Map of the Southern Plateau and the area in which research was carried out

The MARSIS probe of an area about 200 kilometers wide showed that the surface of the South Pole of Mars is covered with several layers of ice and dust and is about 1.5 kilometers deep. A particularly strong increase in signal reflection was recorded under layered sediments within a 20-kilometer zone at a depth of about 1.5 kilometers. After analyzing the properties of the reflected signal and studying the composition of the layered sediments, as well as the expected temperature profile below the surface of this area, the scientists concluded that MARSIS detected a pocket with a lake of liquid water below the surface. Scientists note that the device could not determine how deep the lake could be, but, according to rough estimates, its depth should be at least several tens of centimeters (this should be a layer of water for MARSIS to see it).

Image from MARSIS radar

“It really qualifies as a body of water. A lake, not some kind of meltwater filling some space between rock and ice, as happens in certain areas on Earth, ”commented Professor Roberto Orosei from the Italian Institute of Astrophysics, who led the study.

Theoretically, the increase in the signal that the lake is suspected of could produce a layer of frozen carbon dioxide or simply low-temperature water ice, but the authors reject these assumptions, as these options do not agree well with observational data.

“The only possible explanation for what we are seeing is liquid water,” Orosei said.

“With the help of MARSIS, we found out that there is liquid water there, it is salty and is in contact with bottom sediments. The ingredients for life to exist there are in place, and MARSIS cannot say anything more, it cannot answer the question of whether there is life there, ”added Enrico Flamini, representing the Italian Space Agency.

“Assumptions about the presence of liquid water under the polar caps of Mars appeared many years ago. However, so far they have not been able to confirm or refute them, just as it has not been possible to detect stable accumulations of liquid water on Mars, since the data collected were of very low quality, ”adds Andrea Cicchetti, co-author of the study.

Radar surveyed only a few percent of the Southern Plateau, and its characteristics allow you to see only fairly large accumulations of water.

“This is just one small area. Just imagine that there could be many such underground lakes of water under the surface of Mars.

Mars- the fourth planet of the solar system: map of Mars, interesting facts, satellites, size, mass, distance from the Sun, name, orbit, research with photos.

Mars is the fourth planet from the Sun and the most Earth-like in the solar system. We also know our neighbor by its second name - the Red Planet. It was named after the Roman god of war. The point is its red color, created by iron oxide. Every few years, the planet is closest to us and can be found in the night sky.

Its periodic appearance has led to the fact that the planet is displayed in many myths and legends. And the external menacing appearance became the cause of fear of the planet. Let's find out more interesting facts about Mars.

Interesting facts about the planet Mars

Mars and Earth are similar in surface massiveness

• The red planet covers only 15% of the earth's volume, but 2/3 of our planet is covered with water. Martian gravity is 37% of Earth's, which means your jump will be three times higher.

Possesses the highest mountain in the system

• Mount Olympus (the highest in the solar system) stretches for 21 km, and covers 600 km in diameter. It took billions of years to form, but the lava flows hint that the volcano may still be active.

Only 18 missions ended in success

• Approximately 40 space missions have been sent to Mars, including simple flybys, orbital probes and rover landings. Among the latter were the apparatus Curiosity (2012), MAVEN (2014) and the Indian Mangalyan (2014). Also in 2016, ExoMars and InSight arrived.

Major dust storms

• These weather disasters are capable of not calming down for months and cover the entire planet. The seasons become extreme due to the fact that the elliptical orbital path is extremely elongated. At the nearest point in the southern hemisphere, a short but hot summer sets in, and the northern one plunges into winter. Then they change places.

Martian debris on Earth

• The researchers were able to find small traces of the Martian atmosphere in the meteorites that arrived to us. They floated through space for millions of years before reaching us. This helped to conduct a preliminary study of the planet even before the launch of the devices.

The name came from the god of war in Rome

• In ancient Greece, they used the name Ares, who was responsible for all military operations. The Romans copied almost everything from the Greeks, so they used Mars as their counterpart. This trend was served by the bloody color of the object. For example, in China, the Red Planet was called the "fire star". Formed due to iron oxide.

