Mars and Earth: similarities and differences

Mars and Earth are two terrestrial planets that attract the attention of scientists and ordinary people. Mars is the fourth planet from the Sun, Earth is the third. Both planets have a solid surface, atmosphere, and satellites. But how similar are they to each other? And is there a chance that life on Mars could exist like on Earth?

In this article, we will look at the similarities and differences between Mars and Earth, as well as try to answer the question of the possibility of colonizing Mars.

 

Similarities between Mars and Earth

Mars and Earth have several common characteristics that make them similar to each other.

 

Length of the day

Mars and Earth rotate around their axis in roughly the same time. A day on Mars is only 37 minutes longer than a day on Earth. This means that Mars has a sleep-wake rhythm similar to Earth's.

 

Axial tilt

Mars and Earth have almost the same axial tilt — about 25 degrees. This affects the change of seasons on both planets.

 

Seasonal change

Mars and Earth have four seasons: spring, summer, autumn, and winter. However, due to Mars' greater distance from the Sun, the seasons on Mars are longer than on Earth. For example, winter on Mars lasts about 6 months, and summer about 7 months.

 

Presence of water

Mars and Earth have water in different states of aggregation. On Earth, water is found in liquid, solid, and gaseous states. On Mars, water is mainly frozen in the form of ice. However, scientists have discovered traces of brine that can flow on the surface of Mars in warm weather.

 

Geological surface structure

Mars and Earth have a diverse geological surface structure, including mountains, valleys, craters, plateaus, plains, and deserts. Mars has the highest mountain in the solar system — Olympus, which is 2.5 times higher than Everest. Mars also has the largest canyon in the solar system — Valles Marineris, which is 4 times longer and 10 times deeper than the Grand Canyon.

 

Presence of geological activity

Mars and Earth have signs of geological activity such as volcanism, tectonics, and erosion. On Earth, geological activity continues to this day, while on Mars it died down billions of years ago. However, scientists believe that Mars may have dormant volcanoes that could awaken in the future.

 

Presence of ice caps

Mars and Earth have ice caps at the poles, consisting of water and carbon dioxide ice. The ice caps on Mars change their size depending on the season, increasing in winter and decreasing in summer.

 

Satellites

Mars and Earth have satellites that orbit them. Earth has one satellite — the Moon, and Mars has two satellites — Phobos and Deimos. Mars' satellites are smaller than the Moon and are closer to the planet than the Moon is to Earth. Phobos and Deimos resemble asteroids and may have been captured by Mars from the asteroid belt.

 

Differences between Mars and Earth

Mars and Earth have many differences that make them unique and distinctive.

 

Size, mass, and density

Mars is smaller and lighter than Earth. The diameter of Mars is about 6,800 km, and Earth is about 12,700 km. The mass of Mars is about 10.7% of Earth's mass.

Mars has a lower density than Earth. The density of Mars is about 3.93 g/cm³, and Earth's is about 5.51 g/cm³. This is due to the different compositions of the planets. Mars is mainly composed of silicates and iron, while Earth is composed of silicates, iron, and nickel.

 

Presence of a magnetic field

Mars does not have a global magnetic field, unlike Earth. Earth's magnetic field protects the planet from the solar wind and cosmic radiation, and also maintains the atmosphere and climate.

Mars only has local magnetic fields that cannot provide sufficient protection. Scientists believe that in the past Mars had a global magnetic field, but it disappeared due to the cooling and extinction of the planet's core.

 

Gravity

Mars has lower gravity than Earth. Mars' gravity is about 38% of Earth's gravity. This means that a person on Mars weighs 2.6 times less than on Earth. For example, if a person weighs 70 kg on Earth, he will weigh about 27 kg on Mars. Lower gravity also affects jump height, flight speed, and muscle strength.

 

Distance from the Sun

Mars is farther from the Sun than Earth. The average distance of Mars from the Sun is about 228 million km, and Earth is about 150 million km. This affects the temperature and illumination of the planets.

