What does the surface of Mars consist of? What does the surface of Mars look like?

Flickering in the days of confrontation with an ominous blood-red color and provoking a primordial mystical fear of the mysterious and mysterious star that the ancient Romans named in honor of the god of war Mars (among the Greeks Ares), it would hardly be a woman's name. The Greeks still called it Phaethon for the "radiant and shining" appearance, with which the surface of Mars owes a bright color and "lunar" relief with volcanic craters, dents from the impacts of giant meteorites, valleys and deserts.

Orbital characteristics

The eccentricity of the elliptic orbit of Mars is 0.0934, thus determining the difference between the maximum (249 million km) and the minimum (207 million km) distances to the Sun, which causes the amount of solar energy entering the planet to vary between 20-30%.

The speed of the orbit is on average 24.13 km / s. Mars completely encircles the Sun for 686.98 terrestrial days, which exceeds the Earth's period by a factor of two, and around its own axis it is almost the same as the Earth (in 24 hours 37 minutes). The angle of inclination of the orbit to the plane of the ecliptic varies from 1.51 ° to 1.85 °, and the inclination of the orbit to the equator is 1,093 °. Concerning the equator of the Sun, the orbit of Mars is inclined at an angle of 5.65 ° (and the Earth is about 7 °). The significant inclination of the planet's equator to the plane of the orbit (25.2 °) leads to significant seasonal climate changes.

Physical parameters of the planet

Mars among the planets of the solar system in size is in seventh place, and in remoteness from the Sun takes the fourth position. The planet's volume is 1.638 × 1011 km³, and the weight is 0.105-0.108 of the Earth's mass (6.44 * 1023 kg), yielding to it at a density of about 30% (3.95 g / cm ³ ). Acceleration of free fall in the area of the equator of Mars is determined in the range from 3,711 to 3,76 m / s². The surface area is estimated at 144,800,000 km². Atmospheric pressure fluctuates within 0.7-0.9 kPa. The speed needed to overcome gravity (the second space mission) is 5 072 m / s. In the southern hemisphere, the surface of Mars is 3-4 km higher in the average level than in the northern one.

Climatic conditions

The total mass of the atmosphere of Mars is about 2.5 * 1016 kg, but during the year it changes greatly due to the melting or "intent" of carbon- containing polar caps. The average pressure at the surface level (about 6.1 mbar) is almost 160 times smaller than near the surface of our planet, but in deep depressions it reaches 10 mbar. According to different sources, seasonal pressure differences range from 4.0 to 10 mbar.

At 95.32%, the atmosphere of Mars consists of carbon dioxide, about 4% is argon and nitrogen, and oxygen together with water vapor is less than 0.2%.

Strongly dissipated atmosphere can not hold heat for long. Despite the "hot color" that stands out among the other planet Mars, the surface temperature drops in winter to -160 ° C at the pole, and at the equator in the summer, in the daytime, the surface can only warm up to + 30 ° C.

The climate is seasonal in nature, as on Earth, but the elongation of the orbit of Mars leads to significant differences in the duration and temperature regime of the seasons. The cool spring and summer of the northern hemisphere collectively last much more than half of the Martian year (371 mars day), and winter with autumn are short and mild. The southern summer is hot and short, and the winter is cold and long.

Seasonal changes in climate are most clearly manifested in the behavior of polar caps composed of ice with an admixture of finely dispersed, pulverized rock particles. The front of the northern polar cap can be removed from the pole by almost a third of the distance to the equator, and the boundary of the southern cap reaches half of this distance.

A thermometer located exactly in the focus of a telescope-reflector aimed at Mars, the temperature on the surface of the planet was determined already in the early 20s of the last century. The first measurements (before 1924) showed values from -13 to -28 ° C, and in 1976 the lower and upper temperature limits were specified by the Viking spacecraft landing on Mars.

Martian dust storms

"Exposing" the dust storms, their scale and behavior allowed us to uncover the mystery that Mars kept for a long time. The surface of the planet mysteriously changes color, from a deep antiquity bewitching observers. The reason for the "chameleon" was dust storms.

Sharp changes in temperatures of the Red Planet cause the raging of violent winds, whose speed reaches 100 m / s, and low gravity, despite the rarefied air, allows the winds to lift huge dust masses to a height of more than 10 km.

The creation of dust storms is also facilitated by a sharp increase in atmospheric pressure caused by the evaporation of the frozen carbon dioxide of winter polar caps.

