Relationship between Earth and Mars. What is the diameter of Mars and how does it compare to the diameter of Earth? Diameter, mass and description of Mars

Mars, like other inner planets, is characterized by the presence of a hard rocky surface, a unique atmosphere, temperature conditions and other characteristics. What they are and how different they are from other planets in the solar system will be discussed below.

Characteristics of Mars as a planet - it is the fourth planet from the Sun and the closest planet to Earth in the Solar System. The brightest object in the starry sky after the Moon during the days of the great confrontation. It is included in the terrestrial group, as it has a number of features and general characteristics similar to other planets.

Physical characteristics of Mars

The Red Planet has unique physical characteristics that make it similar to the Earth and other terrestrial planets. The physical characteristics of Mars are as follows:

• The inclination of the axis to the perpendicular to the plane is 25 degrees, in connection with this the planet has daily rhythms similar to Earth (days on Mars last 37 minutes longer than on Earth).
• The planet Mars has unique conditions that are unfavorable for humans and life in general: the average temperature is 210 K (-63 degrees Celsius), sharp daily and seasonal temperature fluctuations.
• The area of ​​Mars is approximately equal to the area of ​​the solid surface of the Earth - 144 million km.
• Diameter - 6779 km, equal to half the diameter of our planet.
• The mass of the red planet is 6.4171⋅1023 kg, which is 9.3 times less than Earth’s.
• Density is 106 times less than the density of the Earth.
• The volume of the planet is 6.1 1010 km³, which is equal to 0.151 Earth.
• Gravitational attraction is inferior in strength to that of the earth, and the acceleration of free fall of bodies at the equator reaches 3.7 m/s2.
• Atmospheric pressure is 0.6 kPa (160 times less than on Earth), the indicators fluctuate throughout the day and vary throughout the year.

Brief orbital characteristics

The Red Planet also has a number of astrophysical features and characteristics, for example:

• Mars is the fourth planet farthest from its star and moves in an elliptical orbit.
• The length of a Martian day is 24 hours 39´35´´, referred to as sol.
• The stellar rotation period is 24.622 9 hours. The equatorial rotation speed is 868 km/h.
• The orbital period is 686.971 days.
• The synodic period is 2.135 Julian years (779.96 days).
• The entire journey takes 687 Earth days or 668.6 sols.

Astronomical characteristics of Mars

• The orbital center is noticeably shifted, the average distance of the planet from the Sun is about 228 million km.
• The minimum value is perihelion – 206.6 million km; 206,669,000 km (1,381,497 AU).
• Maximum distance - aphelion - 249.2 million km; 249,209,300 km (1,665,861 AU).
• The average orbital speed is 24.13 km/s.
• The apparent magnitude is minus 2.91 m.
• The angular size indicator is in the range of 13″ – 14″.
• The orbit is inclined by 1.85°.

Mars is at its brightest and most visible on days of opposition (or oppositions), when the Earth is in a position between the Sun and Mars. When the red planet passes near perihelion and enters into opposition, in this case the latter is called great. Confrontations occur every 26 months, and great confrontations occur every 15-17 years.

Characteristics of the planet's satellites

• Mars has two moons, Phobos and Deimos, discovered by Hall in the late 19th century.
• Both orbit very close to the planet and have very unusual shapes.
• Phobos reaches a diameter of 22 km, and Deimos - 12 km.
• Phobos moves from west to east, taking 11 hours to complete its trajectory.
• Deimos rises from the east, but due to its very slow movement and lag behind the planet's rotation speed, 2.7 days pass from rise to sunset.
• The same period of rotation around its axis and relative to the planet, which is why only one side of both satellites always faces it.

Comparative analysis of Mars and other terrestrial planets

Mars is a unique planet, more than others, developed and studied by man. However, like all terrestrial planets, it has much in common with Mercury, Venus and Earth.

The main distinctive features of Mars are:

• The red tint of its surface is due to the content of iron oxide and the brown-red mineral maghemite in the bark.
• Two satellites: their number exceeds the number of satellites of other terrestrial planets.
• The location of the highest mountain, Mons, and the largest canyon, Valles Marineris, in the solar system.
• The presence of a weak, unstable magnetic field.

Mars is also considered a planet with characteristics similar to Earth, but the differences are still clearly visible. If we compare Mars with Earth, the differences will be, first of all, the following:

• The saturation of the Earth's surface with water in liquid form, when, as on Mars, its existence is impossible.
• The difference in the gas composition of the atmospheres: 78% nitrogen and 21% oxygen of the Earth versus 96% carbon dioxide of the red planet.
• The difference in surface temperatures: the average on Earth is 14 degrees, optimal for living organisms, while the average for Mars is -63 degrees.

