The diameter and mass of Mars. The most interesting facts about Mars. Major dust storms

The weight of Mars is about 6.4169 x 1023 kg, which is about 10 times less than the mass of the earth.

The planet Mars bears the name of the ancient Roman god of war Mars - according to legend, precisely because of its reddish-"bloody" color. In relation to the Sun, Mars is in fourth place - between the nearest neighbors Earth and Jupiter. The length of the "path" between Mars and the Sun is about 228 million kilometers. In terms of its dimensions, this red planet is number seven among the other planets. Today we will find out how much Mars weighs compared to the rest of the planets, as well as other Interesting Facts"from the life" of this celestial body.

A little about Mars

Mars has long been of great interest to world scientists, since its "temperament" is very similar to the earth. Indeed, the Martian surface is covered with a layer of loose rocks (regoliths), which contain a lot of iron, mineral dust and stones. The composition of the Earth's soil is almost the same, except that it contains much more organic matter.

The weight of Mars is 6.4169 x 1023 kg

According to research, in the past, Mars had rivers, lakes, and even entire oceans. However, over time, the water completely evaporated, and today the liquid on the Red Planet is stored only underground and on the polar "caps" - in the form of ice.

The atmosphere of Mars contains 95% carbon dioxide and is highly rarefied. In addition, the Martian "air" is filled with small dust particles, giving it a reddish tint. The Martian climate is characterized dust storms. There is a theory that these hazardous weather events result from the absorption of sunlight by fine dust particles. As a result, the atmosphere of Mars heats up and a global storm rises above the planet.

Mars and Earth comparative characteristics and parameters

Size. The diameter of the Red Planet is 6792 km (along the equator), which is two times less than the Earth's - this figure near the Earth is 12756 km. So, Earth is about 1.877539 times larger than Mars. If we compare the entire area of \u200b\u200bthe earth's land and the surface of Mars, then these figures will be almost equal to each other.
Weight. Mars has a relatively small mass, about 10 percent of the Earth's mass. For comparison: Mars weighs 6.4169 x 10 23 kg, and the weight of the Earth is 5.9722 x 10 24 kg. In addition, the force of gravity on the Martian surface is less than the earth's by about 38%. Therefore, all objects on Mars will weigh less than on Earth. For example, if a child on the "native" planet weighs 32 kg, then on Mars its weight will be only 12 kg.
Volume and Density. It is known that the average density of Mars is 3.94 g/cm 3 , and that of the Earth is approximately 5.52 g/cm 3 . As you can see, compared to the Earth, the density of the Red Planet is quite low. After all, this indicator directly depends on the mass, and the mass of Mars is only 10% of the earth. As for the volume of Mars, it is equal to only 15% of the earth's volume. If we imagine the Earth as a hollow ball, then to fill it we need six such small "balls" as Mars.
The length of the orbit and the speed of movement of the planets in orbit. The Earth's orbit is 939,120,000 km, and that of Mars is 1,432,461,000 km. The orbital speed of Mars is 107,218 km/h, and that of the Earth is 86,676 km/h. So the duration of one complete revolution of Mars is about 687 Earth days.
Seasons. It has been scientifically proven that a Martian day lasts 40 minutes longer than an Earth day. The number of seasons on the two planets is the same, since the axial tilts are almost the same (Earth has 23.5˚, Mars has 25˚). However, the year on Mars is about twice as long as on Earth, so the seasons are also longer.

The mass of Mars and other planets of the solar system - a comparative analysis

As can be seen from the table, in the solar system, Mars is a fairly small planet in mass, only Mercury is smaller than it.

Is there life on Mars?

This question worried many generations of earthlings. After all, Mars contains all the necessary components for the origin of life - chemical elements (carbon, hydrogen, oxygen, nitrogen), a source of energy and water.

In addition, back in 1996, scientists found evidence of life on Mars at the level of microorganisms, including various complex organic molecules, grains of the mineral magnetite and microscopic compounds resembling petrified microbes. Of course, the opinions of scientists on this issue differ, but so far no evidence has been found of the complete absence of life on Mars.

So, now we know how much Mars weighs, its comparative characteristics with the rest of the celestial "inhabitants" solar system and other interesting facts.

Mars is the first planet in the solar system after the Earth, in which people have begun to show special interest for some time, caused by the hope that developed extraterrestrial life exists there.

The planet is named Mars in honor of the ancient Roman god of war (the same as Ares in ancient Greek mythology) forits blood-red color, due to the presence of iron oxide in the soil of Mars.

Main characteristics

Mars is the fourth largest planet from the Sun and the seventh largest planet in the solar system.It can be seen from Earth with the naked eye. It is second in brightness only to Venus, the Moon and the Sun.

Mars is almost half the size of Earth - its equatorial radius is3,396.9 kilometers (53.2% of the earth). The surface area of Mars is roughly equal to the land area of Earth.

The average distance from Mars to the Sun is 228 million kilometers, the period of revolution around the Sun is 687 Earth days.

The minimum distance from Mars to Earth is 55.75 million kilometers, the maximum is about 401 million kilometers.

Mars is closest to Earth during opposition, when the planet is in the opposite direction from the Sun.The distances between the Earth and Mars at the moments of confrontation vary from 55 to 102 million kilometers. A great opposition is called when the distance between two planets becomes less than 60 million kilometers. The great opposition of Earth and Mars is repeated every 15-17 years (the last was in August 2003).And ordinary - every 26 months in different points orbits of Mars and Earth.

Mars has a rotation period and seasons similar to Earth's, but its climate is much colder and drier than Earth's.

The planet's rotation period is 24 hours 37 minutes 22.7 seconds.

On Mars, as on Earth, there are two poles, North and South. Mars rotates fast enough that it has a slightly flattened shape at both poles. At the same time, the polar radius of the planet is about 21 kilometers less than the equatorial one.

The Martian year consists of 668.6 Martian solar days, called sols.

The mass of the planet Mars is 6.418 × 1023 kilograms (11% of the mass of the Earth).

Mars has two natural satellites, Phobos and Deimos, and three artificial satellites.

As of February 2009, there are three operational spacecraft orbiting Mars: Mars Odyssey, Mars Express and Mars Reconnaissance Orbiter, more than any other planet except Earth.

There are several inactive landers and rovers on the surface of Mars that have completed their missions.

Climate of Mars

The climate on Mars, like on Earth, is seasonal. The change of seasons on Mars occurs in much the same way as on Earth, but the climate there is colder and drier than ours. In the cold season, even outside the polar caps, light frost can form on the surface. A picture of frost was once taken by the Viking 2 aircraft..

Mars rover "Phoenix" at some point succeededto fix falling snow on Mars during"Martian winter". Snowfall on Mars was recorded using a laser, which is equipped with a rover. The rover managed to fix the snow with the help of a special laser with which it was equipped. Snow fell from a height of about 4000 meters, but it did not reach the surface of the planet, dissolving in the air.

The change of seasons on Mars is provided bytilt of its axis of rotation. In this case, the elongation of the orbit leads to large differences in the duration of the seasons. Unlike earthly ones, which have the same duration of 3 months. Mars has northern spring and summer, which fall on the part of the orbit that is farthest from the Sun. These seasons together last 371 sols, that is, noticeably more than half of the Martian year. Therefore, on Mars, northern summers are long and cool, while southern summers are short and hot.

Mars is characterized by a sharp temperature drop. Temperatures at the planet's equator range from +30°C at noon to -80°C at midnight. Near the poles, the temperature sometimes drops to −143°C, at which temperature carbon dioxide condenses. Mars is a very cold world, but the climate there is not much harsher than in Antarctica.

Not currently on Mars liquid water. However, most likely, the white polar caps, discovered in 1704, consist of water ice mixed with solid carbon dioxide. In winter, they extend a third (the south polar cap - half) of the distance to the equator. In the spring, this ice partially melts, and a wave of darkening spreads from the poles to the equator, which was previously mistaken for Martian plants.