Dust storms, as the pictures of the surface of Mars show, spatially gravitate toward the polar caps and can cover enormous areas, lasting up to 100 days.

Another dusty attraction, which Mars owes to abnormal temperature changes, are tornadoes, which, unlike terrestrial "colleagues", walk around not only in desert areas, but also run on the slopes of volcano craters and percussion craters, meaning up to 8 km. Their traces were gigantic branched-striped drawings, which for a long time remained mysterious.

Dust storms and tornadoes occur mainly during the great confrontations, when in the southern hemisphere the summer falls on the period of the passage of Mars through the nearest to the Sun the point of the orbit of the planet (perihelion).

Very vivid on the tornadoes were the images of the surface of Mars, made spacecraft Mars Global Surveyor , which has been in orbit since 1997.

Some tornadoes leave traces, sweeping or sucking loose surface layer of fine particles of soil, others do not leave even "fingerprints", the third, raging, draw intricate figures, for which they were called dust devils. Vortices work, as a rule, alone, but also do not refuse from group "representations".

Features of the relief

Probably everyone who, armed with a powerful telescope, first glanced at Mars, the surface of the planet immediately reminded the lunar landscape, and in many areas this is true, but still the geomorphology of Mars is original and unique.

Regional features of the planet's relief are due to the asymmetry of its surface. The predominantly flat surfaces of the northern hemisphere are below the conditionally zero level for 2-3 km, and in the southern hemisphere complicated by craters, valleys, canyons, hollows and hills, the surface is 3-4 km above the baseline. The transition zone between two hemispheres of 100-500 km in width is morphologically expressed by a strongly eroded giant ledge almost 2 km high, covering almost 2/3 of the planet along the circumference and traced by the fault system.

The predominant relief forms characterizing the surface of Mars are represented by cratered craters of various genesis, elevations and depressions, percussion structures of circular depressions (multi-ring basins), linearly extended elevations (ridges) and steeply oblong hollows of irregular shape.

Widespread flat-topped uplifts with steep edges (table mountains), extensive flat craters (shield volcanoes) with eroded slopes, meandering valleys with tributaries and sleeves, leveled elevations (plateaus) and regions of randomly interspersed canyon-like valleys (labyrinths).

Characteristic for Mars are the disastrous depressions with a chaotic and formless relief, extended, complexly constructed steps (faults), a series of sub-parallel ridges and furrows, and extensive plains of a completely "earthly" appearance.

Ring crater basins and large (more than 15 km across) craters are the defining morphological structures for most of the southern hemisphere.

The highest regions of the planet with the names Farsida and Elysium are in the northern hemisphere and represent huge volcanic highlands. The plateau of Tarsida, towering over a flat environment of almost 6 km, stretches for 4,000 km in longitude and extends for 3000 km in latitude. On the plateau are 4 giant volcanoes with a height of 6.8 km (Alba Mountain) to 21.2 km (Olympus, diameter 540 km). Peaks of the Peacock / Pavonis mountains, Ascraeus and Arsia are at an altitude of 14, 18 and 19 km respectively. Mount Alba stands apart to the north-west of a strict number of other volcanoes and is a shield volcanic structure with a diameter of about 1500 km. The Olympus volcano is the highest mountain not only on Mars, but also in the entire Solar system.

From the east and west, two vast meridional lowlands adjoin the province of Farsida. The marks on the surface of the western plain with the name Amazonia are close to the zero level of the planet, and the lowest parts of the eastern depression (the Chrysea plain) are below the zero level by 2-3 km.

In the equatorial region of Mars, the second largest volcanic plateau of Elisius is about 1500 km across. The plateau rises above the base for 4-5 km and bears three volcanoes (Mount Eliziy proper, Albor dome and Hecate mountain). The highest mountain Eliziy grew to 14 km.

To the east of the Farsida Plateau, in the near-equatorial region, a giant-scale rift system of the valleys (canyons) Mariner stretches for almost 5 km, exceeding in length one of the largest on the land of the Grand Canyon by almost 10 times, and 7 times wider and deeper. The width of the valleys on the average is 100 km, and the almost vertical ledges of their sides reach a height of 2 km. Linearity of structures indicates their tectonic origin.

Within the elevations of the southern hemisphere, where the surface of Mars is simply strewn with craters, there are the largest circular shock depression on the planet with the names Argyr (about 1500 km) and Ellada (2300 km).

