The scheme of interaction of the field and the solar wind
There is no planetary magnetic field on the planet Mars. The planet has magnetic poles, which are remnants of an ancient planetary field. Since the magnetic field of Mars is virtually absent, it is constantly bombarded by solar radiation, as well as by the influence of the solar wind, which makes it the barren world that we see today.
Most planets create a magnetic field using the dynamo effect. The metals in the planet's core are molten and constantly moving. Moving metals create an electric current that eventually manifests itself as a magnetic field.
General information
Mars has a magnetic field, which is the remnants of ancient magnetic fields. It looks like the fields found at the bottom of the Earth's oceans. Scientists believe their presence is a possible sign that Mars had plate tectonics. But other evidence suggests that these plate movements stopped about 4 billion years ago.
The bands of the field are strong enough, much like that of the Earth, and can extend hundreds of kilometers into the atmosphere. They interact with the solar wind and create auroras just as they do on Earth. Scientists have observed over 13,000 of these auroras.
The absence of a planetary field means that its surface receives 2.5 times more radiation than the Earth. If humans are going to explore the planet, a way is needed to protect humans from harm.
One of the consequences of the absence of a magnetic field on the planet Mars is the impossibility of the presence of liquid water on the surface. The rovers have found large amounts of water ice beneath the surface, and scientists believe there may be liquid water there. Lack of water adds obstacles that engineers must overcome in order to study, and subsequently colonize, the Red Planet.
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Mars - the fourth planet of the solar system: a map of Mars, interesting facts, satellites, size, mass, distance from the Sun, name, orbit, research with a photo.
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 - "Red Planet". It received its name in honor of the god of war among the Romans. It's because of 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 led to the fact that the planet was reflected in many myths and legends. And the external threatening 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.
Has 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 lava flows hint that the volcano may still be active.
Only 18 missions ended in success
- Approximately 40 space missions were sent to Mars, including simple fly-overs, orbital probes and rover landings. The latter included the Curiosity apparatus (2012), MAVEN (2014) and Indian Mangalyan (2014). Also in 2016, ExoMars and InSight arrived.
Largest dust storms
- These weather disasters can last for months and cover the entire planet. The seasons get extreme because the elliptical orbital path is extremely elongated. At the nearest point in the southern hemisphere, a short but hot summer sets in, while the northern one plunges into winter. Then they change places.
Martian debris on Earth
- Researchers were able to find small traces of the Martian atmosphere in the meteorites that arrived to us. They swam in space for millions of years before reaching us. This helped to conduct a preliminary study of the planet even before the launch of the vehicles.
The name came from the god of war in Rome
- In ancient Greece, they used the name Ares, who was responsible for all military actions. The Romans copied almost everything from the Greeks, so they used Mars as their counterpart. The bloody color of the object served as such a trend. For example, in China, the Red Planet was called a "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 streaks or spots on crater walls and rocks. Given the Martian atmosphere, the liquid must be salty in order not to freeze and evaporate.
Waiting for the ring to appear
- In the next 20-40 million years, Phobos will come dangerously close and be torn apart by planetary gravity. Its debris 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 earth's size, but the mass is 6.4185 x 10 23 kg (0.151 of the earth's). The planet resembles ours in 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 |
| Average 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 earthly |
| Average density | 3.933 g / cm³ 0.714 earth |
| Speeding up free falls at the equator |
3.711 m / s² 0.378 g |
| First space speed | 3.55 km / s |
| Second space speed | 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 | −2.91 m |
The maximum distance from Mars to the Sun (aphelion) is 249.2 million km, and the approximation (perihelion) is 206.7 million km. This leads to the fact that the planet spends 1.88 years on an orbital passage.
The composition and surface of the planet Mars
With a density of 3.93 g / cm 3, Mars is inferior to Earth and has only 15% of our volume. We have already mentioned that the red color is formed due to the presence of iron oxide (rust). But due to the presence of other minerals, it is brown, gold, green, etc. Examine the structure of Mars in the picture below.
Mars belongs to the terrestrial planets, which means it has a high level of minerals containing oxygen, silicon and metals. The soil is slightly alkaline and contains 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 has kept ice in the polar regions. And you can see that these hats cover a decent area. There is also a hypothesis about the presence of groundwater at mid-latitudes.
