1. Comparison of Mars and Earth Environmental Data

	Earth	Mars
Length of Day	24 hours	24 hours 37 minutes
Length of Year	365.25 Earth Day	687 Earth Day
Water Resources	Exists in three states: solid, liquid and gaseous	Exists mainly in the solid state
Gravity	1G(9.81m/s2)	0.38G(3.71m/s2)
Atmospheric Pressure	1atm	0.006atm
Major Atmospheric Components	N2 78.08%,O2 20.95%,Ar 0.93%,CO2 0.04%,H2O small amount,and small amounts of other gases	CO2 95%,N2 2.7%,Ar 1.6%,O2 0.15%,H2O 0.03%,and small amounts of other gases
Temperature	13.9? on average	-153?~20?(-63? common value)
Climate	Diverse and hard to predict.	Dry and dusty with dust storms.More repeatable and predictable.
Radiation	0.21 mSv per year	240-300 mSv per year
Magnetic Field	Direction: From the South Pole to the North Pole.Intensity: about 25 microtesla	Direction: No global magnetic field but many small ones.Intensity: about 1/1000 of Earth
Geologic Structure	Crust, mantle, core	Crust, mantle, core(the core is large, about half the diameter of Mars.)
Soil	Mineral particles, organic matter, moisture, air, other biomass.Neutral or slightly acidic.	Silicate minerals, iron oxides, sulfates, small amounts of organic matter.Alkaline.
Major Terrain	Diverse terrain such as mountains, plains, rivers, lakes, oceans, etc.	Mountains, deserts, polar ice sheets, plains, volcanoes

	Earth	Mars
Caliber	12,756 km	6,792 km
Circumference	40,075 km	21,339 km
Surface Area	5.10 x 108 km2	1.44 x 108 km2
Volume	1.08 x 1012 km3	1.63 x 1011 km3
Mass	5.97 x 1024 kg	6.42 x 1023 kg
Density	5,514 kg/m3	3,933 kg/m3
Orbital distance	9.40 x 108 km	1.43 x 109 km
Perihelion	1.47 x 108 km	2.07 x 108 km
Aphelion	1.52 x 108 km	2.49 x 108 km
Mean Orbital Velocity	107,218 km/h	86,677 km/h
Axial inclination	23.5°	25.2°
Satellite	1	2 (called Deimos and Phobos)
Age	4.55 billion years	4.65 billion years

Similarities

• Rotation Period

Mars rotates approximately every 24 hours and 37 minutes, which is very close to Earth’s 24-hour cycle. Hence, Mars also experiences day and night alternation, with a pattern similar to that of Earth, making it easier for humans to adapt to Martian time. Activities and work on Mars can be scheduled similarly to those on Earth.

Scientific research indicates that the human circadian rhythm is not exactly 24 hours, but slightly longer. Harvard Medical School, by monitoring the daily rhythms of hormones and body temperatures of 24 healthy young and older men and women over a month, concluded that our internal clocks operate on a cycle of about 24 hours and 11 minutes. Other experiments suggest a period of about 25 hours.^[1]

In the hypothalamus of the human brain, the suprachiasmatic nucleus, which is dense with neurons involved in appetite and emotions, continuously receives external information and sends adjustment signals to other organs’ smaller biological clocks, forcing them to adapt to Earth’s 24-hour day-night rhythm. “We continually stress the organism by resisting Earth time, so we are always in a state of tension,” says Lipatov. He believes that under such conditions, people age faster and have shorter lifespans. Perhaps the Martian day of 24 hours and 37 minutes is better suited to the human constitution, allowing for more relaxation and comfort.

• Seasonal Changes

Mars orbits the Sun from west to east at an axial tilt of 25.19 degrees, close to Earth’s axial tilt of 23.5 degrees, thus experiencing similar seasonal changes. This facilitates human adaptation to seasonal variations for controlling temperature and energy use in habitats and aids in the development of agriculture. Agricultural practices from Earth, particularly those involving seasonal crops, can be referenced and studied analogously on Mars.

• Geological Structure

Both Mars and Earth are composed of a crust, mantle, and core, from the outside in. Mars has an average crust thickness of 24-72 km, a mantle about half as thick as its crust, and a core diameter of 3600 km, approximately half of Mars’s diameter.