There are hints of liquid water

• Scientists are convinced that for a long time the planet Mars had water in the form of ice deposits. The first signs are dark stripes or spots on the crater walls and rocks. Given the Martian atmosphere, the liquid must be salty so as not to freeze and evaporate.

Waiting for the ring

• In the next 20-40 million years, Phobos will come dangerously close and be torn apart by planetary gravity. Its fragments will form a ring around Mars that can last up to hundreds of millions of years.

Size, mass and orbit of the planet Mars

The equatorial radius of the planet Mars is 3396 km, and the polar radius is 3376 km (0.53 Earth). Before us is literally half the size of the earth, but the mass is 6.4185 x 10 23 kg (0.151 of the earth). The planet resembles ours in terms of axial tilt - 25.19 °, which means that seasonality can also be noted on it.

Physical characteristics of Mars

Equatorial	3396.2 km
Polar radius	3376.2 km
Medium radius	3389.5 km
Surface area	1.4437⋅10 8 km² 0.283 Earth
Volume	1.6318⋅10 11 km³ 0.151 Earth
Weight	6.4171⋅10 23 kg 0.107 terrestrial
Average density	3.933 g/cm³ 0.714 Earth
Acceleration free fall at the equator	3.711 m/s² 0.378g
first cosmic speed	3.55 km/s
Second space velocity	5.03 km/s
equatorial speed rotation	868.22 km/h
Rotation period	24 hours 37 minutes 22.663 seconds
Axis Tilt	25.1919°
right ascension north pole	317.681°
declination of the north pole	52.887°
Albedo	0.250 (Bond) 0.150 (geom.)
Apparent magnitude	−2.91m

The maximum distance from Mars to the Sun (aphelion) is 249.2 million km, and the proximity (perihelion) is 206.7 million km. This leads to the fact that the planet spends 1.88 years per orbital passage.

The composition and surface of the planet Mars

With a density of 3.93 g/cm3, Mars is inferior to Earth and has only 15% of our volume. We have already mentioned that the red color is due to the presence of iron oxide (rust). But due to the presence of other minerals, it is brown, golden, green, etc. Study the structure of Mars in the picture below.

Mars is a terrestrial planet, which means it has a high level of minerals containing oxygen, silicon and metals. The soil is slightly alkaline and has magnesium, potassium, sodium and chlorine.

In such conditions, the surface is not able to boast of water. But the thin layer of the Martian atmosphere allowed the preservation of ice in the polar regions. Yes, and you can see that these hats cover a decent territory. There is also a hypothesis about the presence of underground water at mid-latitudes.

The structure of Mars has a dense metallic core with a silicate mantle. It is represented by iron sulfide and is twice as rich in light elements as the terrestrial one. The crust extends for 50-125 km.

The core covers 1700-1850 km and is represented by iron, nickel and 16-17% sulfur. The small size and mass lead to the fact that gravity reaches only up to 37.6% of the earth. An object on the surface will fall with an acceleration of 3.711 m/s 2 .

It is worth noting that the Martian landscape is similar to the desert. The surface is dusty and dry. There are mountain ranges, plains and the largest sand dunes in the system. Mars also boasts the largest mountain - Olympus, and the deepest abyss - the Mariner Valley.

In the images, you can see many crater formations that have been preserved due to the slowness of erosion. Hellas Planitia is the largest crater on the planet, covering a width of 2300 km and a depth of 9 km.

The planet boasts ravines and channels through which water could previously flow. Some are 2000 km long and 100 km wide.

Moons of Mars

Two of its moons rotate near Mars: Phobos and Deimos. Asaph Hall found them in 1877 and named them after characters from Greek mythology. These are the sons of the god of war Ares: Phobos is fear, and Deimos is horror. Martian satellites are shown in the photo.

The diameter of Phobos is 22 km, and the distance is 9234.42 - 9517.58 km. It needs 7 hours for an orbital passage, and this time is gradually decreasing. Researchers believe that in 10-50 million years the satellite will crash into Mars or be destroyed by the planet's gravity and form a ring structure.

Deimos has a diameter of 12 km and rotates at a distance of 23455.5 - 23470.9 km. The orbital route takes 1.26 days. Mars may also have additional moons with a width of 50-100 m, and a dust ring can form between two large ones.

