Characteristics: The atmosphere of Mars is more rarefied than the air shell of the Earth. Its composition resembles the atmosphere of Venus and is 95% carbon dioxide. About 4% comes from nitrogen and argon. Oxygen and water vapor in the Martian atmosphere are less than 1% (see exact composition). The average atmospheric pressure at surface level is about 6.1 mbar. This is 15,000 times less than on Venus, and 160 times less than at the surface of the Earth. In the deepest depressions the pressure reaches 10 mbar.
The average temperature on Mars is significantly lower than on Earth - about -40° C. Under the most favorable conditions in summer, on the daytime half of the planet the air warms up to 20° C - a completely acceptable temperature for the inhabitants of the Earth. But on a winter night, frost can reach up to -125° C. At winter temperatures, even carbon dioxide freezes, turning into dry ice. Such sudden temperature changes are caused by the fact that the thin atmosphere of Mars is not able to retain heat for a long time. The first measurements of the temperature of Mars using a thermometer placed at the focus of a reflecting telescope were carried out back in the early 20s. Measurements by W. Lampland in 1922 gave an average surface temperature of Mars of -28°C; E. Pettit and S. Nicholson obtained -13°C in 1924. A lower value was obtained in 1960. W. Sinton and J. Strong: -43°C. Later, in the 50s and 60s. Numerous temperature measurements were accumulated and generalized at various points on the surface of Mars, in different seasons and times of day. From these measurements it followed that during the day at the equator the temperature could reach +27°C, but by the morning it could reach -50°C.
There are also temperature oases on Mars; in the areas of the Phoenix “lake” (solar plateau) and the land of Noah, the temperature difference ranges from -53° C to +22° C in summer and from -103° C to -43° C in winter. So, Mars is a very cold world, but the climate there is not much harsher than in Antarctica. When the first photographs from the surface of Mars taken by Viking were transmitted to Earth, scientists were very surprised to see that the Martian sky was not black, as expected, but pink. It turned out that dust hanging in the air absorbs 40% of the incoming sunlight, creating a color effect.
Dust storms: One of the manifestations of temperature differences is winds. Strong winds often blow over the surface of the planet, the speed of which reaches 100 m/s. Low gravity allows even thin air currents to raise huge clouds of dust. Sometimes quite large areas on Mars are covered in enormous dust storms. Most often they occur near the polar ice caps. A global dust storm on Mars prevented the Mariner 9 probe from photographing the surface. It raged from September 1971 to January 1972, raising about a billion tons of dust into the atmosphere at an altitude of more than 10 km. Dust storms most often occur during periods of great opposition, when summer in the southern hemisphere coincides with Mars' passage through perihelion. The duration of storms can reach 50-100 days. (Previously, the changing color of the surface was explained by the growth of Martian plants).
Dust Devils: Dust devils are another example of temperature-related processes on Mars. Such tornadoes are very common occurrences on Mars. They raise dust into the atmosphere and are caused by temperature differences. Reason: during the day, the surface of Mars warms up quite well (sometimes to positive temperatures), but at an altitude of up to 2 meters from the surface, the atmosphere remains just as cold. This difference causes instability, raising dust into the air - dust devils are formed.
Water vapor: There is very little water vapor in the Martian atmosphere, but at low pressure and temperature it is in a state close to saturation and often collects in clouds. Martian clouds are rather featureless compared to those on Earth. Only the largest of them are visible through a telescope, but observations from spacecraft have shown that clouds of a wide variety of shapes and types are found on Mars: cirrus, wavy, leeward (near large mountains and under the slopes of large craters, in places protected from the wind). There is often fog over lowlands - canyons, valleys - and at the bottom of craters during the cold season. In the winter of 1979, a thin layer of snow fell in the Viking 2 landing area, which remained for several months.
Seasons: Today it is known that of all the planets in the solar system, Mars is the most similar to Earth. It was formed approximately 4.5 billion years ago. Mars' rotation axis is inclined to its orbital plane by approximately 23.9°, which is comparable to the Earth's 23.4° axis tilt, and therefore, like on Earth, the seasons change there. Seasonal changes are most pronounced in the polar regions. In winter, the polar caps occupy a significant area. The boundary of the northern polar cap can move away from the pole by a third of the distance to the equator, and the boundary of the southern cap covers half of this distance. This difference is caused by the fact that in the northern hemisphere, winter occurs when Mars passes through the perihelion of its orbit, and in the southern hemisphere, when it passes through aphelion. Because of this, winter in the southern hemisphere is colder than in the northern hemisphere. And the length of each of the four Martian seasons varies depending on its distance from the Sun. Therefore, in the Martian northern hemisphere, winter is short and relatively “moderate”, and summer is long but cool. In the south, on the contrary, summers are short and relatively warm, and winters are long and cold.
With the onset of spring, the polar cap begins to “shrink,” leaving behind gradually disappearing islands of ice. At the same time, a so-called darkening wave is spreading from the poles to the equator. Modern theories explain it by the fact that spring winds transport large masses of soil with different reflective properties along the meridians.
Apparently none of the caps disappear completely. Before Mars was explored using interplanetary probes, it was assumed that its polar regions were covered with frozen water. More accurate modern ground-based and space measurements have also discovered frozen carbon dioxide in the Martian ice. In summer it evaporates and enters the atmosphere. The winds carry it to the opposite polar cap, where it freezes again. This cycle of carbon dioxide and the different sizes of the polar caps explain the variability in the pressure of the Martian atmosphere.
A Martian day, called a sol, is 24.6 hours long, and its year is sol 669.
