surface temperature drops for months at a time. Only when the dust settles that the albedo-reducing material is completely obscured from the Sun's vision.
A little amount of oxygen could be added to the atmosphere by algae or other green life, but not nearly enough to support human existence. When CO2 is converted to oxygen, it is primarily turned into carbs if the water is not present. In addition, because atmospheric oxygen is lost to space on Mars (in contrast to Earth, which has an oxygen cycle), this would be a long-term loss for the planet. This life must be nurtured in a closed system for these two reasons. The secure system's albedo would be reduced (assuming the growth has a lower albedo than the Martian soil), but the planet's albedo would be unaffected by this process.
As of April 26, 2012, scientists at the German Aerospace Center's Mars Simulation Laboratory (MSL) stated that lichen has survived and shown excellent results on the adaption capability of photosynthetic activity during a simulation period of 34 days under Martian circumstances (DLR).
The Mars Ecopoiesis Test Bed shows its translucent dome to allow for solar heat and photosynthesis, as well as the corkscrew system to gather and encapsulate Martian dirt together with oxygen-producing Earth organisms. About 7 centimeters in total length (2.8 in).
NIAC and Techshot Inc. have been working together since 2014 to construct sealed biodomes that would use Martian soil oxygen-producing cyanobacteria and algae colonies as a source of molecular oxygen (O2). They must first, however, carry out a small-scale Mars test to see if the technology works as intended. Mars Ecopoiesis Test Bed is the name of the proposal. An Indiana startup called Techshot employs Eugene Boland as its Chief Scientist. They plan to deploy a small container of extreme photosynthetic algae and cyanobacteria on a future rover trip to the planets. There, the rover would insert 7 cm (2.8 in) long canisters, corkscrew them in, and then release oxygen-producing bacteria into the sealed Martian soil, allowing them to develop. To make liquid water, the hardware would utilize Martian subsurface ice. A relay satellite orbiting Mars would receive data from the system about any oxygen released as a metabolic byproduct.
If this experiment succeeds on Mars, they plan to establish a series of biodomes to manufacture and harvest oxygen for a future human journey to Mars. NASA would save a lot of money and time if it were possible to produce oxygen on Mars, which would allow for extended human visits to the red planet. While this ecopoiesis process is not intended as a method for the terraforming of Mars's atmosphere, it will be an essential step in the transition from laboratory studies to in-situ planetary in situ research, which NASA says is "of greatest interest to planetary biology, ecopoiesis, and terraforming."
Some methanogens may be able to withstand the low pressure on Mars, according to research presented in June 2015 by the University of Arkansas. Four species of methanogens survived in Rebecca Mickol's laboratory under low-pressure circumstances similar to those observed on Mars' subterranean liquid aquifer. It was Methanothermobacter wolfeii, Methanosarcina barkeri, Methanobacterium formicicum, and Methanococcus maripaludis that she examined. On Mars, methanogens are non-photosynthetic, do not require oxygen or organic foods, and use hydrogen as their energy source and CO2 (carbon dioxide). Therefore they might thrive in underground conditions.
One of the most critical aspects of terraforming Mars is to ensure that the atmosphere is not lost in space. A planet-wide artificial magnetosphere, according to some experts, could be useful in fixing this problem. Two NIFS Japanese scientists claim that a system of chilled longitudinal superconducting rings, each carrying a substantial quantity of direct current, may be built with existing technology. Another claim made in the same research says the technology can be used to transport and store planetary energy while still having a minimal influence on the planet's economics (SMES).
Solar particles might be shielded by a magnetic dipole field between the Earth and the Sun, according to NASA scientist Jim Green, who presented his idea at a workshop on planetary science in late February 2017. An artificial magnetosphere would be created near the Mars Lagrange orbit L1 at roughly 320 R. "Earth similar," and sustaining 50 T at 1 Earth-radius would be necessary for the field. The paper's abstract states that a magnet with a strength of 1–2 teslas (10,000–20,000 gauss) may be used to accomplish this. The shield, if built, might help the planet recover its atmosphere. Within a few years, the planet will be able to maintain half the pressure of Earth's atmosphere. Carbon dioxide in the ice caps at both poles would begin to sublimate (convert from solid to gas) without solar winds, warming the equator. Oceans would form as ice caps melted. Volcanic outgassing, which partially offsets Earth's present atmospheric loss, will eventually replenish the atmosphere enough to melt the ice caps and fill one-seventh of Mars's past oceans, according to the researcher.
A magnetic field strong enough to shield a terraformed Mars could be generated by ionizing and accelerating particles from the moon in a plasma torus along Phobos' orbit.
According to Zubrin and McKay, the total energy needed to melt the south polar ice cap was estimated in 1993. An estimated 120 MW-years of electrical energy would be necessary to construct mirrors large enough to melt the ice caps utilizing orbiting mirrors. While it's the most successful approach, it's also the least feasible. To achieve this warmth, an order of 1,000 MW-years would be required by potent halocarbon greenhouse gases. Carbon dioxide would, however, only increase atmospheric pressure from 6 to 12 mbar, or roughly 1.2 percent of Earth's mean sea level pressure, with all this CO2 in the atmosphere. Even if 100 mbar of CO2 were released into the atmosphere today, the amount of heat it would cause would be less than 10 degrees Celsius. It is also expected to be quickly eliminated from the atmosphere, either by diffusion into the subsurface and adsorption or by re-condensing onto the polar caps once it has reached the atmosphere.
Surface or atmospheric temperatures at which liquid water can exist have not been established, and liquid water could exist at temperatures as low as 245 K (28 °C; 19 °F). A temperature increase of just 10 degrees Celsius is far less than previously considered necessary to produce liquid water.