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 there could be life on Mars, like on Earth?

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


Similarities between Mars and Earth

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


Length of day

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


Rotation axis tilt

Mars and Earth have almost the same tilt of their rotation axis – about 25 degrees. This affects the seasons on both planets.


Change of seasons (seasonality)

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


Availability of water

Mars and Earth have water in different states of aggregation. On Earth, water is found in liquid, solid and gaseous forms. On Mars, water is mostly frozen in the form of ice. However, scientists have discovered traces of a salty solution that can flow on the surface of Mars during the warm season.


Geological surface structure

Mars and Earth have varied surface geological structures, including mountains, valleys, craters, plateaus, plains and deserts. Mars has the highest mountain in the solar system, Olympus Mons, which is 2,5 times higher than Everest. Mars also has the largest depression 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, but on Mars it died out billions of years ago. However, scientists believe that there may be dormant volcanoes on Mars that may awaken in the future.


Presence of ice caps

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



Mars and Earth have moons that orbit around them. The Earth has one satellite – the Moon, and Mars has two satellites – Phobos and Deimos. The satellites of Mars are smaller in size than the Moon and are located closer to the planet than the Moon is to Earth. Phobos and Deimos are similar to asteroids and may be captured by Mars from the asteroid belt.

Mars and Earth: similarities and differences


Differences between Mars and Earth

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


Size, weight and density

Mars is smaller and lighter than Earth. The diameter of Mars is about 6800 km, and that of Earth is about 12700 km. The mass of Mars is about 10,7% of the mass of the Earth.

Mars has a lower density than Earth. The density of Mars is about 3,93 g/cm³, and that of Earth is about 5,51 g/cm³. This is due to the different composition of the planets. Mars is composed primarily of silicates and iron, while Earth is composed of silicates, iron, and nickel.


Presence of magnetic field

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

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



Mars has less gravity than Earth. Mars' gravity is about 38% of Earth's. This means that on Mars a person weighs 2,6 times less than on Earth. For example, if on Earth a person weighs 70 kg, then on Mars he will weigh about 27 kg. Less gravity also affects jump height, flight speed and muscle strength.


Distance from the Sun

Mars is further from the Sun than Earth. The average distance of Mars from the Sun is about 228 million km, and that of 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 travels around the Sun in 687 Earth days, and Earth in 365 days. This is due to the greater distance of Mars from the Sun and the lower speed of its orbital movement.

Orbit of Mars

Orbit of Mars and other planets of the inner solar system |


Average surface temperature

Mars has a lower average surface temperature than Earth. The average surface temperature of Mars is about -60 °C, and that of Earth is about 15 °C. This is due to less solar radiation reaching Mars and a thin atmosphere that cannot retain heat.

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



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

Mars also has clouds, fog, frost and snow, but they are made of carbon dioxide ice rather than water. There is no rain, thunderstorm, snowfall or rainbows like on Earth.


Liquid water quantity

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 springs.

On Mars, liquid water occurs in very small quantities and only in the form of a salty solution that can flow along the surface during the warm season. 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 its magnetic field and atmosphere.


Atmospheric composition

Mars has a different atmospheric composition than Earth. The atmosphere of Mars consists mainly of carbon dioxide (95%), as well as nitrogen (2,6%), argon (1,9%) and traces of oxygen, water vapor and methane.

The Earth's atmosphere consists mainly 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 breathability of planets.


Atmosphere pressure

Mars has lower atmospheric pressure than Earth. The atmospheric pressure of Mars is about 0,6% of the atmospheric pressure of Earth. This means that the air on Mars is very thin and cannot support life.

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


Surface composition

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

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


Possibility of life

Mars has less potential for life than Earth. Earth is the only planet in the solar system on which life is known. The Earth has a temperate climate, liquid water, oxygen, a magnetic field and a biosphere, which create favorable conditions for the development of diverse life forms.

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

Scientists are exploring Mars looking for traces of ancient or modern life, such as microorganisms, fossils or biomarkers. So far, no such traces have 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 life and other organisms.

Mars and Earth: similarities and differences


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, the tilt of the rotation axis, the change of seasons, the presence of water, the geological structure of the surface, the presence of geological activity, the presence of ice caps and satellites.

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

Conclusions about the possibility of the existence 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.