The structure of Mars contains a dense metallic core with a silicate mantle. It is represented by iron sulphide and is twice as rich in light elements than earth. The crust stretches for 50-125 km.
The core covers 1700-1850 km and is represented by iron, nickel and 16-17% sulfur. Small size and mass lead to the fact that gravity reaches only 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 like a 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 2,300 km in width and 9 km in depth.
The planet is capable of boasting ravines and canals through which water could previously flow. Some are 2000 km long and 100 km wide.
Satellites of Mars
Near Mars, its two moons revolve: Phobos and Deimos. In 1877, they were found by Asaph Hall, who 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 forms a ring structure.
Deimos is 12 km in diameter and rotates at a distance of 23455.5 - 23470.9 km. The orbital route takes 1.26 days. Mars can also have additional moons with a width of 50-100 m, and a dust ring can form between the two large ones.
It is believed that earlier the satellites of Mars were ordinary asteroids that succumbed to planetary gravity. But they have circular orbits, which is unusual for captured bodies. They could also have formed from material ripped from the planet at the beginning of creation. But then their composition had to resemble the planetary one. A strong blow 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. There is a lot of dust in it, the size of which reaches 1.5 micrometers. Pressure - 0.4-0.87 kPa.
The long distance from the Sun to the planet and the thin atmosphere have led to the fact that the temperature of Mars is low. It jumps 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 distinguished by the activity of dust storms that can mimic mini-tornadoes. They are formed by solar heating, where warmer air currents rise and form storms that extend for thousands of kilometers.
When analyzed in the atmosphere, they also found traces of methane with a concentration of 30 parts per million. This means that he was liberated from specific territories.
Research shows that the planet is capable of producing 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.
Among the assumptions hinted at volcanic activity, the fall of comets or the presence of microorganisms under the surface. Methane can also be created in a non-biological process - serpentinization. It contains water, carbon dioxide and the mineral olivine.
In 2012, we carried out several methane calculations 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 burst, which indicates a localized release.
The 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 atmosphere of Mars:
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 neo-Babylonian empire (539 BC), planetary positions were regularly recorded. People noticed 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, which indicated that the planet was located farther than the Moon.
Ptolemy decided to create a model of the entire Universe to understand planetary motion. He suggested that there are spheres inside the planets, which guarantee retrograde. It is known that the ancient Chinese knew about the planet as early as the 4th century BC. e. Diameter was estimated by Indian explorers in the 5th century BC. e.
Ptolemy's model (geocentric system) posed many problems, but it remained dominant until the 16th century, when Copernicus came with his diagram of where the sun was in the center (heliocentric system). His ideas were supported by observations of Galileo Galilei 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. In the 17th century, Tycho Brahe used parallax, after which it was corrected by Johannes Kepler. The first map of Mars was presented by Christian Huygens.
In the 19th century, it was possible to increase the resolution of the instruments and consider the features of the Martian surface. Thanks to this, Giovanni Schiaparelli created the first detailed map of the Red Planet in 1877. Channels are also displayed on it - long straight lines. Later they realized that this 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 (shrinking polar caps) prompted thoughts about the Martians. Moreover, even in the 1960s. continued to write research on this topic.
Exploration of the planet Mars
More advanced exploration of Mars began with space exploration and the launch of spacecraft 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 the alien world and expand our understanding of the planets. And although we could not find the Martians, life may have existed there earlier.
An 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 after 7 months.
Mariner 4 was able to get the first large-scale images of an alien world and transmitted information about atmospheric pressure, the absence of a magnetic field and a radiation belt. In 1969, Mariners 6 and 7 arrived on the planet.
In 1970, a new race began between the USA and the USSR: who will be the first to install a satellite in Martian orbit. In the USSR, three vehicles were used: Cosmos-419, Mars-2 and Mars-3. The first one failed at startup. The other two started 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 lasted only 14.5 seconds.
In 1971, the United States sent Mariners 8 and 9. The first fell into the waters of the Atlantic Ocean, but the second was successfully entrenched in Martian orbit. Together with Mars 2 and 3, they fell into the period of the Martian storm. When it ended, Mariner 9 snapped several images hinting at liquid water that may have been seen in the past.