The appearance of Mars varies greatly depending on the time of year. First of all, changes in the polar caps are striking. They grow and shrink, creating seasonal phenomena in the atmosphere and on the surface of Mars.The polar caps consist of two components: seasonal - carbon dioxide and secular - water ice. The thickness of the caps can range from 1 meter to 3.7 kilometers.

Previously, many researchers seriously believed that there is still water in a liquid state on the surface of Mars. This opinion was based on observations of periodic changes in light and dark areas, especially in polar latitudes, which were similar to continents and seas.

Dark grooves on the surface of Mars have been explained by some observers as channels for liquid water.

Later it was proved that these furrows did not actually exist, but were just an optical illusion.

Research conducted by the Mariner 4 spacecraft in 1965 showed that there is currently no liquid water on Mars.

Due to the low pressure, water cannot exist in a liquid state on the surface of Mars. With such a small pressure that is currently acting on the planet, it boils at very low temperatures, but it is likely that conditions were different in the past, and therefore the presence of primitive life on the planet cannot be ruled out.

On July 31, 2008, water in the state of ice was discovered on Mars at the landing site of NASA's Phoenix spacecraft. The device found ice deposits directly in the ground.

Data from NASA's Spirit and Opportunity rovers also provide evidence for the presence of water in the past (minerals found that could only form as a result of prolonged exposure to water).

The glacier hundreds of meters thick covers an area of thousands of square kilometers, and its further study can provide information about the history of the Martian climate.

According to modern concepts, the total volume of ice enclosed in the polar cap of the northern hemisphere is approximately 1.5 million kilometers, therefore, in the melted form, this ice could not form a giant ocean, which, according to many researchers, once covered almost the entire northern hemisphere. hemisphere of Mars. Thus, it remains a mystery where the water that once abounded on the now arid planet has gone.

Presumablyin the past, the climate of Mars may have been warmer and wetter, and liquid water was present on the surface, and it even rained.

Magnetic field and atmosphere of Mars

Mars has a magnetic field, but it is weak and extremely unstable. In different parts of the planet, it can differ from 1.5 to 2 times. At the same time, the magnetic poles of the planet do not coincide with the physical ones. This suggests that the iron core of Mars is more or less motionless relative to its crust, that is, the mechanism responsible for the Earth's magnetic field does not work on Mars.

Modern models of the internal structure of Mars suggest that Mars consists of a crust with an average thickness of 50 kilometers (and a maximum thickness of up to 130 kilometers), a silicate mantle (mantle enriched in iron) with a thickness of 1800 kilometers and a core with a radius of 1480 kilometers.

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, while the core is in a liquid state.

Because the magnetic field of Mars is so weak, the solar wind freely penetrates its atmosphere. Because of this, many reactions under the influence of solar radiation on Mars occur almost at its very surface.On Earth, a strong magnetic field does not transmit solar radiation, so all these reactions occur in the ionosphere and above.

The Martian ionosphere extends over the surface of the planet from 110 to 130 kilometers.

The atmosphere of Mars is 95% carbon dioxide. The atmosphere also contains 2.5-2.7% nitrogen, 1.5-2% argon, 0.13% oxygen, 0.1% water vapor, 0.07% carbon monoxide.

In addition, the atmosphere of Mars is very rarefied. The pressure at the surface of Mars is 160 times less than the Earth's at the average surface level. Due to the large elevation difference on Mars, the surface pressure varies greatly.

Unlike Earth, the mass of the Martian atmosphere varies greatly during the year due to the melting and freezing of the polar caps containing carbon dioxide.

There is evidence that the atmosphere may have been denser in the past.

Topography of Mars

Studies have shown that two-thirds of the surface of Mars is occupied by light areas, called continents, and the remaining third is dark areas, called seas. The nature of the dark areas is still a matter of controversy.But in fact, no water has been found in the Martian seas.

The seas are concentrated mainly in the southern hemisphere of the planet. There are only two large seas in the northern hemisphere - the Acidalian and the Great Syrt.

Large-scale images show that the dark areas are actually made up of groups of dark streaks and patches associated with craters, hills, and other obstructions in the path of the winds. Seasonal and long-term changes in their size and shape are apparently associated with a change in the ratio of surface areas covered with light and dark matter.

The hemispheres of Mars are quite different in the nature of the surface. The surface of Mars has a reddish color due to large impurities of iron oxides.

Everywhere on the surface of Mars lie boulders - pieces of volcanic rocks that have broken off during marsquakes or meteorite falls.

From time to time come across craters - the remains of meteorite impacts.

In some places, the surface is covered with multi-layered rocks, similar to terrestrial sedimentary rocks left after the retreat of the sea.

In the southern hemisphere, the surface is 1-2 kilometers above the mean level and is densely dotted with craters. This part of Mars resembles the lunar continents.

A large number of craters in the southern hemisphere may indicate that the surface here is ancient - 3-4 billion years.

The rovers exploring the planet left their marks on the untouched surface.

In the north, the surface is mostly below average, with few craters and mostly relatively smooth plains, probably formed by lava flooding and soil erosion.

In the northern hemisphere there are two areas of large volcanoes - Tarsis and Elysium.

Tharsis is a vast volcanic plain 2000 kilometers long, reaching a height of 10 kilometers above the average level. It has three large volcanoes.

On the edge of Tarsis is the highest mountain on Mars and on the planets in the solar system - the Martian extinct volcano Olympus.

Olympus reaches 27 kilometers in height and 550 kilometers in diameter. The cliffs that surround the volcano, in some places reach a height of 7 kilometers.

Currently, all Martian volcanoes are not active. Traces of volcanic ash found on the slopes of other mountains suggest that Mars was once volcanically active.

A typical landscape of Mars is the Martian desert.

Sand dunes, giant canyons and fissures have been photographed on Mars, as well as meteorite craters. The most grandiose canyon system - the Mariner Valley - stretches for almost 4,500 kilometers (a quarter of the planet's circumference), reaching a width of 600 kilometers in width and 7-10 kilometers in depth.

Soil of Mars

The composition of the surface layer of the Martian soil, according to the data of the landers, is different in different places.

The soil mainly consists of silica (20-25%), containing an admixture of iron oxide hydrates (up to 15%), giving the soil a reddish color. The soil contains significant impurities of sulfur, calcium, aluminum, magnesium, and sodium compounds. The ratio of acidity and some other parameters of Martian soils are close to those of the Earth, and it would theoretically be possible to grow plants on them.

From reports by lead research chemist Sam Kunaves:

“In fact, we found that the soil on Mars meets the requirements, and also contains the necessary elements for the emergence and maintenance of life, both in the past, in the present, and in the future ... .. Such soil is quite suitable for growing various plants, such as asparagus. There is nothing here to make life impossible. On the contrary, with each new study, we find additional evidence in favor of the possibility of its existence.”

Interesting phenomena on Mars

The Mars Odyssey spacecraft has detected active geysers at the south polar cap of Mars. Jets of carbon dioxide with spring warming break up to a great height, carrying dust and sand with them. The spring melting of the polar caps leads to a sharp increase in atmospheric pressure and the movement of large masses of gas to the opposite hemisphere.

The speed of the winds blowing at the same time is 10-40 m/s, sometimes up to 100 m/s. The wind lifts from the surface a large number of dust, leading to dust storms. Strong dust storms almost completely hide the surface of the planet. Dust storms have a noticeable effect on the temperature distribution in the Martian atmosphere.

After the landings of automatic vehicles on the surface of Mars, it became possible to conduct astronomical observations directly from the surface of the planet.

The picture of the night sky of Mars (and astronomical phenomena observed from the planet) differs from the earth's and in many ways seems unusual and interesting.

For example, at noon the sky of Mars is yellow-orange. The reason for such differences from the color scheme of the earth's sky is the properties of the thin, rarefied atmosphere of Mars containing suspended dust.

Presumably, the yellow-orange coloration of the sky is caused by the presence of 1% magnetite in dust particles constantly suspended in the Martian atmosphere and raised by seasonal dust storms. Duration of storms can reach 50-100 days.