Climate influence: The first attempts to find direct evidence in the Martian soil of the presence of the basis for life - liquid water and elements such as nitrogen and sulfur - were unsuccessful. An exobiological experiment conducted on Mars in 1976 after the American Viking interplanetary station, carrying an automatic biological laboratory (ABL), landed on its surface, did not bring evidence of the existence of life. The absence of organic molecules on the studied surface could be caused by intense ultraviolet radiation from the Sun, since Mars does not have a protective ozone layer, and the oxidizing composition of the soil. Therefore, the upper layer of the Martian surface (about a few centimeters thick) is barren, although there is an assumption that in the deeper, subsurface layers, conditions that existed billions of years ago have been preserved. A definite confirmation of these assumptions was the recently discovered microorganisms on Earth at a depth of 200 m - methanogens that feed on hydrogen and breathe carbon dioxide. A special experiment carried out by scientists proved that such microorganisms could survive in the harsh Martian conditions. The hypothesis of a warmer ancient Mars with open bodies of water - rivers, lakes, and maybe seas, as well as a denser atmosphere - has been discussed for more than two decades, since it would be possible to “inhabit” such an inhospitable planet, and even in the absence of water very difficult. In order for liquid water to exist on Mars, its atmosphere would have to be very different from the current one.
Changeable Martian climate Modern Mars is a very inhospitable world. A rarefied atmosphere, also unsuitable for breathing, terrible dust storms, lack of water and sharp temperature changes throughout the day and year - all this indicates that it will not be so easy to populate Mars. But rivers once flowed on it. Does this mean that Mars had a different climate in the past? |
Colonization involves settling Mars on a permanent basis, when people no longer live on shifts, but for a long time, have a permanent occupation and start families. Hypothetically, colonization can be carried out even with the achieved level of development of technology and technology. Although this is a fabulously expensive enterprise. Colonization requires not only technical ability, but a goal.
It is obvious that on Earth there are at least a hundred enthusiasts who are ready to live in extreme conditions on a distant planet. But such a colony will not last long. For truly serious colonization, you need a goal for which people will endure inconvenience and hardship on a very inhospitable planet, or a very serious reason.
For now, we can only guess what such a goal might become. The greed and greed of the conquistadors, the desire to rebuild and master everything, political interest, a necessary measure, escape from the realities and problems of earthly civilization - the list is large and not complete.
From a purely practical point of view, such a goal could be the development of mineral resources. Mars obviously had a different geological history than Earth. The amount of sedimentary rock on Mars is much less than on earth. The absence of free oxygen in large quantities allows us to expect deposits of native metals on Mars. It would be great if on Mars there were found elements that are rare on Earth (lutetium, europium, samarium, etc.). The discovery of rich deposits of uranium, the main raw material of extraterrestrial energy, will be very important for future colonization.
Another reason for the colonization of Mars may be unfavorable trends in the development of earthly civilization, which in the distant future will stimulate the search for alternative places of human habitation to Earth.
In other words, even a superficial analysis indicates that there are quite compelling reasons for the colonization of Mars. However, the future needs of the development of human civilization will also determine the degree of colonization of Mars. If the need for colonization of Mars is minimal, then everything can be limited to the study of Mars and the construction of temporary scientific bases. Three big needs: colonization can become so large-scale that the issue of terraforming Mars will be on the agenda of distant descendants in order to make the living of people on this planet more comfortable and safe.
A number of questions may arise here. Will there be a need in principle to terraform Mars? Maybe there is nothing interesting on Mars, and there will never be a special need for moving a large number of people there? Then it will be possible to get by with small colonies. After all, besides Mars, there are other planets and satellites where humanity can direct its efforts. Maybe it will be enough to build a couple of bases with an artificial habitat on Mars and not have to worry about rebuilding the entire planet?
Not all questions raised can now be answered comprehensively. Mars compares favorably with all other planets and satellites in two important circumstances.
1. Mars is close to the Earth, only the Moon is closer. When starting from Earth orbit, in order to reach the Moon, it is necessary to provide the ship with an increase in speedΔ V = 3.1 km/s, and to reach MarsΔ V = 3.6 km/s. As we see from an energy point of view, there is not much difference. Therefore, the cost of a kilogram of payload delivered to the Mars region and to the Moon region, although different, is insignificant. There is only a difference in flight time, which is not important for material assets.
2. Unlike the Moon and many satellites and planets, on Mars it is, in principle, possible to create a biosphere similar to the earth’s even with the current level of technological development, while transforming other celestial objects will require an order of magnitude greater effort. For example, on the Moon, the creation of a full-fledged atmosphere on the scale of the entire satellite is impossible even in the near future due to the lack of gaseous substances. On Mars, such an atmosphere already exists and it is only necessary to change its parameters; there are also deposits of frozen gases at the poles that can replenish the atmosphere.
Therefore, it is most realistic that it is on Mars in the distant future that our descendants will receive another vast territory on the surface of the planet sufficiently adapted for life to live in.
The surface area of Mars is 144 million km2, almost exactly equal to the land area on Earth! Even excluding the subpolar and high-mountain regions of Mars, and taking into account that part of the land in the future will be occupied by Martian seas, the area available for development on Mars will still be comparable to such continents as Eurasia or the Americas and Australia. For reference, America is 42 million km 2, Eurasia is 64 million km 2. Even if only half of the surface area of Mars is suitable for development, this will amount to at least 72 million km 2.
In other words, there is something to fight for. But first we need to answer the question. What are the physical conditions on Mars and is terraformation of Mars even possible?
2. Physical conditions on Mars
Mars is a planet where temperatures are below zero degrees most of the time. There is no liquid water, and there is little water vapor in the atmosphere. Otherwise, Mars is a very dry and cold planet with a thin atmosphere consisting of 95% carbon dioxide. In addition to CO 2, the atmosphere of Mars contains nitrogen (2.5%) and argon (1.5%). Oxygen - 0.1% water vapor - 0.2%. Large amounts of ice are concentrated at the poles. It’s just not completely known how many water people there are and how many dry people there are. The presence of permafrost is assumed. Thus, there are reserves of water on Mars, and there is also frozen carbon dioxide, which can fill the atmosphere and increase pressure.