In 1973, four more vehicles were sent from the USSR, where all, except for Mars-7, delivered useful information. Most benefit was from Mars 5, which sent 60 images. The US Viking Mission was launched in 1975. These were two orbitals and two landing craft. They had to track biosignals and study seismic, meteorological and magnetic characteristics.
The Viking survey showed that there was once water on Mars, because it was large-scale floods that could carve deep valleys and wash out depressions in the rocks. Mars remained a mystery until the 1990s, when the Mars Pathfinder departed, represented by a spacecraft and probe. The mission landed in 1987 and tested a vast array of technologies.
In 1999, the Mars Global Surveyor arrived, tracking Mars in near-polar orbit. He studied the surface for almost two years. Managed to capture ravines and debris streams. The sensors showed that the magnetic field is not created in the nucleus, but is partially in areas of the cortex. We also managed to create the first 3D surveys of the polar cap. The connection was lost in 2006.
Mars Odysseus arrived in 2001. He had to use spectrometers to find 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 rovers Spirit and Opportunity were landed, which studied rocks and soil. MRO reached orbit in 2006. Its instruments are tuned to find water, ice and minerals at / below the surface.
MRO surveys Martian weather and surface characteristics daily to find the best landing sites. The Curiosity rover landed at Gale Crater in 2012. His tools are important as they reveal the planet's past. In 2014, MAVEN began to study the atmosphere. In 2014, Mangalyan flew in from the Indian ISRO
In 2016, an active study of the internal composition and early geological evolution began. In 2018, Roscosmos plans to send its device, and in 2020 the United Arab Emirates will connect.
Public and private space agencies are serious about creating crew missions in the future. NASA expects to send the first Martian astronauts by 2030.
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. And they receive money from sponsors who dream of turning the trip into a live show.
Global activity was launched by the CEO of SpaceX Elon Musk. 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 already talking about colonization.
Mars is considered the most studied alien planet in the solar system. Rovers and probes continue to explore its features, offering new information each time. It was possible to confirm that the Earth and the Red Planet converge on characteristics: polar glaciers, seasonal fluctuations, atmospheric layer, running water. And there is information that earlier life could be located there. Therefore, we continue to return to Mars, which will most likely become the first colonized planet.
Scientists have still not lost hope of finding life on Mars, even if these are primitive remains, not 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 photos of Mars in high resolution and interesting facts about the planet. You can always use a 3D model of the solar system to trace the appearance, characteristics and orbital motion of all known celestial bodies, including the Red Planet. Below is a detailed map of Mars.
Click on the image to enlarge it
The maps were created from data obtained using a neutron spectrometer aboard the Mars-Odyssey probe. The information gathered over two Martian years allowed the institute's senior researcher Thomas Prettyman and his 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, said Prettiman. Already at the very beginning of telescopic observations of Mars, it was noticed that the polar caps on this planet change in 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 study authors 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 the solar energy absorbed by the surface and the atmosphere at this point, as well as the flow of warm air from low latitudes. In particular, at the North Pole, carbon dioxide deposits are somewhat displaced towards the Acidali plain. The 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 faster in the area of \u200b\u200bthe so-called southern polar residual cap, which contains perennial deposits of carbon dioxide ice. The scientists concluded that the asymmetry of the south polar cap is related to variations in the composition of the underlying soil. “Areas outside the remnant cap are composed of water ice mixed with rock debris and soil that heats up in the summer. This delays the onset of carbonic ice accumulation in the fall. In addition, the heat stored in this water-rich region is gradually released in winter and autumn and limits the accumulation of carbonic ice ", - says Prettiman.
He and his colleagues used neutron spectroscopy to also determine how many other gases - argon and nitrogen - remain in the atmosphere of the polar regions when carbon dioxide begins to "freeze".
“We found a significant increase in the concentration of these gases around the South Pole in the fall and winter,” says Prettiman. Variations in the concentration of these gases helped to gather information about local atmospheric circulation patterns, he said. 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 atmosphere of Mars, better understand its dynamics and find out how the planet's climate changes over time.
The question of whether there is life on Mars has been haunting people for many decades. The mystery became even more relevant after suspicions arose about the presence of river valleys on the planet: if water flows once flowed through them, then the presence of life on the planet next to the Earth cannot be denied.