Evening dawn on Mars turns the sky a fiery red or deep orange.

Mars is the fourth farthest from the Sun and the seventh largest planet in the solar system, named after Mars, the ancient Roman god of war, corresponding to the ancient Greek Ares. Mars is sometimes referred to as the "red planet" because of the reddish hue of the surface given to it by iron oxide.

Mars is a planet terrestrial group with a rarefied atmosphere. The features of the surface relief of Mars can be considered impact craters like those of the moon, as well as volcanoes, valleys, deserts and polar ice caps like those of the earth.

Mars has two natural satellites, Phobos and Deimos (translated from ancient Greek - "fear" and "horror" - the names of the two sons of Ares, who accompanied him in battle), which are relatively small and have an irregular shape. They may be asteroids captured by the gravitational field of Mars, similar to the asteroid (5261) Eureka from the Trojan group.

The relief of Mars has many unique features. The Martian extinct volcano Mount Olympus is the highest mountain in the solar system, and the Mariner Valley is the largest canyon. In addition, in June 2008, three papers published in the journal Nature presented evidence for the existence of the largest known impact crater in the solar system in the northern hemisphere of Mars. It is 10,600 km long and 8,500 km wide, about four times larger than the largest impact crater previously discovered on Mars, near its south pole. In addition to similar surface topography, Mars has a rotation period and seasons similar to Earth's, but its climate is much colder and drier than Earth's.

Until the first flyby of Mars by the Mariner 4 spacecraft in 1965, many researchers believed that there was liquid water on its surface. This opinion was based on observations of periodic changes in light and dark areas, especially in polar latitudes, which were similar to continents and seas. Dark furrows on the surface of Mars have been interpreted by some observers as irrigation channels for liquid water. It was later proven that these furrows were an optical illusion.

Due to low pressure, water cannot exist in a liquid state on the surface of Mars, but it is likely that conditions were different in the past, and therefore the presence of primitive life on the planet cannot be ruled out. On July 31, 2008, water in the state of ice was discovered on Mars by NASA's Phoenix spacecraft.

In February 2009, the orbital research constellation in the orbit of Mars had three functioning spacecraft: Mars Odyssey, Mars Express and Mars Reconnaissance Satellite, more than around any other planet except Earth. The surface of Mars currently explored two rovers: "Spirit" and "Opportunity". There are also several inactive landers and rovers on the surface of Mars that have completed research. The geological data they collected suggests that most of the surface of Mars was previously covered with water. Observations over the past decade have made it possible to detect weak geyser activity in some places on the surface of Mars. According to observations from NASA's Mars Global Surveyor, parts of the south polar cap of Mars are gradually receding.

Mars can be seen from Earth with the naked eye. Its apparent stellar magnitude reaches −2.91m (at the closest approach to the Earth), yielding in brightness only to Jupiter (and even then not always during the great confrontation) and Venus (but only in the morning or evening). As a rule, during the great opposition, orange Mars is the brightest object in the earth's night sky, but this happens only once every 15-17 years for one to two weeks.

In size, Mars is almost half the size of the Earth - its equatorial radius is 3396.9 km (53.2% of the Earth's). The surface area of Mars is approximately equal to the land area on Earth. The polar radius of Mars is about 20 km less than the equatorial one, although the planet's rotation period is longer than that of the Earth, which suggests a change in the rotation rate of Mars over time. The mass of the planet is 6.418 × 1023 kg (11% of the mass of the Earth). Acceleration free fall at the equator it is equal to 3.711 m / s² (0.378 earth); first space velocity is 3.6 km/s and the second is 5.027 km/s. Mars rotates around its axis, which is inclined to the perpendicular plane of the orbit at an angle of 24°56'. The planet's rotation period is 24 hours 37 minutes 22.7 seconds. Thus, a Martian year consists of 668.6 Martian solar days (called sols). The tilt of the axis of rotation of Mars causes the change of seasons. In this case, the elongation of the orbit leads to large differences in their duration. Thus, the northern spring and summer, taken together, last 371 sols, that is, noticeably more than half of the Martian year. At the same time, they fall on the part of Mars' orbit that is farthest from the Sun. Therefore, on Mars, northern summers are long and cool, while southern summers are short and hot.

The temperature on the planet ranges from -153°C at the pole in winter to over +20°C at the equator at noon. The average temperature is -50 °C.

Atmosphere of Mars.

The atmosphere of Mars, which consists mainly of carbon dioxide, is very rarefied. The pressure at the surface of Mars is 160 times less than the earth's - 6.1 mbar at the average surface level. Due to the large elevation difference on Mars, the pressure near the surface varies greatly. The maximum value reaches 10–12 mbar in the Hellas basin at a depth of 8 km. Unlike the Earth, the mass of the Martian atmosphere varies greatly during the year due to the melting and freezing of the polar caps containing carbon dioxide.

The atmosphere is 95% carbon dioxide; it also contains 2.7% nitrogen, 1.6% argon, 0.13% oxygen, 0.1% water vapor, 0.07% carbon monoxide. There are traces of methane.

The Martian ionosphere extends from 110 to 130 km above the surface of the planet.

There is evidence that in the past the atmosphere could be denser, and the climate warm and humid, and liquid water existed on the surface of Mars and it rained. The Mars Odyssey orbiter has discovered that there are deposits of water ice under the surface of the red planet. Later this assumption was confirmed by other devices, but the question of the presence of water on Mars was finally resolved in 2008, when the Phoenix probe, which landed near north pole planet, received water from the Martian soil.

The climate, like on Earth, is seasonal. In the cold season, even outside the polar caps, light frost can form on the surface. The Phoenix device recorded snowfall, but the snowflakes evaporated before reaching the surface.

According to researchers from the Carl Sagan Center, the process of warming has been going on on Mars in recent decades. Other experts believe that it is too early to draw such conclusions.

The Opportunity rover recorded numerous dust whirlwinds. These are air turbulences that occur near the surface of the planet and raise a large amount of sand and dust into the air. They are often observed on Earth, but on Mars they can reach much larger sizes.

Two-thirds of the surface of Mars is occupied by light areas, called continents, about a third - by dark areas, called seas. The seas are concentrated mainly in the southern hemisphere of the planet, between 10 and 40 ° latitude. There are only two large seas in the northern hemisphere - the Acidalian and the Great Syrt.

The nature of the dark areas is still a matter of controversy. They persist despite the fact that dust storms rage on Mars. At one time, this served as an argument in favor of the assumption that the dark areas are covered with vegetation. Now it is believed that these are just areas from which, due to their relief, dust is easily blown out. Large-scale images show that in fact, the dark areas consist of groups of dark bands and spots associated with craters, hills and other obstacles in the path of the winds. Seasonal and long-term changes in their size and shape are apparently associated with a change in the ratio of surface areas covered with light and dark matter.

The hemispheres of Mars are quite different in the nature of the surface. In the southern hemisphere, the surface is 1–2 km above the mean level and is densely dotted with craters. This part of Mars resembles the lunar continents. In the north, most of the surface is below average, there are few craters, and the main part is occupied by relatively smooth plains, probably formed as a result of lava flooding and erosion. This difference between the hemispheres remains a matter of debate. The boundary between the hemispheres follows approximately a great circle inclined at 30° to the equator. The boundary is wide and irregular and forms a slope towards the north. Along it there are the most eroded areas of the Martian surface.

Two alternative hypotheses have been put forward to explain the asymmetry of the hemispheres. According to one of them, at an early geological stage, the lithospheric plates "came together" (perhaps by accident) into one hemisphere, like the Pangea continent on Earth, and then "frozen" in this position. Another hypothesis involves the collision of Mars with a space body the size of Pluto.