Mercury is a planet with extreme conditions, significantly different from Mars, because:

• Mercury, due to its proximity to the Sun, has virtually no atmosphere, and the temperature on the heated surface reaches 300 degrees. The maximum temperature of Mars is 35 degrees.
• Mercury, despite its small size, has an extremely high density, comparable to the density of the Earth and exceeding the density of Mars.
• The period of rotation of Mars around its axis is practically no different from that of Earth, but exceeds the period of Mercury by 58 times.

Venus is the second planet farthest from the Sun, different from the red planet:

• An atmosphere that consists mainly of carbon dioxide (which is similar to Mars), but is characterized by high density in contrast to the thin Martian atmosphere.
• Seasonal rhythms. There is no change of seasons on Venus, since the angle of inclination of the axis is close to zero. There are 4 different seasons on Mars.
• Direction of rotation. Venus rotates in the opposite direction from Mars, and a day on it exceeds a day on Mars by 117 times.

The story about Mars for children contains information about what the temperature is on Mars, about its satellites and features. You can supplement the message about Mars with interesting facts.

Brief message about Mars

Mars is the fourth planet from the Sun. Named after the god of war for its blood red color.

The surface of the planet contains a large amount of iron, which, when oxidized, gives a red color. Due to the fact that Mars is close to Earth, scientists have suggested that there may also be life on this planet. After all, on Mars, just like on Earth, there is a change of seasons.

The Martian year is 2 times longer than the Earth's - 687 days, and the day is only slightly longer than the Earth's - 24 hours 37 minutes. After research using an interplanetary station, assumptions about life on Mars were refuted.

Mars is almost 2 times smaller than Earth. The climate of Mars is that of a cold, dry, high-altitude desert with mountains, craters and volcanoes. Mars has two satellites - Phobos and Deimos, which are translated from Latin as “Fear” and “Horror”. Deimos is the smallest satellite of the planet in the solar system.

Message about planet Mars

The fifth planet from the Sun is called the “red planet”. The planet was named after the ancient Roman god of war - people associated its reddish surface with bloody battles. This color is created due to the reflection of sunlight from the surface of the planet, which is covered with metallic dust of silicon, iron and magnesium. Iron on Mars oxidizes (rusts) and takes on a reddish hue.

Mars is almost half the size of Earth - its equatorial radius is 3,396.9 kilometers (53.2% of Earth's). The surface area of ​​Mars is approximately equal to the land area on Earth.

On Mars, as on Earth, there is a change of seasons. Temperatures on Mars the most favorable of all the planets in the solar system, excluding Earth. During the day they reach an average of 30ºС, and at night they drop to – 80ºС. At the poles of Mars the temperature is lower, so they, like the poles of the Earth, are covered with ice and snow. Thus, on Mars there are two favorable conditions for the emergence of life: favorable temperature and water, but there is no main thing - air. The atmosphere of Mars consists mainly of carbon dioxide (95%), and it contains only about 0.1% of the oxygen necessary for life.

Water on Mars is concentrated mainly at the poles in the form of snow and ice. If all this ice is melted, the surface of Mars will be covered by a global ocean similar to the Earth’s, the depth of which will be several hundred meters. Some scientists even put forward versions that it is possible to artificially create favorable conditions for human life on Mars. To do this, you need to increase the temperature on the surface of the “red planet” and plant plants there that will convert carbon dioxide into oxygen. However, all these ideas are still far from reality. Mars has two natural satellites: Deimos and Phobos.

Mars is famous for the presence of numerous mountains - the highest in the entire solar system. Martian Mount Olympus is 21 km high!

The average distance from Mars to the Sun is 228 million kilometers, the period of revolution around the Sun is 687 Earth days. A day on Mars is slightly longer than on Earth.

We hope the information presented about Mars has helped you. And you can leave your report about Mars through the comment form.

Mars belongs to the terrestrial planets (4th in terms of distance from the Sun). The atmosphere is rarefied, and the topography is a complex of impact craters, volcanic mountains, deserts, valleys, and polar ice caps. The main color of the planet is red-orange due to iron oxide, which is why it is called the red planet. There are also other colors: golden, brown, greenish-brown. This variety of shades comes from the minerals present in the soil.

The soil density is lower than on Earth. It is equal to 3.933 g/cm³, and near the Earth this indicator correspond to 5.518 g/cm³. The size of Mars relative to Earth is not in favor of the former. The red planet's diameter is approximately half that of Earth, with a surface area slightly less than Earth's land area. In numbers it looks like this:

Equatorial radius: 3396.2 km (0.52 Earth);

Polar radius: 3376.2 km (0.51 Earth);

Average radius: 3389.5 km (0.53 Earth);

Surface area: 144,371,391 sq. km (0.25 Earth).