Mars, located between Earth and Jupiter, is the seventh largest planet in the solar system and fourth from the sun. The red planet is two times smaller than our Earth: its radius at the equator is almost 3.4 thousand km (the equatorial radius of Mars is twenty kilometers larger than the polar one).
From Jupiter, which is the fifth planet from the Sun, Mars is located at a distance of 486 to 612 million km. The Earth is much closer: the smallest distance between the planets is 56 million km, the greatest distance is about 400 million km.
It is not surprising that Mars is very clearly distinguishable in the earthly sky. Only Jupiter and Venus are brighter than it, and even then not always: once every fifteen to seventeen years, when the red planet approaches the Earth at a minimum distance, during the crescent, Mars is the brightest object in the sky.
They named the fourth in order planet of the solar system in honor of the god of war of ancient Rome, therefore the graphic symbol of Mars is a circle with an arrow that is directed to the right and up (the circle symbolizes vitality, the arrow is a shield and a spear).
Terrestrial planets
Mars, along with three more planets that are closest to the Sun, namely Mercury, Earth and Venus, are part of the terrestrial planets.
All four planets of this group are characterized by high density. Unlike gaseous planets (Jupiter, Uranus), they are composed of iron, silicon, oxygen, aluminum, magnesium and other heavy elements (for example, iron oxide gives a red tint to the surface of Mars). At the same time, the mass of the terrestrial planets is much inferior to the gas ones: the largest planet of the terrestrial group, Earth, is fourteen times lighter than the lightest gas planet in our system - Uranus.
Like the rest of the terrestrial planets, Earth, Venus, Mercury, Mars is characterized by the following structure:
- Inside the planet there is a partially liquid iron core with a radius of 1480 to 1800 km, with an insignificant admixture of sulfur;
- Silicate mantle;
- The crust, consisting of various rocks, mainly basalt (the average thickness of the Martian crust is 50 km, the maximum is 125).
It is worth noting that the third and fourth planets of the terrestrial group from the Sun have natural satellites. The Earth has one - the Moon, but Mars has two - Phobos and Deimos, which were named after the sons of the god Mars, but in the Greek interpretation, who always accompanied him in battle.
According to one of the hypotheses, the satellites are asteroids trapped in the gravitational field of Mars, so the satellites are small in size and have an irregular shape. At the same time, Phobos gradually slows down its movement, as a result of which in the future it will either disintegrate or fall on Mars, but the second satellite, Deimos, on the contrary, is gradually moving away from the red planet.
Another interesting fact about Phobos is that, unlike Deimos and other satellites of the planets of the solar system, it rises from the west side and goes beyond the horizon in the east.
Relief
In former times, the movement of lithospheric plates took place on Mars, which caused the rise and fall of the Martian crust (tectonic plates are moving now, but not so actively). The relief is notable for the fact that despite the fact that Mars is one of the smallest planets, many of the largest objects in the solar system are located here:
Here is the highest mountain found on the planets of the solar system - the inactive volcano Olympus: its height from the base is 21.2 km. If you look at the map, you can see that the mountain is surrounded by a huge number of small hills and ridges.
The largest system of canyons known as the Mariner Valley is located on the red planet: on the map of Mars, their length is about 4.5 thousand km, width - 200 km, depth - 11 km.
In the northern hemisphere of the planet is the largest impact crater: its diameter is about 10.5 thousand km, width - 8.5 thousand km.
Interesting fact: the surface of the southern and northern hemispheres is very different. On the south side, the relief of the planet is slightly raised and heavily strewn with craters.
In contrast, the surface of the northern hemisphere is below average. There are practically no craters on it, and therefore it is a smooth plain that was formed by spreading lava and erosion processes. Also in the northern hemisphere are the volcanic uplands, Elysium and Tarsis. The length of Tarsis on the map is about two thousand kilometers, and the average height of the mountain system is about ten kilometers (here is the Olympus volcano).
The difference in relief between the hemispheres is not a smooth transition, but represents a wide border along the entire circumference of the planet, which is located not along the equator, but thirty degrees from it, forming a slope in the northern direction (along this border there are the most eroded areas). At the moment, scientists explain this phenomenon for two reasons:
- At the early stage of the planet's formation, tectonic plates, being next to each other, converged in one hemisphere and froze;
- The border appeared after a planet collided with a space object the size of Pluto.