The Plain of Hellas is deeper than all the depressions of the planet (almost 7000 m below the average level), and the excess of the plain of Argyr in relation to the level of the surrounding elevation is 5.2 km. A similar rounded lowland, the plain of Isis (1100 km across), is located in the equatorial region of the eastern hemisphere of the planet and in the north it adjoins the plain of Elysium.

On Mars, there are about 40 similar multi-ring basins, but smaller ones.

AT Northern hemisphere is the largest on the planet lowland (Northern plain), bordering the polar region. Plain marks are below the zero level of the planet's surface.

Eolian landscapes

It would be difficult to describe the surface of the Earth in a few words, referring to the planet as a whole, but to get an idea of what kind of surface Mars can, if you just call it lifeless and dry, reddish-brown, rocky-sandy desert, because The dismembered relief of the planet is smoothed by loose alluvial deposits.

Eolian landscapes, composed of sandy-fine aleurite with dust and formed as a result of wind activity, cover almost the entire planet. These are ordinary (as on earth) barkhans (transverse, longitudinal and diagonal) in size from the first hundreds of meters to 10 km, as well as layered eolian-glacial deposits of polar caps. A special relief, "created by Aeolus", is confined to closed structures - the bottoms of large canyons and craters.

The morphological activity of the wind, which determines the peculiar features of the surface of Mars, manifested itself in intensive erosion (deflation), which led to the formation of characteristic "engraved" surfaces with cellular and linear structures.

Layered eolian-glacial formations, combined with ice mixed with sediments, cover the polar caps of the planet. Their power is estimated at several kilometers.

Geological characteristics of the surface

According to one of the existing hypotheses of the modern composition and geological structure of Mars, first an inner core of a small size was melted from the primary substance of the planet, consisting mainly of iron, nickel and sulfur. Then around the nucleus a homogeneous lithosphere with a thickness of about 1000 km was formed, in which, probably, even today active volcanic activity continues with the release of all new portions of magma to the surface. The thickness of the Martian crust is estimated at 50-100 km.

Since the man began to look at the brightest stars, scientists, as well as all those not indifferent to the universal neighbors, among other mysteries, were primarily interested in the surface of Mars.

Almost the entire planet is covered with a layer of brownish-yellowish-red dust with an admixture of fine aleurite and sandy material. The main components of the loose ground are silicates with a large admixture of iron oxides, giving the surface a reddish hue.

According to the results of numerous studies carried out by spacecraft, the fluctuations in the elemental composition of the loose deposits of the surface layer of the planet are not so significant as to suggest a great variety of the mineral composition of the rocks composing the Martian crust.

The average content of silicon (21%), iron (12.7%), magnesium (5%), calcium (4%), aluminum (3%), sulfur (3.1%), potassium and chlorine (<1%) indicated that the basis for loose deposits of the surface is the products of destruction of igneous and volcanogenic rocks of basic composition close to the basalts of the earth. Initially, scientists doubted the significant differentiation of the rocky shell of the planet in terms of mineral composition, but the Mars Exploration Rover (USA) studies of the base rocks of the Mars led to a sensational discovery of analogues of terrestrial andesites (medium-sized rocks).

This discovery, confirmed later by numerous finds of similar rocks, made it possible to judge that Mars, like Earth, can have a differentiated bark, which is evidenced by the substantial contents of aluminum, silicon and potassium.

Based on the huge number of images taken by spacecraft and allowing to judge what the surface of Mars is composed of, in addition to igneous and volcanic rocks, the planet obviously shows the presence of volcanic-sedimentary rocks and sedimentary deposits, which are recognized by the characteristic platy separation and stratification of fragments of outcrops.

The nature of stratification of rocks can indicate their formation in the seas and lakes. Areas of sedimentary rocks are fixed in many places of the planet and most often they are found in vast craters.

Scientists do not rule out the "dry" formation of sediments of their Martian dust with their further lithification (petrification).

Permafrost formations

A special place in the morphology of the surface of Mars is occupied by permafrost formations, most of which were manifested at different stages of the geological history of the planet as a result of tectonic shifts and the influence of exogenous factors.

Based on the study of a large number of space images, scientists unanimously concluded that in the formation of the image of Mars, along with volcanic activity, water plays a significant role. Volcanic eruptions led to the melting of the ice cover, which, in turn, served the development of water erosion, traces of which are still visible today.

The fact that the permafrost on Mars was formed already at the earliest stages of the geological history of the planet is evidenced not only by polar caps, but also by specific forms of relief similar to the landscape in permafrost zones on Earth.