For comparison, the land area of ​​the blue planet Earth is 148,939,063 square meters. km. This is only 29.2% of the total area of ​​the Earth. The rest is occupied by seas and oceans.

You should also know that the volume of Mars is 15% of the volume of the blue planet, and its mass reaches 11% of the Earth’s. Accordingly, gravity is only 38% of Earth’s. In numbers, the mass of the red planet is: 6.423 × 10 23 kg, against the earth’s 5.974 × 10 24 kg.

The topography of Mars has many unique features. The red planet is home to the highest mountain in the solar system - Olympus Mons (27 km in height). And also the largest Mariner Canyon. There is nothing like this on any other planet in the solar system. However, on Pluto's moon Charon, the canyon is large.

The southern and right hemispheres are radically different in their topography. There is a hypothesis that almost the entire northern hemisphere is an impact crater. In terms of area, it occupies almost 40% of the planet's surface, and if it is indeed a crater, then it is the largest in the Solar System.

This hypothetical crater is called the North Pole Basin. Some experts believe that it was formed 4 billion years ago from the impact of a cosmic body with a diameter of 1900 km and a mass that was 2% of the mass of Mars. But at present this basin is not recognized as an impact crater.

The external dimensions of Mars are not very impressive. The Red Planet is noticeably inferior to Earth in all respects. In addition, it has a weak magnetic field, which is directly connected to the interior of the cosmic body. The semi-liquid core has a radius of about 1800 km. It consists of iron, nickel and 17% sulfur. It contains 2 times more light elements than the Earth. Around the core is the mantle. Volcanic and tectonic processes depend on it, but it is currently inactive.

The interior of the red planet is “packed” into the Martian crust. It is dominated by elements such as iron, potassium, magnesium, calcium, and aluminum. The average thickness of the crust is 50 km, and the maximum is 125 km. Thickness earth's crust on average is 40 km, so in this indicator Mars wins over the blue planet. But in general, it is a small cosmic body, which is the second most important neighbor of the Earth after the Moon.

Vladislav Ivanov

The orbit of Mars is elongated, so the distance to the Sun changes by 21 million km throughout the year. The distance to Earth is also not constant. During the Great Oppositions of the Planets, which occur once every 15-17 years, when the Sun, Earth and Mars line up, Mars approaches the Earth at a maximum of 50-60 million km. The last Great Confrontation took place in 2003. The maximum distance of Mars from the Earth reaches 400 million km.

A year on Mars is almost twice as long as on Earth - 687 Earth days. The axis is inclined to the orbit - 65 °, which leads to the change of seasons. The period of rotation around its axis is 24.62 hours, i.e., only 41 minutes longer than the period of rotation of the Earth. The inclination of the equator to the orbit is almost like that of the Earth. This means that the change of day and night and the change of seasons on Mars proceeds almost the same as on Earth.

According to calculations, the core of Mars has a mass of up to 9% of the mass of the planet. It consists of iron and its alloys and is in a liquid state. Mars has a thick crust 100 km thick. Between them is a silicate mantle enriched in iron. The red color of Mars is precisely explained by the fact that its soil is half composed of iron oxides. The planet seemed to have “rusted.”

The sky above Mars is dark purple, and bright stars are visible even during the day in calm, calm weather. The atmosphere has the following composition (Fig. 46): carbon dioxide - 95%, nitrogen - 2.5%, atomic hydrogen, argon - 1.6%, the rest is water vapor, oxygen. In winter, carbon dioxide freezes, turning into dry ice. There are rare clouds in the atmosphere; there is fog over the lowlands and at the bottom of craters during the cold season.

Rice. 46. ​​Composition of the atmosphere of Mars

The average atmospheric pressure at surface level is about 6.1 mbar. This is 15,000 times less than , and 160 times less than the surface of the Earth. In the deepest depressions the pressure reaches 12 mbar. The atmosphere of Mars is very thin. Mars is a cold planet. The lowest recorded temperature on Mars is -139°C. The planet is characterized by sharp temperature changes. The temperature amplitude can be 75-60 °C. Mars has climate zones similar to those on Earth. In the equatorial zone, at noon the temperature rises to +20-25 °C, and at night drops to -40 °C. In the temperate zone, the temperature in the morning is 50-80 °C.