The pressure corresponding to the conditional zero altitude on the surface of Mars is assumed to be 6 mbar (600 Pa) or 4.6 mm. Hg The maximum pressure in deep depressions is apparently of the order of 10 mbar.
Conditions on planet Earth are fundamentally related to the presence of a huge ocean of liquid water. Temperature on Earth is determined not only by the amount of heat coming from the Sun and the greenhouse effect, but is largely determined by the thermal regulation system of the hydrosphere and atmosphere. The evaporation and condensation of water equalizes the temperature and generally maintains conditions on the planet within a certain temperature range. Changing the amount of steam in the atmosphere in turn controls the greenhouse effect, but the steam collects in clouds that screen the flow of solar energy. Vast areas of snow-covered spaces in winter also participate in the general regulation. As a result, a complex self-regulating system operates on Earth.
On Mars, due to weaker gravity, much of the original atmosphere has long been lost. Hydrogen, helium and mostly nitrogen were lost as a result of the process of dissipation (escape) of molecules. Some of the water decomposed under the influence of ultraviolet radiation and was also lost. Because hydrogen, formed from the disintegration of water molecules, evaporated into outer space, and oxygen was bound by dust and rocks, in particular those containing iron, on the surface of the planet. Because of this, Mars has a blood red color. As a result of the loss of the primary atmosphere and the freezing of part of the atmospheric gases, the atmosphere became rarefied, the greenhouse effect weakened, and the hypothermia of the planet increased. As a result, part of the CO 2 and all the water froze, forming permafrost and polar ice caps.
However, seasonal phenomena occur on Mars, when the permafrost and polar ice caps partially melt. The regulation of pressure and density of the atmosphere is much less pronounced than on Earth and has a pronounced seasonal nature, which is associated with the melting of the polar caps. Another mechanism that controls conditions on Mars is powerful dust storms. During a dust storm, the surface of the planet becomes supercooled, but the atmosphere warms up somewhat.
The temperature on Mars changes like this. Around noon at the equator, dark objects heat up to +20 º C-+27º C, while the air remains cold. In the morning and evening the temperature is below zero, and at night in the morning it can reach -100 º C. The temperature contrast at the equator reaches 130 º C. In mid-latitudes, the temperature at night is approximately the same as at night at the equator, but during the day objects only heat up to 0 º C. Therefore, the temperature contrast is less. At the pole, the temperature can drop to -123 º WITH.
However, such a climate, if you do not take into account the nighttime temperature drop below -100C, is close to what we observe in Antarctica. The lowest temperature in Antarctica was recorded at Vostok station and amounted to -89.2 º C, and the average temperature at the Pole of Inaccessibility in Antarctica is -57.8 º C, which is close to the average temperature on Mars (-53 º C). Since people live and work in Antarctica, low temperatures are not an obstacle to the colonization of Mars. The main reason, as stated above, is low blood pressure.
Since above-zero temperatures on Mars are reached only near noon and near the equator, the existence of liquid water in deep depressions is rather a fantasy. Because it will inevitably freeze at night. Only a thin layer can thaw in a short period of time during the day. However, due to the evaporation of water and the sublimation of ice, this water will turn into steam and may ultimately end up at the pole of the planet. Phenomena similar to geysers on Earth on Mars are apparently not possible, since the thickness of the crust is about 100 km (on Earth 3-10 times less), and the presence of large underground reservoirs that could feed geysers can only be assumed hypothetically.
It can be assumed that in deep depressions of the crust, where the pressure is above the triple point of water, some moisture may fall in the form of dew. There are also clouds on Mars, although this is a fairly rare phenomenon compared to Earth. Only the largest clouds are visible through a telescope, but observations from spacecraft have shown that clouds of a wide variety of shapes and types are found on Mars: cirrus, wavy, leeward (near large mountains and under the slopes of large craters, in places protected from the wind). There is often fog over lowlands - canyons, valleys - and at the bottom of craters during the cold season. Due to the low pressure and temperature on Mars, water vapor is near saturation. So at a temperature of 0 º C the pressure of saturated water vapor is exactly 613 Pa, which corresponds to the pressure on Mars. In the winter of 1979, a thin layer of snow fell in the Viking 2 landing area, which remained for several months.
In winter, the polar caps occupy a significant area of the planet's hemisphere. The boundary of the northern polar cap can move away from the pole by a third of the distance to the equator, and the boundary of the southern cap covers half of this distance. This difference is caused by the fact that in the northern hemisphere, winter occurs when Mars passes through the perihelion of its orbit, and in the southern hemisphere, when it passes through aphelion. Because of this, winter in the southern hemisphere is colder than in the northern hemisphere. And the length of each of the four Martian seasons varies depending on its distance from the Sun. Therefore, in the Martian northern hemisphere, winter is short and relatively “moderate”, and summer is long but cool. In the southern hemisphere, on the contrary, summers are short and relatively warm, and winters are long and cold.
More accurate modern ground-based and space measurements have also discovered frozen carbon dioxide in the Martian ice. In summer it evaporates and enters the atmosphere. The winds carry it to the opposite polar cap, where it freezes again. This cycle of carbon dioxide and the different sizes of the polar caps explain the variability in the pressure of the Martian atmosphere.
Apparently in ancient times the pressure on Mars was higher, and water could exist in the form of open reservoirs, maybe even oceans. But as the atmosphere was lost, the greenhouse effect weakened and average temperatures on Mars moved below zero degrees. Then the process of freezing water, which was concentrated in giant refrigerators at the poles of the planet, became irreversible.