A large number of craters in the southern hemisphere suggests that the surface here is ancient - 3-4 billion years. There are several types of craters: large craters with a flat bottom, smaller and younger cup-shaped craters similar to the moon, craters surrounded by a rampart, and elevated craters. The latter two types are unique to Mars - rimmed craters formed where liquid ejecta flowed over the surface, and elevated craters formed where a crater ejecta blanket protected the surface from wind erosion. The largest feature of impact origin is the Hellas Plain (about 2100 km across).

In a region of chaotic landscape near the hemispheric boundary, the surface experienced large areas of fracture and compression, sometimes followed by erosion (due to landslides or catastrophic release of groundwater) and flooding with liquid lava. Chaotic landscapes are often found at the head of large channels cut by water. The most acceptable hypothesis for their joint formation is the sudden melting of subsurface ice.

In the northern hemisphere, in addition to vast volcanic plains, there are two areas of large volcanoes - Tharsis and Elysium. Tharsis is a vast volcanic plain with a length of 2000 km, reaching a height of 10 km above the average level. There are three large shield volcanoes on it - Mount Arsia, Mount Pavlina and Mount Askriyskaya. On the edge of Tharsis is the highest mountain on Mars and in the solar system, Mount Olympus. Olympus reaches 27 km in height in relation to its base and 25 km in relation to the average level of the surface of Mars, and covers an area of 550 km in diameter, surrounded by cliffs, in places reaching 7 km in height. The volume of Mount Olympus is 10 times the volume of the largest volcano on Earth, Mauna Kea. Several smaller volcanoes are also located here. Elysium - a hill up to six kilometers above the average level, with three volcanoes - the dome of Hecate, Mount Elysius and the dome of Albor.

The Tharsis Upland is also crossed by many tectonic faults, often very complex and extended. The largest of them, the Mariner valleys, stretches in a latitudinal direction for almost 4000 km (a quarter of the planet's circumference), reaching a width of 600 km and a depth of 7-10 km; this fault is comparable in size to the East African Rift on Earth. On its steep slopes, the largest landslides in the solar system occur. The Mariner Valleys are the largest known canyon in the solar system. The canyon, which was discovered by the Mariner 9 spacecraft in 1971, could cover the entire territory of the United States, from ocean to ocean.

The appearance of Mars varies greatly depending on the time of year. First of all, changes in the polar caps are striking. They grow and shrink, creating seasonal phenomena in the atmosphere and on the surface of Mars. The southern polar cap can reach a latitude of 50°, the northern one also 50°. The diameter of the permanent part of the northern polar cap is 1000 km. As the polar cap in one of the hemispheres recedes in spring, details of the planet's surface begin to darken. To a terrestrial observer, the darkening wave appears to be propagating from the polar cap towards the equator, although the orbiters do not record any significant changes.

The polar caps are made up of two components: seasonal carbon dioxide and secular water ice. According to the Mars Express satellite, the thickness of the caps can range from 1 m to 3.7 km. The Mars Odyssey spacecraft has discovered active geysers on the south polar cap of Mars. As NASA experts believe, jets of carbon dioxide with spring warming break up to a great height, taking dust and sand with them.

The spring melting of the polar caps leads to a sharp increase in atmospheric pressure and the movement of large masses of gas to the opposite hemisphere. The speed of the winds blowing at the same time is 10-40 m/s, sometimes up to 100 m/s. The wind raises a large amount of dust from the surface, which leads to dust storms. Strong dust storms almost completely hide the surface of the planet. Dust storms have a noticeable effect on the temperature distribution in the Martian atmosphere.

Data from the Martian Reconnaissance Satellite made it possible to detect a significant layer of ice under the scree at the foot of the mountains. The glacier hundreds of meters thick covers an area of thousands of square kilometers, and its further study can provide information about the history of the Martian climate.

On Mars, there are many geological formations that resemble water erosion, in particular, dried up river beds. According to one hypothesis, these channels could have formed as a result of short-term catastrophic events and are not proof of the long-term existence of the river system. However, recent evidence suggests that the rivers have flowed for geologically significant periods of time. In particular, inverted channels (that is, channels elevated above the surrounding area) have been found. On Earth, such formations are formed due to the long-term accumulation of dense bottom sediments, followed by drying and weathering of the surrounding rocks. In addition, there is evidence of channel shifting in the river delta as the surface gradually rises.

Data from NASA's Spirit and Opportunity rovers also provide evidence for the presence of water in the past (minerals found that could only form as a result of prolonged exposure to water). The device "Phoenix" discovered deposits of ice directly in the ground.

Several unusual deep wells have been found on the Tharsis volcanic upland. Judging by the image of the Martian Reconnaissance Satellite, taken in 2007, one of them has a diameter of 150 meters, and the illuminated part of the wall goes no less than 178 meters deep. A hypothesis about the volcanic origin of these formations has been put forward.

The elemental composition of the surface layer of the Martian soil, according to the data of the landers, is not the same in different places. The main component of the soil is silica (20-25%), containing an admixture of iron oxide hydrates (up to 15%), which give the soil a reddish color. There are significant impurities of sulfur compounds, calcium, aluminum, magnesium, sodium (a few percent for each).

According to data from NASA's Phoenix probe (landing on Mars on May 25, 2008), the pH ratio and some other parameters of Martian soils are close to Earth's, and plants could theoretically be grown on them. "In fact, we found that the soil on Mars meets the requirements, and also contains the necessary elements for the emergence and maintenance of life in the past, present and future." “We were pleasantly surprised by the data received. This type of soil is also widely represented on Earth - any villager deals with it daily in the garden. A high (significantly higher than expected) content of alkalis was noted in it, and ice crystals were found. Such soil is quite suitable for growing various plants, such as asparagus. There is nothing here to make life impossible. On the contrary: with each new study, we find additional evidence in favor of the possibility of its existence, ”said Sam Kunaves, lead research chemist of the project.

There is also a significant amount of water ice in the ground at the landing site of the apparatus.

Unlike Earth, there is no movement on Mars lithospheric plates. As a result, volcanoes can exist for a much longer time and reach gigantic sizes.

Modern models of the internal structure of Mars suggest that Mars consists of a crust with an average thickness of 50 km (and a maximum thickness of up to 130 km), a silicate mantle 1800 km thick, and a core with a radius of 1480 km. The density in the center of the planet should reach 8.5 g/cm³. The core is partially liquid and consists mainly of iron with an admixture of 14-17% (by mass) of sulfur, and the content of light elements is twice as high as in the Earth's core. According to modern estimates, the formation of the core coincided with the period of early volcanism and lasted about a billion years. The partial melting of mantle silicates took approximately the same time. Due to the lower gravity on Mars, the pressure range in the mantle of Mars is much smaller than on Earth, which means that it has fewer phase transitions. It is assumed that the phase transition of olivine to spinel modification begins at fairly large depths - 800 km (400 km on Earth). The nature of the relief and other features suggest the presence of an asthenosphere consisting of zones of partially molten matter. For some regions of Mars, a detailed geological map has been compiled.

According to observations from orbit and analysis of the collection of Martian meteorites, the surface of Mars consists mainly of basalt. There is some evidence to suggest that, on part of the Martian surface, the material is more quartz-bearing than normal basalt and may be similar to andesitic rocks on Earth. However, these same observations can be interpreted in favor of the presence of quartz glass. A significant part of the deeper layer consists of granular iron oxide dust.

Mars has a magnetic field, but it is weak and extremely unstable, at different points on the planet its strength can differ from 1.5 to 2 times, and the magnetic poles do not coincide with the physical ones. This suggests that the iron core of Mars is relatively immobile in relation to its crust, that is, the planetary dynamo mechanism responsible for the Earth's magnetic field does not work on Mars. Although Mars does not have a stable planetary magnetic field, observations have shown that parts of the planet's crust are magnetized and that there has been a reversal of the magnetic poles of these parts in the past. The magnetization of these parts turned out to be similar to strip magnetic anomalies in the oceans.

