Four billion years ago, Mars may have had an atmosphere rich with oxygen that provided conditions conducive to life despite losing much of its atmosphere to space.
Making Mars habitable doesn’t need to be an herculean undertaking – researchers say patches can be transformed quickly and affordably by layering thin silica aerogel sheets on its ground.
Temperature
Though Mars may appear hostile now, its surface was once much different. Billions of years ago it may have had thicker atmosphere with oceans of liquid water. Research shows some features consistent with such climate such as lack of ice at equator and valley networks created by running waterways.
Researchers used computer simulation to explore what Mars’ climate looked like at various points throughout its history. They discovered that during the Noachian period (4.1 billion to 3.6 billion years ago), atmospheric pressure was high enough for water to exist on its surface – lakes or rivers perhaps? Furthermore, temperatures may have supported methanogenic life forms that make their living by converting carbon dioxide and hydrogen into methane gas.
At some point in time, solar luminosity increased and Martian atmospheric conditions warmed, initiating greenhouse warming. This may have induced an increase in atmospheric pressure which allowed liquid water to form lakes in crater rims or perhaps an ocean within these craters.
Another potential scenario on Mars involves CO2 that has been absorbed in the regolith (the layer of material on top of Martian soil). If this were to occur, greenhouse effects similar to Earth may develop, though likely at a much slower pace given that Mars is much colder and drier.
Some scientists suggest it might be possible to recreate Mars’ atmosphere through artificial means by artificially increasing atmospheric pressure using rockets fueled with chemically inert CFC rockets aimed at its surface, in a similar manner as natural greenhouse gases but at much reduced costs and risk. Such CFC rockets would need to remain on orbit for around 10 years in order to substantially change both composition and temperature; this risky strategy also involves using large amounts of propellant.
Atmosphere
Mars currently has an atmosphere composed primarily of carbon dioxide. But historically it once boasted a dense layer of hydrogen and carbon atoms; though this atmosphere layer was lost billions of years ago. Scientists believe that previous versions could have supported life due to an active magnetic field protecting Earth’s atmosphere from harmful solar rays; something Mars no longer enjoys so atmospheric gases continue to leak into space without protection – making creating a habitable environment difficult.
Researchers are trying to create a thicker atmosphere on Mars by employing cyanobacteria – blue-green algae – as a source of oxygen production. Unfortunately, this method has proven ineffective; constant light must be provided in order for cyanobacteria to survive; even though sunlight is abundant on the planet itself, its absence does not allow enough light to meet this criteria. Furthermore, their byproducts are toxic for human colonists so another means must be found of producing oxygen on its own.
Aerogel could provide one potential solution. Researchers have discovered that just a thin layer of this water-resistant, breathable material can significantly increase average mid-latitude temperatures on Mars to Earth-like levels. Plus, aerogel makes for ideal habitat domes and biospheres on the red planet!
Scientists are developing advanced technologies for changing Mars’ atmosphere. For instance, NASA’s Perseverance Rover’s MOXIE experiment seeks to convert carbon dioxide from Martian air into oxygen that humans could breathe easily; such a solution would enable human explorers to avoid costly pressure suits in future expeditions.
One strategy involves building greenhouses on Mars’ surface and using solar radiation to heat them, raising both its surface and underground structures to an environment more suitable for human habitation. Advanced technological tools have already been created with this goal in mind, such as photo-dissociation technology that splits CO2 into carbon and oxygen using ultraviolet lasers; mathematical models show how breaking through its polar ice may lead to ocean formation, providing water supplies to meet planet’s water demands;
Water
Water is the main challenge to life on Mars. Though evidence points towards liquid water once existing on its surface environment, perchlorates are toxic to microorganisms that could support life there. In order to make Mars habitable again, scientists must locate underground reservoirs of liquid water that could be fed with enough breathable oxygen supply from above ground reservoirs – which research points towards.
Scientists have recently identified organic compounds found in rocks and sediments on Mars that may have served as precursors for prebiotic chemistry. Furthermore, using methanogenic microbes and geological processes from Mars as models for understanding past or present environments that supported life – and these same models can now help assess whether such organisms exist today on the red planet’s surface.
Scientists are considering alternative structures to traditional homes on Mars in order to support life there, such as ice igloos and underground habitats, designed to withstand radiation levels, temperature fluctuations and lack of oxygen. Growing food on Mars will present further difficulties; crops likely won’t grow like they do on Earth; instead food could be grown using nutrient-rich water fed with artificial lighting as opposed to simply growing in soil.
An alternative solution to making Mars habitable could involve creating an atmosphere similar to Earth’s. A study published in Nature Astronomy suggests that areas of Mars’ surface could become relatively cheaply and efficiently habitable by placing thin layers of silica aerogel above or on its surface, warming and melting water ice while simultaneously blocking harmful ultraviolet radiation. Researchers estimated that 2- to 3-centimeter thick layers would allow enough visible light for photosynthesis while blocking hazardous UV radiation, and could be placed over large expanses of Mar’s surface.
Thick atmospheres have the ability to retain more heat than thinner ones, which plays a large role in whether Mars ever became habitable. Early Mars likely featured thicker atmospheres than it does today and more carbon dioxide and hydrogen – two greenhouse gases which help trap plenty of warmth for an ideal living climate.
Soil
Mars soil is an intricate blend of minerals, organic material and air which varies in texture, consistency, color and chemical properties. As a dynamic and vital natural resource it fulfills many vital roles – feeding plants and animals while also regulating water flow, buffering pollutants and cycling nutrients back into the environment. It is produced through climate, topography and living organisms acting over time on parent materials resulting in its composition.
Today’s view of Mars may paint it as an inhospitable wasteland, but that wasn’t always the case. Scientists believe that early Mars had thick atmosphere and liquid water lakes or rivers on its surface at one time.
Scientists have recently determined that at some point on Mars, its climate changed from being wet to being dry. They believe this happened 3.6 billion years ago when an important greenhouse gas was lost from the atmosphere, leading to reduced conditions for liquid water on its surface and eventually making liquid water disappear altogether.
Most Mars experts agree that an abundance of greenhouse gases would have created conditions conducive to life on Mars, including keeping its climate warm enough for existence. They believe the atmosphere would have been rich in carbon dioxide and hydrogen atoms, providing ideal conditions for methanogens – bacteria which convert organic matter into methane and nitrogen gas; well-adapted to harsh environments such as hydrothermal vents on ocean floors.
Researchers used computer models to simulate conditions under which methanogenic life would have flourished on Mars, then compared these simulations with an analysis of its climate history. Their findings suggested that although methanogens would initially thrived, they quickly started an irreversible feedback loop that caused temperatures to drop precipitously causing glaciation on its surface which drove all life underground before eventually leading to their demise.
To test their theory, the team simulated various environmental factors on Mars such as climate, atmospheric composition and rock composition. Furthermore, they conducted research into extremeophiles – microbes capable of living outside Earth environments – which would thrive. Their results suggested methanogenic bacteria might survive on Mars while more complex microorganisms like lichens and fungi may find it difficult adapting.