3. Mars colonies
It can be assumed that two types of colonies will exist on Mars at different times. Primary colonies before the terraformation of Mars and secondary colonies that will populate Mars during or after terraformation.
Colonies of the first type will obviously live under the surface of Mars or build structures from local materials that protect them from the external environment. Work outside artificial structures will be possible either in spacesuits or remotely from a sealed cabin of self-propelled or stationary mechanisms. Food products will have to be obtained from a greenhouse with an artificial atmosphere. This type of colony lives only within an artificially created habitat. The surface of the planet is used only for mining or other industrial or scientific activities. An important place in the activities of such a colony will be occupied by the production of food, oxygen, fuel, mining, construction and arrangement of underground structures, and geological exploration.
The population of the first type of colony will range from several dozen people to several hundred people. The number of colonies on Mars themselves will be determined by production needs. In fact, colonies of this type will be self-sufficient entities, living quasi-isolated from the rest of the Martian colonies.
To provide colonies on Earth, a new type of technology and production will appear - the development and creation of closed-type industrial and technological cycles focused on the use of Martian resources. For some reasons, some of the colonies will primarily be located in the low-lying parts of Mars near the equatorial zone. Mining will be developed directly next to the colony. Subsequently, these lowlands may become Martian seas. However, at the bottom of the seas, all the minerals will have already been mined by that time. True, in the long term the previously built colonies will have to be abandoned. Considering that hundreds or even thousands of years may pass before the lowlands are filled with water, this circumstance is unlikely to play any role.
After the stage of primary exploration and settlement of Mars, it will be possible to begin terraforming. This is a long stage and all this time colonies of the first type will exist on Mars.
4. Prospects terraformation
If the first stage of terraformation is carried out, then colonies of the second type may appear on Mars. Atmospheric pressure and surface temperature will become higher, and this will qualitatively change the world around us. Thicker clouds will appear in the sky, it will sometimes rain, it will snow more often, temporary ponds, streams, rivers and springs will appear.
As soon as special plants can grow in the external environment, specific “Martian” plants will be actively planted on Mars. At the beginning, these could be specific mosses or lichens that convert CO 2 from the atmosphere under the influence of sunlight into oxygen and organic substances, actively using the minerals of the Martian soil in this process. Over time, more complex types of organisms will appear that will populate entire spaces like alpine meadows or tundra fields.
On Earth, complex plants require insects, which means that special forms of Martian insects may appear. The density of the future Martian atmosphere may even allow such insects to fly. It is also possible that animals artificially created using genetic engineering methods will appear capable of living in the atmosphere of Mars. All this diversity of the biological world is necessary to create a full-fledged self-regulating biosphere.
The composition of the atmosphere will gradually begin to change. The carbon dioxide concentration will decrease, but more free oxygen will appear. Average temperature and pressure will increase. Open bodies of water, possibly seas and oceans, will appear on the surface of Mars. People will be able to work on the surface without sealed spacesuits, but they will have to use special breathing devices, like scuba divers. During this period, a planet-wide biosphere will be created on Mars.
Finally, the third stage has begun, when Mars will turn into the younger “brother” of the Earth. People will be able to live on the surface without any breathing devices. The atmospheric density will be the same as on the plateaus of Mexico in the mountains of Peru or the Himalayas. And the surrounding landscapes will be much like high mountain conditions on Earth. In contrast to the highlands of the Earth, alpine meadows with tall grasses will grow on Mars, resistant to winds at higher elevations, and in the lowlands there will be tall trees because there is less gravity on Mars. However, this stage is still very, very far away.
Considering all of the above, one can expect that, based on the highest interests of the development of earthly civilization, the United Nations can begin the process terraforming planet Mars after the completion of the first stage of its exploration.
Successful terraformation of Mars requires solving a number of complex problems. The first and most important problem. The pressure on Mars is currently too low. The average pressure on the surface of Mars is assumed to be 6 mbar (600 Pa) or 4.6 mm. Hg The maximum pressure in deep depressions is apparently of the order of 10 mbar. This pressure is too low for the existence of terrestrial life forms.
5. Why increase the pressure on Mars?
The reasons for high blood pressure are very significant. At such low pressure, which now exists on Mars, water cannot exist in a liquid state. This means that Earth-type life, based on an aqueous solution of biologically active substances in cells, cannot exist on Mars. The water in the cells will simply boil. Of course, it is possible to create forms of living things that can live in such conditions, but there are other reasons. Therefore, the first task of terraformation is to achieve a pressure at which water, without boiling, will be on the surface of Mars in a liquid state.
Another important reason is the need to create the most comfortable living conditions for a person. The thin atmosphere on Mars creates more problems than the vacuum on the Moon. First of all, this is due to the abundance of dust and the greater opportunity for dust to be transferred and end up where it is not necessary in a rarefied atmosphere. Dust will damage mechanisms, spacesuits, etc. If the pressure on Mars increases, it will be possible to plant plants that will bind dust, precipitation will fall, and moisture will remain in the soil (in summer) or snow will lie (in winter), which will limit dust effects. The presence of moisture will cause the soil to compact and the thin, thin surface layer will blow away. With a higher density of the atmosphere, the dust storms themselves will weaken.
In addition, more greenhouse gases will raise the average temperature, making it warmer, which is important for industrial activity and survival. Higher atmospheric density will reduce heat transfer from the surface at night and increase night temperatures, and reduce the overall temperature difference. The high density of the atmosphere will weaken the level of radioactive radiation on the surface of the planet and the level of ultraviolet radiation.
Finally there is one more reason. It is related to the survival of people in emergency situations. The emergency situation is primarily associated with depressurization of spacesuits or living spaces. At the current low pressure, people have from several seconds to several minutes to eliminate the accident. All this cannot but restrain colonization. Therefore, the first goal of terraformation should be to create conditions where a person can live on Mars without a spacesuit, only with a breathing device, or even as a distant final goal to create conditions for breathing Martian air.