One theory, published in 1999 and re-examined in 2005 (using the unmanned Mars Global Surveyor), is that these bands show plate tectonics 4 billion years ago, before the planet's dynamo ceased to function, causing a sharp weakening magnetic field. The reasons for this sharp decline are unclear. There is an assumption that the functioning of the dynamo 4 billion. years ago is explained by the presence of an asteroid that rotated at a distance of 50-75 thousand kilometers around Mars and caused instability in its core. The asteroid then dropped to its Roche limit and collapsed. However, this explanation itself contains ambiguities, and is disputed in the scientific community.

Perhaps, in the distant past, as a result of a collision with a large celestial body, the rotation of the core stopped, as well as the loss of the main volume of the atmosphere. It is believed that the loss of the magnetic field occurred about 4 billion years ago. Due to the weak magnetic field, the solar wind penetrates the atmosphere of Mars almost unhindered, and many of the photochemical reactions under the action of solar radiation that occur on Earth in the ionosphere and above can be observed on Mars almost at its very surface.

The geological history of Mars includes the following three epochs:
Noachian Epoch (named after "Noachian Land", a region of Mars): Formation of the oldest extant surface of Mars. It continued in the period 4.5 billion - 3.5 billion years ago. During this epoch, the surface was scarred by numerous impact craters. The plateau of the province of Tharsis was probably formed during this period with intense water flow later.
Hesperian epoch: from 3.5 billion years ago to 2.9 - 3.3 billion years ago. This era is marked by the formation of huge lava fields.
Amazonian Epoch (named after the "Amazonian Plain" on Mars): from 2.9 - 3.3 billion years ago to the present day. The regions formed during this epoch have very few meteorite craters, but otherwise they are completely different. Mount Olympus was formed during this period. At this time, lava flows were pouring in other parts of Mars.

The natural satellites of Mars are Phobos and Deimos. Both were discovered by the American astronomer Asaph Hall in 1877. Phobos and Deimos are irregularly shaped and very small. According to one hypothesis, they may represent asteroids like (5261) Eureka from the Trojan group of asteroids captured by the gravitational field of Mars. The satellites are named after the characters accompanying the god Ares (that is, Mars), Phobos and Deimos, personifying fear and horror, who helped the god of war in battles.

Both satellites rotate around their axes with the same period as around Mars, therefore they are always turned to the planet by the same side. The tidal influence of Mars gradually slows down the movement of Phobos, and eventually will lead to the fall of the satellite to Mars (while maintaining the current trend), or to its disintegration. On the contrary, Deimos is moving away from Mars.

Phobos (top) and Deimos (bottom).

Both satellites have a shape approaching a triaxial ellipsoid, Phobos (26.6 × 22.2 × 18.6 km) is slightly larger than Deimos (15 × 12.2 × 10.4 km). The surface of Deimos looks much smoother due to the fact that most of the craters are covered with fine-grained matter. Obviously, on Phobos, which is closer to the planet and more massive, the substance ejected during meteorite impacts either struck again on the surface or fell on Mars, while on Deimos it remained in orbit around the satellite for a long time, gradually settling and hiding uneven terrain.

The popular idea that Mars was inhabited by intelligent Martians became widespread in the late 19th century. Schiaparelli's observations of the so-called canals, combined with Percival Lowell's book on the same subject, popularized the idea of a planet that was becoming drier, colder, dying, and in which ancient civilization performing irrigation works.

Numerous other sightings and announcements by famous people gave rise to the so-called "Mars Fever" around this topic. In 1899, while studying atmospheric interference in a radio signal using receivers at the Colorado Observatory, inventor Nikola Tesla observed a repeating signal. He then speculated that it might be a radio signal from other planets such as Mars. In a 1901 interview, Tesla said that the idea came to him that interference could be caused artificially. Although he could not decipher their meaning, it was impossible for him that they arose completely by chance. In his opinion, it was a greeting from one planet to another.

Tesla's theory was enthusiastically supported by Lord Kelvin, who, visiting the US in 1902, said that he thought Tesla had picked up the Martian signal sent to the US. However, Kelvin then vehemently denied this statement before he left America: "In fact, I said that the inhabitants of Mars, if they exist, can certainly see New York, in particular the light from electricity."

Today, the presence of liquid water on its surface is considered a condition for the development and maintenance of life on the planet. There is also a requirement that the planet's orbit be in the so-called habitable zone, which for the solar system begins behind Venus and ends with the semi-major axis of the orbit of Mars. During perihelion, Mars is within this zone, but a thin atmosphere with low pressure prevents the appearance of liquid water over a large area for a long period. Recent evidence suggests that any water on the surface of Mars is too salty and acidic to support permanent terrestrial life.

The lack of a magnetosphere and the extremely thin atmosphere of Mars are also a problem for sustaining life. There is a very weak movement of heat flows on the surface of the planet, it is poorly isolated from bombardment by solar wind particles, in addition, when heated, water instantly evaporates, bypassing the liquid state due to low pressure. Mars is also on the threshold of the so-called. "geological death". The end of volcanic activity apparently stopped the circulation of minerals and chemical elements between the surface and the interior of the planet.

Evidence suggests that the planet was previously much more prone to life than it is now. However, to date, the remains of organisms have not been found on it. Under the Viking program, carried out in the mid-1970s, a series of experiments were conducted to detect microorganisms in the Martian soil. It has shown positive results, such as a temporary increase in CO2 release when soil particles are placed in water and nutrient media. However, then this evidence of life on Mars was disputed by some scientists. This led to their lengthy dispute with NASA scientist Gilbert Lewin, who claimed that the Viking had discovered life. After re-evaluating the Viking data in the light of current scientific knowledge about extremophiles, it was determined that the experiments carried out were not perfect enough to detect these life forms. Moreover, these tests could even kill the organisms, even if they were contained in the samples. Tests conducted by the Phoenix Program have shown that the soil has a very alkaline pH and contains magnesium, sodium, potassium and chloride. The nutrients in the soil are sufficient to support life, but life forms must be protected from intense ultraviolet light.

Interestingly, in some meteorites of Martian origin, formations were found that resemble the simplest bacteria in shape, although they are inferior to the smallest terrestrial organisms in size. One of these meteorites is ALH 84001, found in Antarctica in 1984.

According to the results of observations from the Earth and data from the Mars Express spacecraft, methane was detected in the atmosphere of Mars. Under the conditions of Mars, this gas decomposes rather quickly, so there must be a constant source of replenishment. Such a source can be either geological activity (but no active volcanoes have been found on Mars), or the vital activity of bacteria.

After the landings of automatic vehicles on the surface of Mars, it became possible to conduct astronomical observations directly from the surface of the planet. Due to the astronomical position of Mars in the solar system, the characteristics of the atmosphere, the period of revolution of Mars and its satellites, the picture of the night sky of Mars (and astronomical phenomena observed from the planet) differs from the earth's and in many ways seems unusual and interesting.

During sunrise and sunset, the Martian sky at the zenith has a reddish-pink color, and in close proximity to the disk of the Sun - from blue to purple, which is completely opposite to the picture of earthly dawns.

At noon, the sky of Mars is yellow-orange. The reason for such differences from the color scheme of the earth's sky is the properties of the thin, rarefied atmosphere of Mars containing suspended dust. On Mars, Rayleigh scattering of rays (which on Earth is the cause of the blue color of the sky) plays an insignificant role, its effect is weak. Presumably, the yellow-orange coloration of the sky is also caused by the presence of 1% magnetite in dust particles constantly suspended in the Martian atmosphere and raised by seasonal dust storms. Twilight begins long before sunrise and lasts long after sunset. Sometimes the color of the Martian sky acquires a purple hue as a result of light scattering on microparticles of water ice in clouds (the latter is a rather rare phenomenon).

Earth is an inner planet to Mars, just like Venus is to Earth. Accordingly, from Mars, the Earth is observed as morning or evening Star, rising before dawn or visible in the evening sky after sunset.