It is believed that previously the satellites of Mars were ordinary asteroids that succumbed to planetary gravity. But they have circular orbits, which is unusual for captured bodies. They may also have formed from material torn from the planet at the start of creation. But then their composition should have resembled a planetary one. A strong impact could also have occurred, repeating the scenario with our Moon.

Atmosphere and temperature of the planet Mars

The red planet has a thin atmospheric layer, which is represented by carbon dioxide (96%), argon (1.93%), nitrogen (1.89%) and oxygen impurities with water. It contains a lot of dust, the size of which reaches 1.5 micrometers. Pressure - 0.4-0.87 kPa.

The large distance from the Sun to the planet and the thin atmosphere have led to the fact that the temperature of Mars is low. It fluctuates between -46°C to -143°C in winter and can warm up to 35°C in summer at the poles and at noon on the equatorial line.

Mars is notable for the activity of dust storms that can mimic mini-tornadoes. They are formed due to solar heating, where warmer air currents rise and form storms that stretch for thousands of kilometers.

The analysis in the atmosphere also found traces of methane with a concentration of 30 parts per million. So, he was released from specific territories.

Studies show that the planet is capable of creating up to 270 tons of methane per year. It reaches the atmospheric layer and persists for 0.6-4 years until complete destruction. Even a small presence suggests that a gas source is hiding on the planet. The bottom figure indicates the concentration of methane on Mars.

Suggestions have hinted at volcanic activity, comet impacts, or the presence of microorganisms below the surface. Methane can also be created in a non-biological process - serpentinization. It contains water, carbon dioxide and the mineral olivine.

In 2012, some calculations were made on methane using the Curiosity rover. If the first analysis showed a certain amount of methane in the atmosphere, then the second showed 0. But in 2014, the rover encountered a 10-fold surge, which indicates a localized release.

Satellites also recorded the presence of ammonia, but its decomposition time is much shorter. A possible source is volcanic activity.

Dissipation of planetary atmospheres

Astrophysicist Valery Shematovich on the evolution of planetary atmospheres, exoplanetary systems and the loss of the Martian atmosphere:

History of the study of the planet Mars

Earthlings have long been watching the red neighbor, because the planet Mars can be found without the use of tools. The first records were made in Ancient Egypt in 1534 BC. e. They were already familiar with the retrograde effect back then. True, for them, Mars was a bizarre star, whose movement was different from the rest.

Even before the advent of the neo-Babylonian empire (539 BC), regular records of planetary positions were made. People noted changes in movement, brightness levels, and even tried to predict where they would go.

In the 4th century BC. Aristotle noticed that Mars hid behind the earth's satellite during the period of occlusion, and this indicated that the planet was located further than the moon.

Ptolemy decided to create a model of the entire universe in order to understand planetary motion. He suggested that there are spheres inside the planets that guarantee retrograde. It is known that the ancient Chinese knew about the planet as early as the 4th century BC. e. The diameter was estimated by Indian explorers in the 5th century BC. e.

The Ptolemaic model (geocentric system) created many problems, but it remained the main one until the 16th century, when Copernicus came along with his scheme with the Sun at the center (heliocentric system). His ideas were reinforced by Galileo Galilei's observations with a new telescope. All this helped to calculate the daily parallax of Mars and the distance to it.

In 1672, the first measurements were made by Giovanni Cassini, but his equipment was weak. Tycho Brahe used parallax in the 17th century, after which Johannes Kepler corrected it. The first map of Mars was presented by Christian Huygens.

In the 19th century, it was possible to increase the resolution of instruments and to consider the features of the Martian surface. Thanks to this, Giovanni Schiaparelli created the first detailed map of the Red Planet in 1877. It also displayed channels - long straight lines. Later they realized that it was just an optical illusion.

The map inspired Percival Lowell to create an observatory with two powerful telescopes (30 and 45 cm). He has written many articles and books on the subject of Mars. Channels and seasonal changes (reduction of the polar caps) prompted thoughts about the Martians. And even in the 1960s. continued to write studies on this topic.

Exploration of the planet Mars

More advanced exploration of Mars began with space exploration and launches to other solar planets in the system. Space probes began to be sent to the planet at the end of the 20th century. It was with their help that we managed to get acquainted with a strange world and expand our understanding of the planets. And although we have not been able to find the Martians, life could have existed there before.