It is believed that several billion years ago Mars had an atmosphere with a density of 1-3 bar. At this pressure, water should be in a liquid state, and carbon dioxide should evaporate, and a greenhouse effect could arise (as on Venus). However, Mars gradually lost its atmosphere due to its low mass. The greenhouse effect decreased, permafrost and polar ice caps appeared, which are still observed today.

The tallest volcano in the solar system, Olympus Mons, is located on Mars. Its height is 27,400 m, and the diameter of the base of the volcano reaches 600 km. This is an extinct volcano that most likely erupted lava about 1.5 billion years ago.

General characteristics of the planet Mars

Currently, not a single active volcano has been found on Mars. There are other giant volcanoes near Olympus: Mount Askrian, Mount Pavolina and Mount Arsia, whose height exceeds 20 km. The lava that flowed out of them, before solidifying, spread in all directions, so the volcanoes are shaped more like cakes than cones. There are also sand dunes, giant canyons and faults, as well as meteorite craters on Mars. The most ambitious canyon system is the Valles Marineris, 4 thousand km long. In the past, rivers may have flowed on Mars, which left the channels observed today.

In 1965, the American Mariner 4 probe transmitted the first images of Mars. Based on these, as well as photographs from Mariner 9, the Soviet probes Mars 4 and Mars 5, and the American Viking 1 and Viking 2, which operated in 1974, the first map of Mars. And in 1997, an American spacecraft delivered a robot to Mars - a six-wheeled cart 30 cm long and weighing 11 kg. The robot was on Mars from July 4 to September 27, 1997, studying this planet. Programs about his movements were broadcast on television and the Internet.

Mars has two satellites - Deimos and Phobos.

The assumption about the existence of two satellites on Mars was made in 1610 by a German mathematician, astronomer, physicist and astrologer Johannes Kepler (1571 — 1630), who discovered the laws of planetary motion.

However, the satellites of Mars were discovered only in 1877 by an American astrologer Asaph Hall (1829-1907).

> Comparison of Mars and Earth

Compare Mars and planet Earth. How they are different and similar: size, atmosphere, gravity, distance to the Sun, living conditions, characteristics in numbers with photos.

Previously, scientists thought that the Martian surface was dotted with a system of canals. Because of this, they began to believe that the planet looked like ours and was capable of hosting life. But as we studied it in detail, we realized that there are many differences between the objects.

Now the Red Planet is a frozen desert, but once upon a time this world was similar to ours. They converge in size, axial inclination, structure, composition and presence of water. But differences prevent us from quickly colonizing the planet. Let's see how Mars and planet Earth differ.

Comparison of size, mass, orbit of Earth and Mars

The average Earth radius is 6371 km, and the mass is 5.97 × 10 24 kg, which is why we are in 5th place in size and massiveness. The radius of Mars is 3396 km at its equator (0.53 Earth's), and its mass is 6.4185 x 10 23 kg (15% Earth's). In the top photo you can see how much smaller Mars is than Earth.

The Earth's volume is 1.08321 x 10 12 km 3, and the Martian volume is 1.6318 × 10¹¹ km³ (0.151 Earth's). The surface density of Mars is 3.711 m/s², which is 37.6% of Earth.

Their orbital paths are completely different. The average distance of the Earth from the Sun is 149,598,261 km, and fluctuations from 147,095,000 km to 151,930,000 km. The maximum distance of Mars is 249,200,000,000 km, and its proximity is 206,700,000,000 km. Moreover, its orbital period reaches 686.971 days.

But their sidereal turnover is almost the same. If we have 23 hours, 56 minutes and 4 seconds, then Mars has 24 hours and 40 minutes. The photo shows the level of axial tilt of Mars and Earth.

There is also a similarity in the axis tilt: Martian 25.19° versus terrestrial 23°. This means that seasonality can be expected from the Red Planet.

Structure and composition of Earth and Mars

Earth and Mars are representatives of the terrestrial planets, which means they have a similar structure. It is a metallic core with a mantle and crust. But the density of Earth (5.514 g/cm3) is higher than that of Mars (3.93 g/cm3), that is, Mars accommodates lighter elements. The figure below compares the structure of Mars and planet Earth.

The Martian core extends over 1795 +/-65 km and is composed of iron and nickel, as well as 16-17% sulfur. Both planets have a silicate mantle around their core and a solid surface crust. The earth's mantle extends over 2890 km and consists of silicate rocks with iron and magnesium, and the crust covers 40 km, where in addition to iron and magnesium there is granite.

The Martian mantle is only 1300-1800 km and is also represented by silicate rock. But it is partially viscous. Kora – 50-125 km. It turns out that with almost the same structure, they differ in the thickness of the layers.