 

Length of the year

Mars has a longer year than Earth. Mars orbits the Sun in 687 Earth days, and Earth in 365 days. This is due to the greater distance of Mars from the Sun and its slower movement along its orbit.

 

Average surface temperature

Mars has a lower average surface temperature than Earth. The average surface temperature of Mars is about -60°C, and Earth's is about 15°C. This is due to the smaller amount of solar radiation reaching Mars and its thin atmosphere, which cannot retain heat.

The temperature on Mars also varies greatly depending on the time of day, latitude, and season. For example, at the equator of Mars, the temperature can rise to 20°C during the day and drop to -80°C at night.

 

Weather

Mars has harsher and more changeable weather than Earth. Mars often has dust storms that can cover the entire planet and last for months. Dust storms affect the temperature, atmospheric pressure, and illumination of Mars' surface.

Mars also has clouds, fog, frost, and snow, but they are made of carbon dioxide ice, not water. There is no rain, thunder, snowfall, or rainbows like on Earth.

 

Amount of liquid water

Mars has less available liquid water than Earth. On Earth, liquid water makes up about 71% of the planet's surface and is found in oceans, seas, rivers, lakes, glaciers, and underground sources.

On Mars, liquid water is found in very small quantities and only in the form of brine that can flow on the surface in warm weather. Scientists believe that in the past Mars had more liquid water that formed oceans, rivers, and lakes, but it evaporated or froze due to the loss of the magnetic field and atmosphere.

 

Atmospheric composition

Mars has a different atmospheric composition than Earth. The atmosphere of Mars is mainly composed of carbon dioxide (95%), as well as nitrogen (2.6%), argon (1.9%), and traces of oxygen, water vapor, and methane.

The atmosphere of Earth is mainly composed of nitrogen (78%), oxygen (21%), and traces of carbon dioxide, water vapor, and other gases.

The composition of the atmosphere determines the temperature, pressure, weather, and breathing ability on the planets.

 

Atmospheric pressure

Mars has lower atmospheric pressure than Earth. The atmospheric pressure of Mars is about 0.6% of Earth's atmospheric pressure. This means that the air on Mars is very thin and cannot support life.

On Mars, it is impossible to breathe without a special spacesuit and oxygen tank. On Earth, the atmospheric pressure is high enough to provide normal breathing and the water cycle.

 

Surface composition

Mars has a different surface composition than Earth. The surface of Mars is mainly composed of silicates, iron, and oxides, which give the planet its red color.

The surface of Earth is mainly composed of silicates, iron, nickel, and other elements that form various types of rocks. Earth also has more organic substances that are associated with life.

 

Possibility of life

Mars has fewer possibilities for life than Earth. Earth is the only planet in the solar system known to have life. Earth has a moderate climate, liquid water, oxygen, a magnetic field, and a biosphere that create favorable conditions for the development of various forms of life.

Mars is a planet where life could have existed in the past, but it is now considered dead or extremely limited. Mars has a harsh climate, little liquid water, almost no oxygen, no magnetic field, and no biosphere, which makes the planet uninhabitable.

Scientists are exploring Mars in search of traces of ancient or modern life, such as microorganisms, fossils, or biomarkers. So far, such traces have not been found, but this does not exclude the possibility of their existence.

Scientists are also developing plans for the colonization of Mars, which involves creating an artificial environment capable of supporting human and other organisms' life.

 

Mars and Earth are two terrestrial planets that have many similarities and differences.

The similarities between Mars and Earth include the length of the day, axial tilt, seasonal change, presence of water, geological surface structure, presence of geological activity, presence of ice caps, and satellites.

The differences between these neighboring planets include size, mass, and density, distance from the Sun, length of the year, average surface temperature, weather, amount of liquid water, presence of a magnetic field, gravity, atmospheric composition, atmospheric pressure, surface composition, and possibility of life.

Conclusions about the possibility of life on Mars are still ambiguous, but scientists continue to study this issue and develop plans for the colonization of Mars. Mars and Earth are two amazing planets that deserve attention and study.