Vortex formations, such as layered deposits in the polar regions of the planet, look like in the vicinity of a system of terraces, ledges and depressions, forming a wide variety of forms.

Deposits of polar caps several kilometers thick consist of layers of carbon dioxide and water ice, mixed with silty and fine silty material.

With the process of destruction of cryogenic strata, the failure-subsidence forms of relief associated with the equatorial zone of Mars are connected.

Water on Mars

On most of the surface of Mars, water can not exist in a liquid state due to low pressure, but in some district total area of about 30% of the planet's area, NASA experts allow the presence of liquid water.

The currently established water reserves on the Red Planet are concentrated mainly in the near-surface layer of permafrost (cryosphere) up to many hundreds of meters.

Scientists do not exclude the existence of relict lakes of liquid water and under the thickness of polar caps. Based on the estimated volume of the Mars cryolithosphere, water (ice) reserves are estimated at about 77 million km³, and if the probable volume of thawed rocks is taken into account, this figure may decrease to 54 million km³.

In addition, there is an opinion that under the cryolithosphere there may be beds with colossal saline water reserves.

A lot of facts indicate the presence of water on the surface of the planet in the past. The main witnesses are minerals, the formation of which implies the participation of water. First of all, it is hematite, clay minerals and sulphates.

Martian clouds

The total amount of water in the atmosphere of the "dried out" planet is more than 100 million times less than on the Earth, and yet the surface of Mars is covered with rare and unattractive, but real and even bluish clouds, though consisting of ice dust. Clouds form in a wide range of heights from 10 to 100 km and focus mainly in the equatorial belt, rarely rising above 30 km.

Ice fogs and clouds are also common near polar caps in winter (polar fog), but here they can "drop" below 10 km.

Clouds can be painted in a pale pinkish color, when the ice particles are mixed with dust raised from the surface.

Clouds of the most diverse forms are recorded, including wavy, striped and pinnate.

The Martian landscape from the height of human growth

For the first time, As the surface of Mars looks from the height of a tall man (2.1 m), the "arm" of the mars rover curiosity armed with a camera in 2012 allowed. Before the astonished look of the robot appeared "sandy", gravelly-gravelly plain, dotted with small cobblestones, with rare flat outcrops, possibly, indigenous, volcanic rocks.

A dreary and monotonous picture on one side was animated by a hilly ridge of the edge of the Gale crater, and on the other - the hollowed-out mass of Mount Sharpe, 5.5 km high, which was the object of hunting for the spacecraft.

Pointing the route along the bottom of the crater, the authors of the project apparently did not suspect that the surface of Mars, shot by the Curiosity rover, would be so diverse and heterogeneous, contrary to the expectation of seeing only a dull and monotonous desert.

On the way to Mount Sharp, the robot had to overcome fractured, flattened flat surfaces, gently sloping slopes of volcanic-sedimentary rocks (judging by the layered texture on the chips), and blocky disintegrations of dark bluish volcanics with a cellular surface.

The apparatus fired upon the "above-mentioned" targets (cobblestones) with laser pulses and drilled small holes (up to 7 cm in depth) to study the material composition of the samples. Analysis of the obtained material, in addition to the content of rock-forming elements characteristic of rocks of the basic composition (basalts), showed the presence of sulfur, nitrogen, carbon, chlorine, methane, hydrogen and phosphorus compounds, that is, "life components".

In addition, clay minerals formed in the presence of water with a neutral acidity index and a small concentration of salts were found.

On the basis of this information, together with the information previously received, scientists have tended to conclude that billions of years ago on the surface of Mars was liquid water, and the density of the atmosphere is much higher than today.

The morning star of Mars

Since in May 2003 the world flew a picture of the blue crescent of the Earth, made by the Mars Global Surveyor spacecraft from the orbit of the Red Planet at a distance of 139 million km, it seems to many that this is exactly what the Earth looks like from the surface of Mars.

But in fact, our planet looks from there approximately as we see Venus in the morning and evening hours, only a small dot shining slightly brighter than Venus, shining in the brownish blackness of the Martian sky (except for the weakly discernible Moon).

The first snapshot of the Earth from the surface was performed in the pre-dawn hour from the board of the Mars rover Spirit in March 2004, and the spacecraft Curiosity Earth "posed with the Moon" posed in 2012 and turned out even "more beautiful" than the first time.