The maximum elongation of the Earth in the sky of Mars will be 38 degrees. To the naked eye, the Earth will be visible as a bright (maximum visible stellar magnitude of about −2.5) greenish star, next to which the yellowish and dimmer (about 0.9) star of the Moon will be easily distinguishable. In a telescope, both objects will show the same phases. The revolution of the Moon around the Earth will be observed from Mars as follows: at the maximum angular distance of the Moon from the Earth, the naked eye will easily separate the Moon and the Earth: in a week the “stars” of the Moon and the Earth will merge into a single star inseparable by the eye, in another week the Moon will again be visible at maximum distance, but on the other side of the Earth. Periodically, an observer on Mars will be able to see the passage (transit) of the Moon across the Earth's disk or, conversely, the covering of the Moon by the Earth's disk. The maximum apparent distance of the Moon from the Earth (and their apparent brightness) when viewed from Mars will vary significantly depending on the relative position of the Earth and Mars, and, accordingly, the distance between the planets. In the epoch of oppositions, it will be about 17 minutes of arc, at the maximum distance of Earth and Mars - 3.5 minutes of arc. Earth, like other planets, will be observed in the constellation band of the Zodiac. An astronomer on Mars will also be able to observe the passage of the Earth across the disk of the Sun, the next one will occur on November 10, 2084.

The angular size of the Sun, observed from Mars, is less than that visible from the Earth and is 2/3 of the latter. Mercury from Mars will be practically inaccessible to observation with the naked eye due to its extreme proximity to the Sun. The brightest planet in the sky of Mars is Venus, in second place is Jupiter (its four largest satellites can be observed without a telescope), in third is Earth.

Phobos, when observed from the surface of Mars, has an apparent diameter of about 1/3 of the disk of the Moon in the earth's sky and an apparent magnitude of the order of −9 (approximately like the Moon in the phase of the first quarter). Phobos rises in the west and sets in the east, only to rise again 11 hours later, thus crossing the sky of Mars twice a day. The movement of this fast moon across the sky will be easily seen during the night, as will the changing phases. Naked eye will distinguish the largest detail of the relief of Phobos - the crater Stickney. Deimos rises in the east and sets in the west, looks like bright Star without a noticeable visible disk, with a magnitude of about −5 (slightly brighter than Venus in the Earth's sky), slowly crossing the sky for 2.7 Martian days. Both satellites can be observed in the night sky at the same time, in which case Phobos will move towards Deimos.

The brightness of both Phobos and Deimos is sufficient for objects on the surface of Mars to cast sharp shadows at night. Both satellites have a relatively small inclination of the orbit to the equator of Mars, which excludes their observation in the high northern and southern latitudes of the planet: for example, Phobos never rises above the horizon north of 70.4 ° N. sh. or south of 70.4°S sh.; for Deimos these values are 82.7°N. sh. and 82.7°S sh. On Mars, an eclipse of Phobos and Deimos can be observed when they enter the shadow of Mars, as well as an eclipse of the Sun, which is only annular due to the small angular size of Phobos compared to the solar disk.

The north pole on Mars, due to the tilt of the planet's axis, is in the constellation Cygnus (equatorial coordinates: right ascension 21h 10m 42s, declination +52° 53.0' and is not marked by a bright star: the nearest to the pole is a dim star of the sixth magnitude BD +52 2880 (other its designations are HR 8106, HD 201834, SAO 33185. The south celestial pole (coordinates 9h 10m 42s and −52° 53.0) is a couple of degrees from the star Kappa Parusov (apparent magnitude 2.5) - its, in principle , can be considered South polar star Mars.

The zodiac constellations of the Martian ecliptic are similar to those observed from the Earth, with one difference: when observing the annual movement of the Sun among the constellations, it (like other planets, including the Earth), leaving the eastern part of the constellation Pisces, will pass for 6 days through the northern part of the constellation Cetus before how to re-enter the western part of Pisces.

Due to the proximity of Mars to Earth, its colonization in the foreseeable future is an important task for humanity. Relatively close to Earth natural conditions make this task easier. In particular, on Earth there are such places explored by man, in which the natural conditions are in many ways similar to those on Mars. Atmosphere pressure at an altitude of 34,668 meters - the highest point reached by a balloon with a crew on board (May 1961) - approximately corresponds to the pressure on the surface of Mars. Extremely low temperatures in the Arctic and Antarctica are comparable even to the lowest temperatures on Mars, and on the equator of Mars in the summer months it is as warm (+30 ° C) as on Earth. Also on Earth there are deserts similar in appearance to the Martian landscape.

However, there are several significant differences between Earth and Mars. In particular, the magnetic field of Mars is weaker than the earth's by about 800 times. Together with a rarefied atmosphere, this increases the amount of ionizing radiation reaching its surface. Radiation measurements carried out by the American unmanned spacecraft The Mars Odyssey showed that the radiation background in the orbit of Mars is 2.2 times higher than the radiation background at the International space station. The average dose was approximately 220 millirads per day (2.2 milligrays per day or 0.8 grays per year). The amount of exposure received as a result of being in such a background for three years, approaches the established safety limits for astronauts. On the surface of Mars, the radiation background will most likely be somewhat lower and may vary significantly depending on the terrain, altitude and local magnetic fields.

Mars has a certain economic potential for colonization. In particular, the southern hemisphere of Mars was not subjected to melting, unlike the entire surface of the Earth - therefore, the rocks of the southern hemisphere inherited the quantitative composition of the non-volatile component of the protoplanetary cloud. According to calculations, it should be enriched with those elements (relative to the Earth) that on Earth “drowned” in its core during the melting of the planet: metals of the copper, iron and platinum groups, tungsten, rhenium, uranium. The export of rhenium, platinum metals, silver, gold and uranium to the Earth (in the event of an increase in prices for it to the level of prices for silver) has good prospects, but for its implementation it requires the presence of a surface reservoir with liquid water for enrichment processes.

The flight time from Earth to Mars (with current technologies) is 259 days in a semi-ellipse and 70 days in a parabola. To communicate with potential colonies, radio communication can be used, which has a delay of 3-4 minutes in each direction during the closest approach of the planets (the opposition of Mars, from an earthly point of view, which repeats every 780 days), and about 20 minutes. at the maximum removal of the planets (the conjunction of Mars with the Sun); see Configuration (astronomy).

However, to date, no practical steps have been taken towards the colonization of Mars.

The exploration of Mars began a long time ago, even 3.5 thousand years ago, in Ancient Egypt. The first detailed accounts of the position of Mars were made by Babylonian astronomers, who developed a number of mathematical methods to predict the position of the planet. Using the data of the Egyptians and Babylonians, ancient Greek (Hellenistic) philosophers and astronomers developed a detailed geocentric model to explain the movement of the planets. A few centuries later, Indian and Islamic astronomers estimated the size of Mars and its distance from Earth. In the 16th century, Nicolaus Copernicus proposed a heliocentric model to describe the solar system with circular planetary orbits. His results were revised by Johannes Kepler, who introduced a more accurate elliptical orbit for Mars, coinciding with the observed one.

Topographic map of Mars.

In 1659, Francesco Fontana, looking at Mars through a telescope, made the first drawing of the planet. He depicted a black spot in the center of a clearly defined sphere. In 1660, two polar caps were added to the black spot, added by Jean Dominique Cassini. In 1888, Giovanni Schiaparelli, who studied in Russia, gave the first names to individual surface details: the seas of Aphrodite, Eritrean, Adriatic, Cimmerian; lakes of the Sun, Lunar and Phoenix.

The heyday of telescopic observations of Mars fell on late XIX- mid-twentieth century. It is largely due to public interest and well-known scientific disputes around the observed Martian channels. Among the astronomers of the pre-space era who made telescopic observations of Mars during this period, the most famous are Schiaparelli, Percival Lovell, Slifer, Antoniadi, Barnard, Jarry-Deloge, Tikhov, Vaucouleurs. It was they who laid the foundations of areography and compiled the first detailed maps the surface of Mars - although they turned out to be almost completely wrong after flights to Mars by automatic probes.