6. Limits of life
Earth-type living things can only exist within certain ranges of physical parameters.
“Conditions of suitability for the habitat of flora and fauna” according to McKay
|
Parameter |
Meaning |
Explanation |
||
|
average temperature |
0 - 30 °C |
The average surface temperature should be about 15 °C |
||
|
Flora |
||||
|
Average atmospheric pressure |
> 10 kPa, (>75Hg) |
The main components of the atmosphere should be be: water vapor, O 2, N 2, CO 2 |
||
|
O2 partial pressure |
> 0.1 kPa, (>0.75Hg) |
Plant respiration |
||
|
CO2 partial pressure |
> 15 Pa, (>0.1 Hg) |
Lower limit for flow condition photosynthesis reactions; no clear upper limit |
||
|
Partial pressure N 2 |
> 0.1-1 kPa, (>0.7 - 7.7Hg) |
Nitrogen fixation |
||
|
Steam ( t= 15 °C) |
<1 .7 кПа (< 12.8 Hg ) |
Saturating vapor pressure of H 2 O at 15°C. |
||
|
Minimal atmosphere |
0.75О 2 +0.1СО 2 +0.7 N 2 +12 H 2 O + 62buffer = 75(Hg) 1% O2 + 1% N 2 + 0.1% CO 2 + 16% H 2 O + 82% buffer |
|||
|
Carbon freeatmosphere of Mars |
60% N 2 + 36% Ar+ 2% O 2 + 2% (rest) |
|||
|
Fauna |
||||
|
Average atmospheric pressure |
> 5 kPa, (>37.6Hg) < 500 кПа , (<5 at.) |
The minimum and maximum are indicated pressure |
||
|
O2 partial pressure |
> 25 kPa, (>188Hg) |
|||
|
CO2 partial pressure |
< 10 кПа , (<75Hg) |
Limiting CO 2 content to avoid intoxication |
||
|
Partial pressure N 2 |
> 30 kPa, (>225 Hg) |
Buffer |
||
Line 6 gives the pressure increase that water vapor will give at a temperature of 15ºC in a closed room. Line 7 shows the composition of the minimum atmosphere that is suitable for breathing by plants. Nitrogen, argon or methane can be used as a buffer.
As can be seen from the table above, plants require a pressure above 75 mm. rt . Art., for animals above 37.6 mm. rt . Art. (the lower limit beyond which death occurs). But animals need significantly higher oxygen pressure to breathe. Plants require an oxygen pressure above 0.75 mm Hg. Art., whereas for animals over 188 mm. rt . Art.
If we consider the atmosphere necessary only for plants (line 7), then it turns out that it is not difficult to obtain such a composition. It is enough to remove CO 2 from the current atmosphere of Mars and compress the required volume of the resulting gas to the required pressure of 75 mm. Hg As a result, such Martian air will consist of 96% nitrogen and argon and will contain 2% oxygen. It is necessary to add at least 0.01% CO 2 to such air and heat it to 15ºC, and the partial pressure of water vapor will establish itself depending on the irrigation mode. This is how it turns out " carbon-free» an atmosphere that is quite suitable for plants in greenhouses.
For pets and people need to be enriched carbon-free Martian air with oxygen. Up to a partial pressure of at least 188 mm. Hg At the same time, it is necessary to increase the partial pressure of nitrogen and argon in order to bring the ratio of oxygen and buffer gases approximately to the ratio in the earth’s atmosphere. Plants or algae such as chlorella can handle the task of saturating the air with oxygen. In the future, it is possible to close the artificial biosphere. It is only necessary to accurately maintain the proportion between the number of animals and plant biomass. But all this is possible only in enclosed spaces or in the conditions of the existence of colonies of the first type.
7. Surviving low blood pressure
For colonists, the problem of depressurization of premises and, first of all, spacesuits will be urgent. When depressurizing under conditions of low external pressure, the main danger is associated with shock decompression in the event of serious damage to the suit. When breathing pure oxygen inside the spacesuit, the pressure will not be lower than 188 mm Hg. And in the case of breathing a gas mixture it is even higher.
Decompression experiments were carried out on animals. This is how astronaut Mitchell describes them. “Within 1 second, the pressure in the pressure chamber where the animals were located was lowered from 180 mm Hg to less than 2 mm Hg. At such a low pressure, dogs remained for 5-10 seconds, and chimpanzees for up to 150 seconds. Both dogs and chimpanzees fell into a state of shock 9-12 seconds after the start of decompression. At this moment, “bloating” of their bodies, convulsions, difficulty breathing and a general spastic state of the muscles could be observed. 120-180 sec. death occurred, then in all chimpanzees after decompression the normal state was restored without any consequences for the nervous system. After recompression (increasing the pressure to normal), they began to breathe spontaneously. the vascular system was still functioning well enough to restore normal blood pressure.
Several chimpanzees were subjected to decompression in an atmosphere of pure oxygen, the pressure in the pressure chamber was reduced over 0.8 seconds from 179 to 2 mm Hg, the animals were maintained at this low pressure for 210 seconds. After recompression, which was carried out gradually, the chimpanzees recovered and were able to perform the complex tasks for which they had previously been trained. Repeated experiments invariably gave the same results. This suggests that humans are also able to withstand extremely low pressures better than we think. It is likely that an astronaut outside the spacecraft could be saved if his suit were suddenly damaged and the air or oxygen pressure in it began to drop sharply due to a leak.”