Active study of the planet began in the 1960s. The USSR sent 9 unmanned probes that never made it to Mars. In 1964, NASA launched Mariner 3 and 4. The first failed, but the second flew to the planet 7 months later.

Mariner 4 managed to get the first large-scale images of an alien world and transmitted information about atmospheric pressure, the absence of a magnetic field and the radiation belt. Mariners 6 and 7 arrived on the planet in 1969.

In 1970, a new race began between the USA and the USSR: who will be the first to install a satellite in Martian orbit. Three vehicles were used in the USSR: Cosmos-419, Mars-2 and Mars-3. The first one failed at launch. The other two were launched in 1971 and took 7 months to get there. Mars 2 crashed, but Mars 3 landed softly and was the first to do so. But the transmission was only 14.5 seconds long.

In 1971, the United States sends Mariners 8 and 9. The first fell into the waters of the Atlantic Ocean, but the second successfully established itself in Martian orbit. Together with Mars 2 and 3, they fell into the period of the Martian storm. When it ended, Mariner 9 took several pictures hinting at liquid water that may have been observed in the past.

In 1973, four more vehicles departed from the USSR, where all but Mars-7 delivered useful information. The most useful was from Mars-5, which sent 60 images. The US Viking Mission started in 1975. These were two orbitals and two landers. They were supposed to track biosignals and study seismic, meteorological and magnetic characteristics.

The Viking survey showed that once there was water on Mars, because it was large-scale floods that could carve deep valleys and erode depressions in the rocks. Mars remained a mystery until the 1990s, when the Mars Pathfinder set off, represented by a spacecraft and a probe. The mission landed in 1987 and tested a huge amount of technology.

In 1999, the Mars Global Surveyor arrived, setting up surveillance of Mars in a nearly polar orbit. He studied the surface for almost two years. Managed to capture ravines and garbage streams. The sensors showed that the magnetic field is not created in the core, but is partially present in areas of the cortex. It was also possible to create the first 3D surveys of the polar cap. Contact was lost in 2006.

Mars Odysseus arrived in 2001. He had to use spectrometers to detect evidence of life. In 2002, huge hydrogen reserves were found. In 2003, the Mars Express arrived with a probe. Beagle 2 entered the atmosphere and confirmed the presence of water and carbon dioxide ice at the south pole.

In 2003, the famous Spirit and Opportunity rovers landed, which studied rocks and soil. MRO reached orbit in 2006. His instruments are set to search for water, ice, and minerals on/below the surface.

MRO surveys Martian weather and surface features daily to find the best landing sites. The Curiosity rover landed in Gale Crater in 2012. His instruments are important because they reveal the planet's past. In 2014, MAVEN began to study the atmosphere. In 2014, Mangalyan arrived from the Indian ISRO

In 2016, active study of the internal composition and early geological evolution began. In 2018, Roscosmos plans to send its apparatus, and in 2020 the United Arab Emirates will join.

Public and private space agencies are serious about creating crewed missions in the future. By 2030, NASA expects to send the first Martian astronauts.

In 2010, Barack Obama insisted on making Mars a priority target. ESA plans to send people in 2030-2035. There are a couple of non-profit organizations that are going to send small missions with a crew of up to 4 people. Moreover, they receive money from sponsors who dream of turning the trip into a live show.

SpaceX CEO Elon Musk launched global activities. He has already made an incredible breakthrough - a reusable launch system that saves time and money. The first flight to Mars is scheduled for 2022. We are talking about colonization.

Mars is considered the most studied alien planet in the solar system. Rovers and probes continue to explore its features, each time offering new information. It was possible to confirm that the Earth and the Red Planet converge in terms of characteristics: polar glaciers, seasonal fluctuations, atmospheric layer, flowing water. And there is evidence that earlier life could be located there. So we keep going back to Mars, which is likely to be the first planet to be colonized.

Scientists still haven't given up hope of finding life on Mars, even if it's primordial remains rather than living organisms. Thanks to telescopes and spacecraft, we always have the opportunity to admire Mars online. On the site you will find a lot of useful information, high-quality high-resolution photos of Mars and interesting facts about the planet. You can always use the 3D model of the solar system to track the appearance, characteristics and orbits of all known celestial bodies, including the Red Planet. Below is a detailed map of Mars.