Poles of the red planet
If you look closely at the map of the planet of the god Mars, you can see that at both poles there are glaciers with an area of \u200b\u200bseveral thousand kilometers, consisting of water ice and frozen carbon dioxide, and their thickness ranges from one meter to four kilometers.
An interesting fact is that at the South Pole, the devices found active geysers: in the spring, when the air temperature rises, fountains of carbon dioxide soar above the surface, raising sand and dust
Depending on the season, the polar caps change their shape every year: in spring dry ice, bypassing the liquid phase, turns into steam, and the exposed surface begins to darken. In winter, the ice caps increase. Moreover, part of the territory, the area of \u200b\u200bwhich on the map is about a thousand kilometers, is constantly covered with ice.
Water
Until the middle of the last century, scientists believed that water could be found on Mars in a liquid state, and this gave reason to say that life on the red planet exists. This theory was based on the fact that light and dark areas were clearly visible on the planet, which very much resembled the seas and continents, and dark long lines on the map of the planet resembled river valleys.
But, after the very first flight to Mars, it became obvious that water, due to too low atmospheric pressure, cannot be in a liquid state on seventy percent of the planet. It is suggested that it did exist: this fact is evidenced by the found microscopic particles of the mineral hematite and other minerals, which are usually formed only in sedimentary rocks and clearly succumbed to the action of water.
Also, many scientists are convinced that the dark stripes on mountain heights are traces of the presence of liquid salt water at the present time: water flows appear at the end of summer and disappear at the beginning of winter.
The fact that this is water is evidenced by the fact that the stripes do not go over the obstacle, but rather flow around them, sometimes diverge and then merge again (they are very clearly visible on the map of the planet). Some features of the relief indicate that the river beds, during the gradual rise of the surface, shifted and continued to flow in a direction convenient for them.
Another interesting fact indicating the presence of water in the atmosphere is thick clouds, the appearance of which is associated with the fact that the uneven relief of the planet directs the air masses upward, where they cool, and the water vapor in them condenses into ice crystals.
Clouds appear over the canyons of the Mariner at an altitude of about 50 km when Mars is at the point of perihelion. Air currents moving from the east stretch the clouds for several hundred kilometers, at the same time their width is several tens.
Dark and light areas
Despite the absence of seas and oceans, the names assigned to the light and dark areas remained. If you look at the map, you will notice that the seas are mostly located in the southern hemisphere, they are well visible and well studied.
But what are the darkened areas on the map of Mars - this mystery has not yet been solved. Before the advent of spacecraft, it was believed that dark areas were covered with vegetation. Now it has become obvious that in places where there are dark stripes and spots, the surface consists of hills, mountains, craters, with collisions of which air masses blow out dust. Therefore, the change in the size and shape of the spots is associated with the movement of dust, which has light or dark light.
Priming
Another evidence that in earlier times life on Mars existed, according to many scientists, is the planet's soil, most of which consists of silica (25%), which, due to the iron content in it, gives the soil a reddish tint. The planet's soil contains a lot of calcium, magnesium, sulfur, sodium, aluminum. The acidity ratio of the soil and some of its other characteristics are so close to the terrestrial ones that plants could easily take root on them, therefore, theoretically, life in such a soil may well exist.
The presence of water ice was found in the soil (these facts were subsequently confirmed more than once). The mystery was finally solved in 2008, when one of the probes, staying at the North Pole, was able to extract water from the soil. Five years later, information was released that the amount of water in the surface layers of the soil of Mars is about 2%.
Climate
The red planet rotates on its axis at an angle of 25.29 degrees. Thanks to this, the sunny day here is 24 hours 39 minutes. 35 seconds, while the year on the planet of the god Mars due to the elongation of the orbit lasts 686.9 days.
The fourth-order planet in the solar system has seasons. True, summer weather in the northern hemisphere is cold: summer begins when the planet is as far away from the star as possible. But in the south it is hot and short: at this time Mars is as close as possible to the star.
Mars is characterized by cold weather. The average temperature of the planet is -50 ° C: in winter the temperature at the pole is -153 ° C, while at the equator in summer it is slightly more than +22 ° C.