On Mars the pressure is now 4.6 mmHg. This is twice as much as in the experiments described, but it is still not enough. With a sharp drop in pressure in a spacesuit, a person on Mars has only 10 - 15 seconds left. Until loss of consciousness. However, timely assistance provided by comrades within 1 - 3 minutes can save a person. This requires rapid recompression to a pressure of at least 200 mm Hg.
In conditions of low pressure or vacuum, hypoxia initially occurs, associated with a lack of oxygen and a person in 10 s. loses consciousness. A diver underwater uses the oxygen supply in his lungs, but here there is no such opportunity. Since a person in a vacuum must exhale air from the lungs to prevent rupture of internal tissues.
The next dangerous process is associated with the boiling of fluids, primarily blood, and blood flow practically stops. Heart fibrillation occurs and the person may already die from cardiac arrest at this moment. After cardiac arrest, resuscitation is almost impossible, since cardiac arrest occurs due to irreversible measurements in the circulatory system. Due to the release of gases in the internal organs, the body swells. This swelling can be partially compensated for by a special suit; it is used by pilots of stratospheric aircraft. However, the pilot at an altitude of 15 km has only 10 s. to make a decision to sharply reduce altitude.
In one of the flights, when the glove depressurized at an altitude of 12 km, the tester, who was ascending in a balloon, reached an altitude of 30 km (10 mm Hg). His arm swelled to twice its normal size, but he was able to complete the experiment successfully, and after returning to earth, the arm returned to normal within a few hours. The fact is that the vessels and capillaries have flexibility, which compensates for the drop in external pressure.
During the Shuttle flight STS -37 there was damage to the gloves of one of the astronauts. However, the pressure of the suit and the compaction due to the pressing of the palm against the damaged area did not lead to explosive decompression. The astronaut, being in a state of excitement from going into outer space, did not even notice that his glove was punctured. He escaped with a minor scratch.
Therefore, in the event of a spacesuit accident, the main threat is that a person cannot breathe due to an air leak, the brain is no longer supplied with oxygen, and not from low pressure. In order to avoid tissue rupture in the lungs, a person during an accident in Mars conditions associated with explosive decompression must exhale as much air as possible and hold his breath with empty lungs. It will be difficult to do for a long time, since instinctively a person will be overcome by the desire to inhale. But breathing the air of Mars is dangerous. Excess carbon dioxide can lead to poisoning of the body. Although it will probably not be possible to inhale any significant amount of carbon dioxide from the rarefied atmosphere. The person will lose consciousness before the atmosphere of Mars fills the damaged spacesuit. Stopping breathing will prevent further penetration of Martian air into the victim’s body.
Therefore, in the presence of external pressure of several tens of mm. Hg all these problems will be significantly weakened. In this case, to compensate for the drop in pressure and swelling of the circulatory system, you can use a special compensating suit, similar to those used in high-altitude aviation. The presence of a compensating suit and an oxygen mask will make it possible for a person to survive even with a damaged spacesuit. Here, hypothermia or CO 2 poisoning can pose a great danger if there is a poor fit of the mask to the face and gas leaks from the outside. In this case, we are no longer talking about seconds before a fatal outcome, which will make many accidents less dangerous.
8. Possibility and scale of atmospheric reconstruction
How much do you need to increase the pressure on Mars so that a person can do without a spacesuit?
There are two options here.
1. Breathing through an oxygen mask.
2. Direct breathing of Martian air.
The following factor can be taken as a criterion. Fluids in the body are at a temperature of 37 º C. Boiling water at a temperature of 40 º C corresponds to a pressure of 55 mm Hg, which on Earth corresponds to an altitude of 18 km. Thus, the ambient pressure in any case should not be lower than 55 mm Hg.
Two cases must be distinguished. The case of being in the Martian atmosphere, outside living quarters without a spacesuit, and the case of being in greenhouses and utility rooms where the atmosphere differs from the standard one. These cases differ only in the composition of the atmosphere, since in special rooms it will be artificial.
Staying at low blood pressure involves movement and work, not just survival. As climbers reach the summit, hard work is done. The highest altitude at which people have actively worked on Earth corresponds to an altitude of 8.8 km (Everest). Climbers at this altitude can do without an oxygen mask, but hard work and prolonged stay at such an altitude requires the use of an oxygen mask. You can survive at such a height only by making a minimum of movements. Thus, a person can live at a pressure corresponding to an altitude of about 9 km. At this altitude, the air pressure is only 230 mmHg. or 3 times less than on the plain. Apparently the oxygen content is a little more than three times less. Let's assume the partial pressure of oxygen at an altitude of 9 km is 55 mm Hg.
So, if the atmosphere of Mars consisted of pure oxygen, a pressure of 55 mmHg would be enough. At this pressure, water no longer boils at the temperature of the human body and there should be enough oxygen to simply maintain vital functions. However, the minimum pressure of pure oxygen is about 180 mmHg. Art. A pure oxygen atmosphere on Mars can only be created in a closed volume of a living space or spacesuit.
As shown above, for greenhouses it will be enough to create an artificial atmosphere with a pressure of 75 mm or more. Hg and a minimum CO 2 content, which will allow you to work in such conditions without a spacesuit, but only with an oxygen mask. It is clear that this is the minimum requirement for plant life.
Creating large areas of greenhouses, or better called greenhouses, will require large volumes of capital construction. Since the size of the colony is related to the total required area of the greenhouse (greenhouse), and this determines the volume of construction work, which in turn is related to the composition of the atmosphere and internal pressure. This is discussed in more detail in the section on construction on Mars. Therefore, the composition of the atmosphere and the pressure in non-residential premises will not necessarily be the same as in residential premises.