Click on the image to enlarge it

Recently, an article was published in Science, which presented data from direct observations of ice layers under the surface of Mars at mid-latitudes. Especially for Attic, Vitaly "zelenyikot" Egorov tells a brief history of Martian water and what we have learned about it.

The presence of water on Mars has not been a secret for a long time. The reserves of water ice at the poles have already been roughly estimated, and glaciers have been discovered in the middle latitudes; it is known that even in the equatorial soil of the red planet, the concentration of water in places reaches a tenth. However, most data on the water content on Mars are obtained using radar or neutron spectrometers. And actually look at the Martian ice is rare. And just recently, such a meeting did happen: the HiRise orbital telescope aboard the Mars Reconnaissance Orbiter managed to photograph ice deposits on the slopes of ravines in mid-latitudes, and for the first time scientists were able to look at Martian glaciers in profile.

Astronomers examined the polar ice of Mars already in the 19th century - these are one of the most noticeable details of its surface. True, in previous centuries of astronomy, it was believed that the poles of the red planet were covered exclusively by frozen water. As long as optical means were of insufficient quality, many gaps in knowledge about the neighboring planet had to be closed by terrestrial analogies and optimistic expectations. It was from such expectations that the illusion of the Martian channels grew, which lasted until the very beginning of the space age. Astronomers could argue about the origin of the channels, artificial or natural, but most did not doubt their existence.

An end to the fate of the Martian channels was put by the NASA Mariner 4 probe, which in 1964 for the first time took pictures of sufficient quality of the planet's surface from close range. The landscapes that opened up to researchers destroyed all hopes for the “earthlikeness” of Mars. In 1973, the Soviet Mars-5 orbiter transmitted the first color images - these were photographs of a red, waterless and lifeless desert. In 1976, Viking 1 and 2 landers took soil samples and determined the water content in it - no more than 3%. By that time, it was already known that the seasonal variability of polar ice and the growth of polar caps in winter is determined not by water, but by "dry" carbon dioxide ice. And only white spots at the poles that do not change over the course of the year are the second layer of ice, already water.

The rediscovery of Martian water began in 2002 with the launch of NASA's Mars Odyssey satellite into operational orbit around planet four. An integral part of his GRS instrument was the Russian neutron spectrometer HEND. By recording the speed of neutrons escaping from the Martian soil under the impact of cosmic particles, HEND determined the concentration of hydrogen, which slows down neutrons. Hydrogen in free form cannot be contained in the soil of Mars, so its detection in the soil would suggest the presence of water or water ice there. By 2007, a complete map of the distribution of water in the near-surface layer up to 1 meter deep was built - unfortunately, one cannot look deeper using neutron spectroscopy. Even the data on the shallow distribution of water turned out to be unexpected for many - water was found.

The origin of these deposits is curious. An analysis of the nature of ice deposits in the polar caps led the researchers to the hypothesis that Mars repeatedly changed the inclination of its axis, deviating by 40 ° from the current 25 °. At some periods, the North Pole of Mars turned out to be turned directly towards the sun, which led to its active evaporation. The result was an increase in the density of the planet's atmosphere, dust storms and heavy snowfalls. Climatologists have applied the Earth's climate model to a similar scenario of Martian life and obtained data on heavy snowfall east of Hellas.

Finally, the result of direct observations of Martian ice deposits in the middle latitudes was recently published. A careful analysis of HiRise images allowed scientists to discover several cliffs, in the slopes of which white and bluish layers of ice are clearly visible.

An additional check with the CRISM hyperspectral instrument at the same MRO confirmed the presence of water. Observed ice deposits start at a depth of about 1 m and reach a thickness of 130 m. They alternate with layers of soil, apparently brought during seasonal dust storms. Most of the discovered ice slopes were found east of Hellas.

The study of these layers can reveal more about the climatic history of Mars. In addition, it is now clear that the future conquerors of the red planet will not have to extract water, following the example of the hero of the science fiction film "The Martian" - from rocket fuel. There will be enough buckets and shovels on the ground, and the water can be used just to produce fuel and return home. True, the middle latitudes are not the best place to land - it's too cold.