This helps us build more stable and durable structures on Mars. For example, the crust serves as the direct foundation of our buildings, and its thickness, composition, and strength influence architectural design. The mantle affects the stability of the crust, impacting site selection, design, and planning. The core indirectly influences the crust and mantle; movements of the core affect mantle convection, which in turn affects the propagation of seismic waves. We need to consider the impacts of these seismic activities and design structures that can withstand seismic shocks. The heat generated by the core is conducted through the mantle and crust, leading to geothermal activity. We need to consider the risks associated with geothermal activity, including ground subsidence, fissures, and the possibility of volcanic eruptions.

• Age

The similar ages of Earth and Mars suggest that Mars may have rock types and geological structures similar to those of Earth. This information about the age similarity between Earth and Mars provides valuable reference and guidance for Martian architecture, enhancing the safety and reliability of Martian buildings. When selecting appropriate building materials and designing structures, we can take into account the factor of age. Moreover, we can better predict long-term changes in the Martian environment, thus designing buildings that are more suited to Martian conditions. Additionally, by understanding the age of Mars, we can further assess the erosion levels and topographical features of the Martian surface, which are crucial for selecting construction sites and designing building shapes.

Differences

• Orbital Period

Since Mars is farther from the Sun, its orbital period is about twice that of Earth, at 687 days. Consequently, the lengths of the seasons are also twice those of Earth. Therefore, in architectural design, we need to consider how to design buildings to adapt to prolonged periods of high and low temperatures.

• Atmosphere

Mars’s atmosphere primarily consists of CO2 (95%), N2 (2.7%), Ar (1.6%), and trace amounts of O2 (0.15%) and H2O (0.03%), whereas Earth’s atmosphere is mainly N2 (78%), O2 (21%), and small amounts of Ar and other gases. The atmospheric density on Mars is only 1% of that on Earth, which is extremely thin and directly affects atmospheric pressure. The lower the atmospheric density, the lower the atmospheric pressure. The high CO2 content and low O2 content necessitate special designs for the air circulation systems and life support systems within buildings. The low atmospheric density requires consideration of the structure and materials of buildings; the lower atmospheric pressure necessitates consideration of the impacts of a low-pressure environment on buildings and equipment. Additionally, CO2 can be extracted to provide carbon and oxygen. Together with water and hydrogen from water, Mars has the components necessary for the chemical production of plastics, hydrogen fuel, and life-support liquids. Apart from carbon dioxide, there is also nitrogen on Mars, an essential atmospheric component for sustaining life.

• Temperature

Due to the thin Martian atmosphere, the atmospheric backradiation is weak, resulting in low average temperatures of -26°C, with polar winters reaching -143°C, and equatorial summers up to 35°C. The seasonal and temporal distribution is uneven, and the poor insulation results in significant temperature variations. For these extreme temperature fluctuations, we need to design an effective temperature control system, make flexible use of the existing environment, and consider how to protect buildings from the damage caused by thermal expansion, contraction, high heat, and cold.

• Water Resources

Studies indicate that Mars once had liquid water, but most of it now exists in the form of ice, making water resources scarce. Additionally, due to the weak magnetic field, it can only be found underground.

Recent measurements from rovers on Martian orbiting satellites indicate that there is a substantial amount of ice within and beneath Martian rocks. At certain times of the Martian year, liquid water is observed on the surface. The Korolev glacier, located in the northern lowlands near the Martian north pole and characterized by its wavy dune terrain, is known as “Olympia Undae”. The size of the impact craters is protected from external influences by the terrain and a layer of cold air. Martian surface water is absorbed into the rocks of this red planet and trapped within minerals and salts. In fact, researchers estimate that 99% of the water that once flowed on Mars is still there. In 2001, images from the Mars Odyssey’s gamma-ray spectrometer showed the distribution of water in Martian soil. At the 55th Lunar and Planetary Science Conference, astronomers reported the discovery of a massive extinct volcano near the Martian equator and initially speculated that there might be glacial remnants below. This new volcano was named “Noctis Mons.”

Water resources are crucial for human life and the construction process. Therefore, we need to consider their impact on site selection, design a water recycling system within the building, and think about how to optimize water usage during construction.