Suppose, with the help of plants, it will be possible to raise the oxygen content in the atmosphere of Mars to a partial pressure exceeding 55 mm Hg. It is obvious that the atmosphere cannot consist of pure oxygen, even at low pressure. A high concentration of oxygen is not only dangerous, it is also impossible, since oxygen will inevitably bind as a result of chemical reactions. To limit this process, a buffer gas is needed. Nitrogen plays the role of such a buffer gas on Earth. Under Mars conditions, such a buffer gas could be nitrogen and argon. The atmosphere may also contain methane in small quantities as a buffer gas.
Create a partial pressure of oxygen in the atmosphere of Mars above 55 mmHg. Art. this is only one part of the terraforming task. Another problem is the presence of CO 2. It is known that exceeding 4% CO 2 in the air leads to poisoning of people and animals. Therefore, ideally, CO 2 in the atmosphere of Mars should not exceed 4%. Therefore, the main problem of the final stage of terraformation is not even the problem of creating an oxygen atmosphere, but the problem of binding excess carbon dioxide and filling the atmosphere with a buffer gas instead of carbon dioxide.
Currently, the atmosphere of Mars contains 95% CO 2, but even if oxygen is isolated from all carbon dioxide, it will be small, only 3 mm Hg, and at least >55 mm Hg is required. Therefore, to ensure a minimum oxygen content, it is necessary to extract more than ten times the volume of gases from the polar caps, liberate them from oxides, or deliver them from outside compared to what is currently in the atmosphere of Mars. Then this gas containing a lot of CO 2 needs to be processed and purified. This is already work for plants, designed to last hundreds of years.
But this is not enough. We need to get a buffer gas somewhere, since there are very few reserves of nitrogen or argon on Mars.
On Earth, large volumes of CO 2 from the atmosphere are dissolved by the ocean. For Mars this path is not effective. There are already so few gases. The dissolution of CO 2 in the Martian ocean will only lead to a decrease in overall pressure. A decrease in pressure and CO 2 content will lead to a decrease in the greenhouse effect, and a new ice age will begin. Everything will freeze again. True, algae can convert CO 2 dissolved in water bodies into oxygen, as they do on Earth. The presence of water vapor in the atmosphere will support the greenhouse effect, but more vapor will appear in the atmosphere only if the average temperature is higher. It turns out to be a vicious circle or otherwise a self-regulating system.
Summarizing the results, we can draw conclusions. On Mars, it is theoretically possible to create conditions for the life of terrestrial plants, and possibly some insects. To do this, it is necessary to increase the pressure to 75 mm. Hg (about 15 times) and the temperature is slightly above zero. Such pressure will allow a person in a special suit and an oxygen mask to stay on Mars for some time, and possibly for a long time, without a spacesuit. On Earth, this pressure corresponds to an altitude of 16 km.
However, this is possible with sufficiently large reserves of frozen carbon dioxide, which must be evaporated as a result of technogenic activity. If there is not enough carbon dioxide, then gases will have to be delivered to Mars from outside, which will make terraformation a very long and very difficult task.
An alternative is the creation of specific plants or microorganisms capable of surviving in Martian conditions and capable of gradually transforming the atmosphere and soil in the direction necessary for further terraformation.
It is clear that when delivering the necessary masses of gases to Mars, it is possible to create an atmosphere of any composition, but this is truly a titanic task.
Let us roughly estimate the minimum required for the survival of people without breathing equipment on the surface of Mars. Let the partial pressure of oxygen be at least 55 mmHg. The buffer gas pressure is two to three times greater or 150 mm. Hg Let it be a mixture of nitrogen, argon and possibly methane.
In total, the pressure of such an atmosphere is approximately 200 mm Hg, which is very close to the pressure on Everest. All carbon dioxide was bound by plants and the residual concentration of CO 2 should not be more than 1-2%.
Approximate composition: 25% - O 2, 30% - nitrogen, 40% - argon, 2% - methane and 2% - CO 2. You can probably breathe this kind of air. The ratio of buffer gases may be different.
Now the total volume of gases in the atmosphere of Mars provides a pressure of 4.6 mm Hg. or almost 40 times less. Otherwise, to create an atmosphere suitable for survival (not habitation!) on Mars, approximately 40 volumes of the current atmosphere must be evaporated from the polar caps or brought from outside. The estimate is rough because pressure depends on temperature and at higher temperatures the required volume will be less. Approximately 30 volumes.
However, the volumes are huge. Therefore, the complete terraformation of Mars is a matter of the very, very distant future.
More realistic is only an increase in pressure and temperature above the critical pressure corresponding to the triple point of water.
9. The role of water in regulating the climate on Mars
In general, the relationship between the state of water and conditions on the terrestrial planets is illustrated by the diagram of the state of water given here. Let me remind you that since water can exist in three phases (ice, water, steam), and the melting and boiling points of water depend on pressure, the graph of the state of water looks like a two-horned curve. At temperatures below 0 º C(left side of the graph) water is in the form of ice or steam. When the temperature is above 0 º C(right side of the graph) water is either liquid or vapor. Only at a pressure above 610 pa (4.58 mm Hg) can water exist in liquid form. Therefore, the point where water can simultaneously exist and in all three phases has coordinates ( R= 610.6 Pa;t= +0.01С).
On the graph, bold lines, orange - Mars, blue - Earth, for Venus, a red square indicates the current conditions on the terrestrial planets. The rectangle below the line shows the range of pressures and temperatures taking into account the planet's topography. There are taller mountains on Mars, and the depressions on Earth are filled with ocean, so the heights of the rectangles are different. On Venus, conditions depend little on altitude and latitude on the planet, so they are represented by a small square. The final post-terraformation states for Venus and Mars are shown by arrows.
The coincidence of the orange stripe with the bottom side of the rectangle just means that at the end of terraformation, the conditions on Mars should correspond to the conditions on Earth high in the mountains. On Venus, the temperature and pressure will most likely be higher than on Earth, so the final state is shown above.