A series of images with a difference of three Martian years made it possible to see some changes in the appearance of the cliffs. Apparently, as in the case of polar glaciers, the melting processes continue, and the slopes slowly evolve.

What is even more interesting, all these frozen deposits did not originate billions of years ago, but quite recently by geological standards. If you take a broader look at the once snow-covered, but now covered with sand and dust expanses, you can be amazed at their virgin purity - there are almost no meteorite craters.

This means that the period of the stormy Martian atmosphere and planetary-scale snowstorms has ended quite recently. According to modern estimates, near-surface glacial deposits in the middle latitudes of Mars formed 10-20 million years ago - for the life of the planet, this is not even yesterday, but a minute ago.

It remains to be hoped that this will happen in the future - a dense atmosphere would greatly simplify the process of colonization.

In 2018, the European-Russian satellite ExoMars Trace Gas Orbiter will begin scientific work near Mars. On board is the FREND device, which operates on the HEND principle, but with a higher spatial resolution. It will not be able to see deeper than 1 meter into the ground, but it will be able to map surface ice deposits with much higher accuracy, which will allow us to study the water reserves on the red planet in more detail and plan future unmanned and manned missions even more accurately.

Vitaly Egorov

Composition of the atmosphere 95.72% ar. gas
0.01% Nitric oxide

Mars- the fourth largest planet from the Sun and the seventh largest planet in the solar system. This planet is 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(III) oxide.

Basic information

Due to the 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, ice water was discovered on Mars by NASA's Phoenix spacecraft. Phoenix) .

Currently (February 2009) the orbital research constellation in the orbit of Mars has three functioning spacecraft: " Mars Odyssey", " Mars Express" and " Mars Reconnaissance Orbiter", and this is more than around any other planet except Earth. The surface of Mars is currently being explored by two rovers: Spirit and Opportunity. There are also several inactive landers and rovers on the surface of Mars that have completed their missions. The geological data collected by all these missions suggests that a large part of the surface of Mars was previously covered with water. Observations over the past decade have revealed weak geyser activity in some places on the surface of Mars. Observations from the NASA spacecraft "Mars Global Surveyor", some parts of the south polar cap of Mars are gradually receding.

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 trapped in the gravitational field of Mars, like asteroid 5261 Eureka of the Trojan Group.

Mars can be seen from Earth with the naked eye. Its apparent stellar magnitude reaches −2.91 m (at the closest approach to the Earth), yielding in brightness only to Jupiter, Venus, the Moon and the Sun.

Orbital characteristics

The minimum distance from Mars to Earth is 55.75 million km, the maximum is about 401 million km. The average distance from Mars to the Sun is 228 million km. km (1.52 AU), the period of revolution around the Sun is 687 Earth days. The orbit of Mars has a rather noticeable eccentricity (0.0934), so the distance to the Sun varies from 206.6 to 249.2 million km. The orbital inclination of Mars is 1.85°.

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

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.

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 a snowfall, however, the snowflakes evaporated before reaching the surface.

According to researchers from the Carl Sagan Center, Mars is currently undergoing a warming process. Other experts believe that it is too early to draw such conclusions.

Surface

Description of the main regions

Topographic map of Mars

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 dust storms raging on Mars. This at one time served as an argument in favor of the fact 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 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. In the southern hemisphere, the surface is 1-2 km above the mean level and is heavily cratered. This part of Mars resembles the lunar continents. In the north, the surface is mostly below-average, with few craters, and the main part is occupied by relatively smooth plains, probably formed by 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 "froze" in this position. Another hypothesis involves the collision of Mars with a cosmic 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. years. Several types of craters can be distinguished: 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 last 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 basin (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 - Tarsis and Elysium. Tarsis is a vast volcanic plain 2000 km long, reaching a height of 10 km above the average level. There are three large shield volcanoes on it - Arsia, Pavonis (Peacock) and Askreus. On the edge of Tarsis is the highest mountain on Mars and in the solar system, Mount Olympus. Olympus reaches 27 km in height, 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 - Hecate, Elysium and Albor.

Channels of "rivers" and other features

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

Geology and internal structure

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

Phobos (top) and Deimos (bottom)

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/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 core of the Earth.