1. Gravity

The surface gravity on Mars is about 38% of that on Earth, which is 3.724 m/s². This means that while the mass of objects remains the same, their weight is lighter.

With significantly lower gravity than Earth, engineering considerations are necessary for designing building structures and construction methods, as well as the design of everyday items for human use. For example, a person who can jump 0.5 meters high on Earth could theoretically jump about 1.32 meters high on Mars.

1. Magnetic Field

The direction is also from the south pole to the north pole. Currently, the strength is only about one-thousandth of Earth’s magnetic field. Unlike Earth’s global dipole magnetic field, Mars is composed of multiple localized dipole magnetic fields that exist only in certain areas, not globally.

The absence of a global magnetic field on Mars makes the Martian surface more susceptible to solar radiation and cosmic rays. Therefore, Martian buildings need stronger radiation protection, such as using radiation-blocking materials, to protect inhabitants from radiation damage. Moreover, since some regions on Mars lack a magnetic field, the navigation systems on Mars might need to rely on technologies different from those on Earth. For example, autonomous vehicles on Mars might depend on visual recognition or other non-magnetic navigation technologies.

1.  Radiation

Mars is mainly exposed to solar radiation and cosmic rays. Due to the lack of a magnetic field and a thin atmosphere, the intensity of radiation is strong. Mars’ atmosphere lacks sufficient water and carbon dioxide to absorb infrared rays, lacks ozone to absorb ultraviolet rays, and lacks stable air molecules, water, and dust to scatter and reflect cosmic radiation.

Therefore, we need to consider factors such as location, materials, and structures when designing radiation-proof buildings or cities. Mars’ atmosphere offers limited protection against radiation, and long-term bases should integrate radiation shielding devices.

1. Soil

Martian soil is primarily composed of silicate minerals, iron oxides (such as hematite and magnetite), sulfates, and a small amount of organic matter. Due to the low oxygen content in the atmosphere, it is not conducive to the formation and preservation of organic matter, resulting in a scarcity of organic matter on Mars, poor soil fertility, reduced nutrient availability, and low biotic activity, which hinder plant growth. Additionally, the lack of sufficient carbon dioxide and water vapor to maintain a stable acidic environment results in alkaline soil. The image below shows soil collected by the Curiosity rover, analyzed using its Alpha Particle X-Ray Spectrometer (APXS).

Mars has abundant gravel, which can be used as a building material. Martian soil contains sulfur, which can be used as a binder for 3D-printed concrete. According to measurements by the “Viking” Space Reserve, silica is the most common substance on Mars. It is also the basic component of glass and can likely be used to produce ceramics and glass products, including fiberglass. It can be produced on Mars in roughly the same way as on Earth.

We need to consider the stability and load-bearing capacity of the soil, as well as its impact on building materials. And think about how to enhance its biotic activity, which can aid in agricultural development and human survival.

1. Terrain

The main features include valleys, deserts, mountains, polar ice caps, plains, volcanoes, and impact craters. There are differences between the north and south; the south is dominated by highlands full of impact craters, while the north primarily consists of younger plains.

• climate

The Martian climate is dry and dusty, with frequent dust storms. Wind speeds can reach up to 120 kilometers per hour, especially during the summer. Due to the flying dust, Mars becomes very murky, and the dust from sandstorms may take months to settle.

Therefore, during construction, we need to consider building structures and material shapes to enhance their resistance to wind and natural disasters.

• Satellites

Earth has one satellite—the Moon, while Mars has two satellites—Phobos and Deimos, differing in number. Additionally, Mars’ two satellites are relatively small, and their orbits are very close to Mars.

The difference in the number of satellites and their conditions may affect communication and navigation. Mars has more satellites, which may lead to more complex communication and navigation signals on Mars. This is because each satellite has its own orbit and communication equipment, which may cause signal interference or overlap. Additionally, the satellites are small and their orbits unstable, making the communication and navigation signals on Mars relatively unclear and inaccurate.

References

[1]William J. Cromie.(July 15, 1999). Human Biological Clock Set Back an Hour. The Harvard Gazette.

[2]”Gazetteer of Planetary Nomenclature | Korolev”. usgs.gov. International Astronomical Union. Retrieved March 4, 2015.

[3]https://en.wikipedia.org/wiki/Korolev_(Martian_crater)