An important role in the distribution of temperature on Mars is played by numerous dust storms that begin after the ice melts. At this time, atmospheric pressure rises rapidly, as a result of which large masses of gas begin to move towards the neighboring hemisphere at a speed of 10 to 100 m / s. At the same time, a huge amount of dust rises from the surface, which completely hides the relief (even the Olympus volcano is not visible).
Atmosphere
The thickness of the planet's atmospheric layer is 110 km, and almost 96% of it consists of carbon dioxide (oxygen is only 0.13%, nitrogen is slightly more: 2.7%) and is very rarefied: the pressure of the atmosphere of the red planet is 160 times less than near the Earth, while due to the large difference in altitude, it fluctuates strongly.
It is interesting that in winter, about 20-30% of the entire atmosphere of the planet is concentrated and freezes to the poles, and during the melting of ice it returns to the atmosphere, bypassing the liquid state.
The surface of Mars is very poorly protected from invading celestial objects and waves from outside. According to one of the hypotheses, after a collision with a large object at an early stage of its existence, the impact was of such force that the rotation of the core stopped, and the planet lost most of the atmosphere and magnetic field, which were a shield, protecting it from the invasion of celestial bodies and the solar wind, which carries with it radiation.
Therefore, when the Sun appears or recedes behind the horizon, the sky of Mars is reddish-pink, and a transition from blue to violet is noticeable near the solar disk. During the day, the sky turns yellow-orange, which is given to it by the reddish dust of the planet flying in the rarefied atmosphere.
At night, the brightest object in the sky of Mars is Venus, behind it is Jupiter with satellites, in third place is the Earth (since our planet is located closer to the Sun, for Mars it is internal, therefore it is visible only in the morning or evening).
Is there life on Mars
The question of the existence of life on the red planet became especially popular after the publication of the Wales novel "The War of the Worlds", according to the plot of which our planet was captured by humanoids, and earthlings only miraculously managed to survive. Since then, the secrets of the planet located between the Earth and Jupiter have been intriguing for more than one generation, and more and more people are interested in the description of Mars and its satellites.
If you look at the map of the solar system, it becomes obvious that Mars is at a short distance from us, therefore, if life could arise on Earth, then it could well appear on Mars.
The intrigue is also heated by scientists who report the presence of water on the planet of the terrestrial group, as well as conditions suitable for the development of life in the composition of the soil. In addition, pictures are often published on the Internet and specialized magazines, in which stones, shadows and other objects depicted on them are compared with buildings, monuments and even the remains of well-preserved representatives of the local flora and fauna, trying to prove the existence of life on this planet and unravel all the secrets Mars.
Map of the Southern Plateau and the study area
Sounding of an area about 200 kilometers wide with MARSIS 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 km zone at a depth of about 1.5 km. After analyzing the properties of the reflected signal and studying the composition of the layered deposits, as well as the expected temperature profile below the surface of this area, the scientists concluded that MARSIS found a pocket with a lake of liquid water below the surface. Scientists note that the device was unable to determine how deep the lake could be, but, according to rough estimates, its depth should be at least a few tens of centimeters (this should be the layer of water for MARSIS to see it).
Image from the MARSIS radar
“It really qualifies as a body of water. A lake, not some kind of melt water filling some space between rock and ice, as it happens in certain areas on Earth, ”commented Professor Roberto Orosei from the Italian Institute of Astrophysics, who is leading the study.
Theoretically, the amplification of the signal, in which the lake is suspected, can be provided by a layer of frozen carbon dioxide or simply water ice of low temperature, but the authors reject these assumptions, since these options do not agree well with observational data.
“The only possible explanation for what we see is liquid water,” Orosei said.
“With the help of MARSIS, we found out that there is liquid water, it is salty and in contact with bottom sediments. Ingredients so that life can exist there, in place, and more MARSIS can not say anything, he can not answer the question of whether there is life, ”- added Enrico Flamini, representing the Italian Space Agency.
“The assumptions about the presence of liquid water under the polar caps of Mars appeared many years ago. However, it has not yet been possible to confirm or deny them, just as it has not been possible to detect stable accumulations of liquid water on Mars, since the data collected was of very low quality, ”adds Andrea Cicchetti, co-author of the study.
Only a few percent of the southern plateau has been surveyed with the help of radar, and its characteristics only allow one to see large enough accumulations of water.
“This is just one small area. Just imagine that under the surface of Mars there can be many such underground lakes with water. "