Surface features of Earth and Mars

This is where the greatest contrast is noted. It’s not for nothing that we are called the blue planet, which is overflowing with water. But the Red Planet is a cold and deserted place. There is a lot of dirt and iron oxide, which is why the red color appears. Water is present in the form of ice in polar regions. Also a small amount remains below the surface.

There are similarities in the landscape. Both planets contain volcanoes, mountains, ridges, gorges, plateaus, canyons and plains. Mars also boasts the largest mountain in the solar system, Olympus Mons, and the deepest chasm, Valles Marineris.

Both planets suffered from asteroid and meteorite attacks. But on Mars, these traces are better preserved, and some are billions of years old. It's all about air pressure and the lack of precipitation, which destroy formations on our planet.

Martian canals and ravines through which water could flow in the past attract attention. It is believed that the reason for its creation could be water erosion. They extend 2000 km in length and 100 km in width.

Atmosphere and temperature of Earth and Mars

Here the planets are radically different. The Earth has a dense atmospheric layer divided into 5 spheres. Mars has a thin atmosphere, and the pressure is 0.4-0.87 kPa. The Earth's atmosphere is composed of nitrogen (78%) and oxygen (21%), while Mars' atmospheric composition is carbon dioxide (96%), argon (1.93%) and nitrogen (1.89%).

This also affected the difference in temperature readings. The Earth's average is 14°C, the maximum is 70.7°C, and the minimum drops to -89.2°C.

Due to the thinness of the atmospheric layer and its distance from the Sun, Mars is much cooler. The average drops to -46°C, the minimum reaches -143°C, and can warm up to 35°C. The Martian atmosphere also contains a huge amount of dust (the particle size is 1.5 micrometers), which is why the planet appears red.

Magnetic fields of Earth and Mars

The earth's dynamo is driven by the rotation of the core, which produces currents and a magnetic field. This process is extremely important, because it protects earthly life. Admire the magnetic fields of Mars and Earth in this NASA diagram.

The Earth's magnetosphere functions as a shield that prevents dangerous cosmic rays from breaking through to the surface. But for Mars it is weak and lacks integrity. It is believed that these are only remnants of the original magnetosphere, which is now dispersed over various areas of the planet. The greatest tension is closer to the south side.

Perhaps the magnetosphere disappeared due to an intense meteorite attack. Or it’s all about the cooling process, which led to the stopping of the dynamo 4.2 billion years ago. Then the solar wind took over, removing the remains along with the atmosphere and water.

Satellites of Earth and Mars

Planets have satellites. Our Moon is the only neighbor responsible for the tides. It has been with us for a long time and is imprinted in many cultures. It is not just one of the largest satellites in the system, but the most studied.

Two moons orbit Mars: Phobos and Deimos. They were found in 1877. Their names are given in honor of the sons of the god of war Ares: fear and horror. Phobos extends over 22 km and its remoteness ranges between 9234.42 km and 9517.58 km. One pass takes 7 hours. It is believed that in 10-50 million years the satellite will crash into the planet.

The diameter of Deimos is 12 km, and the orbital path is 23455.5 km - 23470.9 km. The bypass takes 1.26 days. There are also additional satellites whose diameter does not exceed 100 m. They can form a dust ring.

It is believed that Phobos and Deimos were previously asteroids attracted by gravity. This is hinted at by their composition and low albedo.

Conclusion about Earth and Mars

We looked at two planets. Let's compare their main parameters (Earth on the left, and Mars on the right):

• Average radius: 6,371 km / 3,396 km.
• Weight: 59.7 x 10 23 kg / 6.42 x 10 23 kg.
• Volume: 10.8 x 10 11 km 3 / 1.63 × 10¹¹ km³.
• Semi-axis: 0.983 – 1.015 a.u. / 1.3814 – 1.666 a.u.
• Pressure: 101.325 kPa / 0.4 - 0.87 kPa.
• Gravity: 9.8 m/s² / 3.711 m/s²
• Average temperature: 14°C / -46°C.
• Temperature variations: ±160°C / ±178°C.
• Axial tilt: 23° / 25.19°.
• Length of day: 24 hours /24 hours and 40 minutes.
• Year length: 365.25 days / 686.971 days.
• Water: plentiful/intermittent (in the form of ice).
• Polar ice caps: Yes/Yes.

We see that Mars is a small and desert planet compared to us. Its characteristics show that the colonialists will have to face a huge number of difficulties. And yet we are ready to take risks and go on a journey. Moreover, the distance from Earth to Mars is relatively small. Maybe one day we'll make it our second home.