Orbital characteristics:
Perihelion
206.62×106 km
1.3812 a. e.
Aphelion
249.23×106 km
1.6660 a. e.
Major axle (a)
227.92×106 km
1.5236 a. e.
Orbital eccentricity (e)
0,093315
sidereal period
686.971 days
1.8808 Earth years
Sol 668.5991
Synodic period of circulation
779.94 days
Orbital speed (v)
24.13 km/s (average)
Inclination (i)
1.85061° (relative to the plane of the ecliptic)
5.65° (relative to solar equator)
Ascending node longitude (Ω)
49.57854°
Periapsis argument (ω)
286.46230°

Satellites:
2 (Phobos and Deimos)
physical characteristics
flattening
0,00589
Equatorial radius
3396.2 km
Polar radius
3376.2 km
Medium radius
3386.2 km
Surface area (S)
144,798,465 km²
Volume (V)
1.6318×1011 km³
0.151 Earth
Weight (m)
6.4185×1023 kg
0.107 Earth
Average density (ρ)
3.9335 g/cm³
Acceleration of gravity at the equator (g)
3.711 m/s² (0.378 g)
Second escape velocity (v2)
5.027 km/s
Equatorial rotation speed
868.22 km/h
Rotation period (T)
24 hours 39 minutes and 36 seconds
Axis Tilt
24.94°
Right ascension north pole (α)
21 h 10 min 44 s
317.68143°
North Pole Declination (δ)
52.88650°
Albedo
0.250 (Bond)
0.150 (geom.albedo)

Temperature:

min. avg. Max.

Worldwide 186 K 227 K 268 K

Atmosphere:
Atmosphere pressure
0.6-1.0 kPa (0.006-0.01 atm)
Compound:
95.32% ar. gas

2.7% Nitrogen
1.6% Argon
0.2% oxygen
0.07% Carbon monoxide
0.03% Water vapor
0.01% Nitric oxide

Among the objects of the solar system, Mars continues to be the most curious and most explored planet. For all the time of close study by man of our near space, only the fourth planet of the solar system has received such attention. The reason for such an increased interest in our neighbor lies not only in its relative proximity to our world. The red planet is of interest to humanity in terms of the possibility of exploring extraterrestrial space.

The data that is available today about Mercury and Venus indicate that these are alien, hostile worlds for us. For these planets, nature has prepared the fate of physical and chemical laboratories. Mars, in many respects, is no longer so gloomy and lifeless. It is not for nothing that the literary laurels of the birthplace of the first extraterrestrial civilization belong to this planet. Why is Mars so interesting to us? What is a person really dealing with, turning his gaze to a small, reddish star in the night sky.

Description of the red planet

Of the entire list of planets in the solar system, Mars is perhaps the only one space object, which a person can reach today. It is the second closest planet to us in the solar system. Even the level of technological development that human civilization has reached makes it possible to make plans for the exploration of Mars and the implementation of a manned flight to the fourth planet of our star system. Approximately for the implementation of this large-scale and grandiose program, it will take another 10-15 years. However, if we compare the preparatory measures now under way in this direction with the program for a visit by man to the Moon, the difference is obvious.

According to many data obtained in Lately with the help of robotic space probes and rovers, it is possible that life could have existed on the red planet millions of years ago. Not without reason, studying the obtained images of the surface of the planet Mars, scientists of all stripes are unanimous in their opinion - our neighbor is not hopeless. There are all prerequisites to believe that the fourth planet could be another oasis of life in our solar system. This is facilitated by the astrophysical parameters of the planet, data on the Martian atmosphere, and the climatic pattern on the surface of our neighbor.

In addition, if the Martian poles are covered with ice caps, the version about the presence of liquid water in the bowels of the planet has the right to life. If it is proved that liquid water has every chance of being in the nature of the red planet, then the question of finding life forms in this harsh place is just a matter of time.

Confidence to supporters of the usefulness of Mars for human exploration is given by information about the composition of the Martian air and astrophysical parameters similar to those of the Earth. Even under the condition that the atmosphere of the planet is far in its composition from the earth's air gap, we can talk about relatively acceptable conditions. A highly rarefied atmosphere does not inspire optimism, but to some extent it is better than the picture that we observe on Mercury or on hot Venus. Scientists believe that according to climatic parameters on Mars, the weather is quite tolerable. Severe frosts with temperatures down to -170°C in the polar regions give way to tropical heat in the equatorial regions. In summer days the temperature reaches +20°C. However, in winter time and especially at night, the temperature can drop to -125°C.

In other words, with the appropriate technical and physical training man, the Martian environment may be habitable. Do not discount the fact that such climatic conditions were the result of a cosmic cataclysm. It is possible that in the distant past of the planet, the climate on the planet was warmer and Martian life was rampant on the planet. This cannot be said in relation to other planets of the terrestrial group, where the slightest hints of the existence of conditions for the origin of life are completely absent.

The information that the scientific community has collected today gives every reason to consider the Red Planet as a convenient springboard for subsequent space exploration. Numerous works of scientists, flights of automatic probes to the planet and delivery of rovers to Mars made it possible to obtain mass useful information. We now know almost everything about the Martian soil, we have an idea of the most severe dust storms. Scientists have obtained detailed images of almost the entire surface of the planet, including the northern and southern polar caps. It remains only to process the tons of information received and draw the appropriate conclusions.

Brief description and features of the planet

From the point of view of academic science, Mars is a pronounced terrestrial planet. The slightly elongated orbit of the planet is located 1.5 times farther from the Sun than the orbit of the Earth. At perihelion, Mars moves away from our star at a distance of 250 million km, and at aphelion, the planet Mars is separated from the Sun by a distance of 207 million km. The Red Planet is twice the size of our Earth. The diameter of the fourth planet is 6,779 km, against 12,742 km. Earth's diameter.

If Mars is only twice as large as Earth, then the mass of the Red Planet is ten times lighter than our blue beauty, 6.39E23 kg versus 5.972E24 kg. Accordingly, the free fall acceleration of our neighbor is only 3.72 m/s2 against 9.807 m/s2. For all its miniature size, the relief of the planet is quite diverse. The Red Planet has mountains and valleys, vast depressions, deep canyons, and even meteorite craters similar to moon formations. Extinct volcanoes have been discovered on the surface of our neighbor, indicating the stormy youth of Mars. Here is the highest volcano in the solar system - Mount Olympus. Its top rests against the Martian sky, reaching 26 kilometers in height. This extinct volcano holds the record, with a height of 2.5 times the relative height of the terrestrial volcano Mauna Kea.

However, despite the varied terrain, the landscape on Mars is rather boring and monotonous. mountain ranges replaced by endless rocky deserts. The bright areas on the surface of the planet are called the continents, while the dark areas are the Martian seas. These elements of the Martian relief occupy more than 70% of the area of the southern hemisphere of Mars.

With all the monotony of the Martian surface, the planet has its own feature. Both hemispheres of Mars differ significantly both in morphological features and in terms of the intensity of external influence. In the northern hemisphere, the relief is dominated by valleys and smooth plains, although the surface of the planet in this part is below average. The southern hemisphere is dominated by meteorite craters and the surface itself is elevated. This fact to some extent explains the presence of tectonic plates that moved in ancient times. The dull Martian landscape is brightened up only by the polar caps that are available on the northern and south pole planets.

Like all terrestrial planets, Mars has a classical structure:

crust, 100 km thick at the poles and 8 km thick in the equatorial region in the region of the Hellas depression;
an intermediate layer consisting of semi-liquid rocks;
silicate mantle 1300-1500 km thick;
an iron core with a diameter of 2960 km, which is half liquid.

The Red Planet has its own atmosphere. Its composition is dominated by carbon dioxide. To a lesser extent, the air mass of the planet contains nitrogen, hydrogen and oxygen. The presence of water vapor is very limited. Due to the strong rarefaction, the atmospheric pressure on Mars is 150 times less than the earth's pressure, only 6.1 millibars. The thickness of the gaseous shell around the planet is 110 km.