Moons 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 captured by the gravitational field of Mars, like 5261 Eureka from the Trojan group of asteroids.

Astronomy on Mars

This section is a translation of the English Wikipedia article

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.

Noon on Mars. Pathfinder image

Sunset on Mars. Pathfinder image

The color of the sky on Mars Earth and Moon Satellites - Phobos and Deimos

On the surface planets operate two rovers:

Planned missions

In culture

Books

• A. Bogdanov "Red Star"
• A. Kazantsev "Faetes"
• A. Shalimov "Price of immortality"
• V.Mikhailov "Special Necessity"
• V. Shitik "The Last Orbit"
• B. Lyapunov "We are on Mars"
• G.Martynov "Stargazers" trilogy
• G. Wells "War of the Worlds", the film of the same name in two adaptations
• Simmons, Dan "Hyperion", tetralogy
• Stanislav Lem "Ananke"

Films

• "Journey to Mars" USA, 1903
• "Journey to Mars" USA, 1910
• "Skyship" Denmark, 1917
• "Journey to Mars" Denmark, 1920
• "Journey to Mars" Italy, 1920
• "Ship sent to Mars" USA, 1921
• "Aelita" directed by Yakov Protazanov, USSR, 1924
• "Journey to Mars" USA, 1924
• "To Mars" USA, 1930
• "Flash Gordon: Mars Attacks the Earth" USA, 1938
• "Scrappy's Journey to Mars" USA, 1938
• "X-M Rocket" USA, 1950
• "Flight to Mars" USA, 1951
• "The sky is calling" directors A. Kozyr and M. Karyukov, USSR, 1959
• "Mars" documentary, director Pavel Klushantsev, USSR, 1968
• “First on Mars. The unsung song of Sergei Korolev, documentary, 2007
• "Martian Odyssey"

Other

• In a fictional universe

The maps were created from data obtained using the neutron spectrometer aboard the Mars Odyssey probe. The information collected over two Martian years allowed Institute senior scientist Thomas Prettyman and colleagues to pinpoint the seasonal variations in the thickness of the Martian ice caps.

In particular, it was possible to establish that about 25% of the atmosphere passes through these caps, Prettiman said. Already at the very beginning of telescopic observations of Mars, it was noticed that the polar caps on this planet change size and configuration depending on the season. It is now known that the caps are composed of water ice and frozen carbon dioxide - "dry ice". Water ice is believed to be a "permanent part" of the polar caps, and seasonal fluctuations are due to carbon dioxide.

The authors of the study note that the study of the polar caps will help to better understand the history of the planet's climate, and therefore answer the question of whether the conditions on Mars were once suitable for life. The thickness of the polar caps depends on several factors, in particular, on the solar energy absorbed by the surface and atmosphere at this point, as well as on the flow of warm air from low latitudes. In particular, near the north pole, carbon dioxide deposits are somewhat shifted towards the Acidalian Plain. Thicker deposits of carbon dioxide ice in this region may be due to cold winds blowing from a giant canyon near the north pole.

In the southern hemisphere, carbon dioxide accumulates more rapidly in the region of the so-called south polar residual cap, which contains perennial deposits of carbon dioxide ice. Scientists have concluded that the asymmetry of the south polar cap is associated with variations in the composition of the underlying soil. "The areas outside the residual cap are composed of water ice mixed with rock debris and ground that warms up in summer. This delays the onset of carbon dioxide ice accumulation in autumn. In addition, the heat stored in this water-rich region is gradually released in winter and autumn and limits carbon dioxide ice accumulation." ", says Prettyman.

He and his colleagues used neutron spectroscopy to also determine how much other gases - argon and nitrogen - remain in the atmosphere of the polar regions when carbon dioxide begins to "freeze out".

"We found a significant increase in the concentration of these gases in the South Pole region in autumn and winter," says Prettyman. According to him, variations in the concentration of these gases helped to gather information about local features of atmospheric circulation. In particular, large winter cyclones were found in the polar regions.

Accurate data on the thickness of carbon dioxide ice deposits, as well as data on seasonal fluctuations in the concentration of "non-freezing" gases, will allow scientists to refine the model of the Martian atmosphere, better understand its dynamics and figure out how the planet's climate changes over time.