Assessing the physical information about the planet, it is worth paying attention to the astrophysical parameters of Mars, which are in many respects similar to the terrestrial parameters. The fourth planet makes a complete revolution around our star in 687 Earth days. At the same time, the speed of rotation of the red planet around own axis almost equal to the speed of rotation of the Earth - 24 hours and 37 minutes. In other words, time on the planet looks the same as on Earth. Due to its tilt and speed of rotation, Mars has a change of seasons, which is quite rare for other planets in the solar system. The length of the seasons on the surface of our neighbor is different. In the northern hemisphere, summer lasts 177 Martian days, while in the southern hemisphere, summer is 21 days shorter.

Brief description and nature of exploration of Mars

Since the first flights into space, man has not abandoned attempts to start studying neighboring planets. The American space probe Mariner 4 was the first to head to the Red Planet, which for the first time photographed Mars from a close distance, flying past the planet. Subsequent missions were already more thorough and applied in nature. The American probe "Mariner-9" having reached the fourth planet, became its first artificial satellite. In 1971, the first ever landing on Mars was made by the Soviet AMS "Mars-3". Despite a successful landing, the Soviet apparatus lived only 14 seconds. Subsequent attempts to land on Mars ended in failure.

Only the American AMS "Viking-1" once again managed to make a soft landing on the planet and provide man with the first pictures of the surface of Mars. During the same expedition, for the first time, samples of Martian soil were taken by the apparatus and data on the composition of the soil were obtained. Further, with enviable regularity, Soviet and American spacecraft, automatic probes of space agencies of different countries, including China, Japan and the European Community. Over the next 45 years from the moment of the first flight of Mariner-4 towards Mars, 48 expeditions to the Red Planet were organized from the Earth. Of this number, almost half of the missions ended in failures.

To date, the following devices continue to explore the planet:

the orbital satellite of Mars - the American apparatus "Mars-Odyssey";
from the planet's orbit, the automatic probe of the European Space Agency "Mars-Express";
American orbiter "Maven" and a satellite of the military department;
the Indian orbital probe "Mangalyan" and the space probe "Trace gas Orbiter" of ESA and Roscosmos.

Directly on the planet, two American rovers Opportunity and Curiosity continue to work, which have already become legendary creations of human thought. Numerous space probes, automatic Martian stations and rovers - all this equipment is an arsenal thrown by the scientific community to study the red planet.

Permanent satellites of Mars

Mars, despite its size, has two natural satellites - Phobos and Deimos, triaxial ellipsoids with dimensions of 26.8 × 22.4 × 18.4 km and 15 × 12.2 × 10.4 km, respectively.

The exact origin of these celestial bodies is unknown. The size of the Martian satellites and their shape cause numerous disputes among supporters. various theories origin of Phobos and Deimos. It is assumed that these are asteroids captured by the red planet at the dawn of the formation of the solar system. The supplier of material for the satellites of Mars is the asteroid belt, located between the fourth planet and Jupiter.

Proponents of another version of the origin of the satellites of the red planet are inclined to their artificial nature. The ancient Martian civilization could create and launch two artificially created celestial bodies.

Mars is one of the first planets in the solar system discovered by mankind. To date, of all eight planets, it is Mars that has been studied in the most detail. But this does not stop researchers, but on the contrary, it is causing more and more interest in the "Red Planet" and its study.

Why is it called so?

The planet got its name from Mars - one of the most revered gods of the ancient Roman pantheon, which, in turn, is a reference to the Greek god Ares, the patron saint of cruel and treacherous war. This name was not chosen at all by chance - the reddish surface of Mars resembles the color of blood and involuntarily makes you remember the lord of bloody battles.

The names of the two satellites of the planet also bear deep meaning. The words "Phobos" and "Deimos" in Greek mean "Fear" and "Horror", that is the name of the two sons of Ares, who, according to legend, always accompanied their father in battle.

Brief history of learning

For the first time, mankind began to observe Mars by no means through telescopes. Even the ancient Egyptians noticed the Red Planet as a wandering object, which is confirmed by ancient written sources. The Egyptians were the first to calculate the trajectory of Mars relative to the earth.

Then the baton was taken over by astronomers Babylonian kingdom. Scientists from Babylon were able to more accurately determine the location of the planet and measure the time of its movement. The Greeks were next. They managed to create an accurate geocentric model and use it to understand the movement of the planets. Then the scientists of Persia and India were able to estimate the size of the Red Planet and its distance from the Earth.

A huge breakthrough was made by European astronomers. Johannes Kepler, based on the model of Nikolai Kaepernik, was able to calculate the elliptical orbit of Mars, and Christian Huygens created the first map of its surface and noticed an ice cap at the planet's north pole.

The advent of telescopes was the heyday in the study of Mars. Slipher, Barnard, Vaucouleur, and many other astronomers became the greatest explorers of Mars before man went into space.

Man's spacewalk made it possible to study the Red Planet more accurately and in detail. In the middle of the 20th century, with the help of interplanetary stations, accurate pictures of the surface were taken, and super-powerful infrared and ultraviolet telescopes made it possible to measure the composition of the planet's atmosphere and the speed of the winds on it.

In the future, more and more accurate studies of Mars by the USSR, the USA, and then other states followed.

The study of Mars continues to this day, and the data obtained only fuel interest in its study.

Characteristics of Mars

Mars is the fourth planet from the Sun, adjacent to the Earth on one side, and Jupiter on the other. In size, it is one of the smallest and surpasses only Mercury.
Mars' equator is slightly more than half the length of Earth's equator, and its surface area is approximately the same as Earth's land area.
There is a change of seasons on the planet, but their duration varies greatly. For example, summer in the northern part is long and cold, while in the southern part it is short and warmer.
The duration of a day is quite comparable with the earthly ones - 24 hours and 39 minutes, that is, a little more.

planet surface

No wonder the second name of Mars is the “Red Planet”. Indeed, from afar, its surface looks reddish-reddish. This shade of the surface of the planet gives red dust, which is contained in the atmosphere.

However, close up, the planet changes its color dramatically and no longer looks red, but yellow-brown. Sometimes other shades can be mixed with these colors: golden, reddish, greenish. The source of these shades are colored minerals, which are also present on Mars.

The main part of the planet's surface is made up of "continents" - clearly visible light areas, and a very small part - "seas", dark and poorly visible areas. Most of the "seas" are located in the southern hemisphere of Mars. The nature of the "seas" is still being disputed by researchers. But now scientists are most inclined to the following explanation: the dark areas are just bumps on the surface of the planet, namely craters, mountains and hills.

The following fact is extremely curious: the surface of the two hemispheres of Mars is very different.

The northern hemisphere is largely composed of smooth plains, its surface is below average.

The southern hemisphere is mostly cratered and its surface is above average.

Structure and geological data

The study of the magnetic field of Mars and the volcanoes that are located on its surface led scientists to an interesting conclusion: once on Mars, as on Earth, there was a movement of the lithosphere plates, which, however, is not observed now.

Modern researchers tend to think that the internal structure of Mars consists of the following components:

Bark (approximate thickness - 50 kilometers)
silicate mantle
Core (approximate radius - 1500 kilometers)
The core of the planet is partially liquid and contains twice as many light elements as the core of the Earth.

All about atmosphere

The atmosphere of Mars is very rarefied, and mainly consists of carbon dioxide. In addition, it includes: nitrogen, water vapor, oxygen, argon, carbon monoxide, xenon and many other elements.

The thickness of the atmosphere is approximately 110 kilometers. Atmospheric pressure at the surface of the planet is less than the earth's by more than 150 times (6.1 millibars).

The temperature on the planet fluctuates in a very wide range: from -153 to +20 degrees Celsius. The lowest temperatures occur at the pole in winter, the highest at the equator at noon. Average temperatures are around -50 degrees Celsius.

Interestingly, a thorough analysis of the Martian meteorite "ALH 84001" led scientists to the idea that a very long time ago (billions of years ago) the atmosphere of Mars was denser and more humid, and the climate was warmer.