10. Mars atmospheric engineering
For Venus, it is necessary to reduce the pressure and, accordingly, the density of the atmosphere, which can only be done in one way - to remove most of the atmospheric gases. Gases can be removed from the atmosphere of Venus either by dispersing them in space, which is very wasteful, or by binding them to rocks into non-volatile chemical compounds. The terraformation of Venus is considered separately and here Venus is mentioned for comparison, and taking into account that at some stages the terraformation of Mars and Venus can proceed in parallel.
The terafomation of Mars has a different problem. Here it is necessary, on the contrary, to increase the amount of gases in the atmosphere. There are two ways to do this. Either melt the ice and release gases from the ground, or deliver colossal volumes of gases from other planets. It would seem easier to melt the ice. But there is a problem. We do not yet know the total volume of ice and do not know its composition. If the ice on Mars consists primarily of water ice, then there will be nothing to fill the atmosphere. Water vapor will not fill the atmosphere. Then you will have to deliver gases from outside.
It is often proposed to bombard Mars with comets. However, this cannot radically solve the problem. At least, there are not so many comets flying in the inner part of the Solar System. It is not known how many asteroids in the asteroid belt are made of ice.
Can we count on this? Drive comets out of the Kuiper Belt? So far, at the current level of technology development, this looks too fantastic. But the problem is different. Water ice cannot raise the pressure on the planet. Other gases are needed here, such as carbon dioxide, methane, argon, nitrogen, ammonia, ethane, acetylene.
Now the average temperature of the Earth is +15 º C, and the average temperature of Mars is -53 º C. The average pressure on Mars is slightly lower than or very close to the pressure corresponding to the triple point. Therefore, water cannot exist on Mars in liquid form, but only in the form of ice or steam. Although in deep depressions the pressure can be slightly above the triple point up to 1000 Pa and there water can exist in the form of a liquid at positive temperatures. Currently, the formation of significant volumes of liquid water can occur rather accidentally, for example, during the flow of groundwater or as a result of the thawing of permafrost.
The proximity of the pressure on Mars to the triple point of water indirectly indicates that the polar ice caps consist mostly of water. Moreover, with the pressure existing on Mars, even at the poles the temperature does not reach the freezing temperature of carbon dioxide. It follows that for the most part the caps of Mars consist of ice. This is good news for future Mars colonists. But to fill the atmosphere, a lot of gases must be released. Therefore, the question of the amount of frozen carbon dioxide in the polar caps is key to the future fate of the planet. If there are sufficient reserves of carbon dioxide in solid form on Mars, then the heating of the planet as a result of technogenic activity can raise the pressure above the pressure corresponding to the triple point, then on Mars the melting of glaciers, the appearance of reservoirs of water and, ultimately, the existence of terrestrial-type life on the surface of the planet are possible. Otherwise, the heating of the polar caps will not increase pressure on the planet. Since water easily undergoes a phase transition, especially if it is favored by ambient temperatures (about 0 º C), then it is not possible to increase the water content in the atmosphere and thus increase the pressure.
Therefore, all hope for further terraformation of Mars may be associated with the presence of a sufficient amount of frozen carbon dioxide in the polar caps.
Of course, it can be assumed that in ancient times, when the pressure on Mars was still higher, carbon dioxide froze at a higher temperature. It is assumed that the pressure on Mars could reach 1 - 3 Earth atmospheres. For example, at normal pressure, carbon dioxide freezes at a temperature of -56.6 º C. The Earth's poles cool to this temperature, and it was even colder on Mars. Considering that the main component of the atmosphere is CO 2, it should be assumed that CO 2 mixed with H 2 O forms the polar caps of Mars. Carbon dioxide, unlike water, evaporates and freezes with less energy. But when mixed with regular ice, this process slows down greatly. Therefore, in the depths of the polar caps there can be a significant amount of carbon dioxide.
At some point, the pressure on Mars dropped so much that the process of freezing out carbon dioxide stopped. The state of the atmosphere has stabilized. All that remains is the process of loss of the atmosphere due to the escape of molecules into space. Over millions of years, Mars has lost a significant part of its atmosphere, in particular all light gases and nitrogen.
11. Warming up the polar caps
The first stage of terraformation will be the heating of the polar caps. The simplest and most obvious solution is to use solar energy for these purposes,reflected by the orbital mirror. For this preheating, two other methods are proposed: dumping several asteroids containing ammonia, producing greenhouse gases in Martian factories.
Orbital mirror . To heat up the polar caps, it is necessary to reflect some of the solar energy using a giant mirror and direct it to the region of the polar caps. Solar constant is the total flux of solar radiation passing per unit time through a unit area oriented perpendicular to the flux, at a distance of one astronomical unit from the Sun outside the earth's atmosphere. According to extra-atmospheric measurements, the solar constant is 1367 W/m². The solar constant in Mars' orbit is 43% of the solar constant in Earth's orbit. This is not small and amounts to approximately 0.58 quat per square meter.
On Mars, as well as on Earth, in winter, polar night occurs at one of the poles. In summer, the sun rises higher, the angle of incidence of the rays is greater, and in the region of the polar cap the surface heats up, and the cap partially melts. However, the evaporating gases are transported to the opposite hemisphere, where winter reigns at this time, and condense again. Therefore, to solve problems of terraformation, heating the winter hemisphere is more relevant.
The warming of the surface of Mars is also not without significance, not only in the polar regions, since there may be permafrost under the layer of sand. However, such heating of permafrost using concentrated sunlight will be ineffective.
By placing the mirror on the opposite side relative to the sun, you can direct the sun's rays to the region of the polar cap, where winter is just setting in. The problem is that the mirror must rotate in orbit around the planet. Some scientists suggest finding a relatively stable point for the mirror. It is proposed to place the mirror at a distance of 214 thousand km as such a point. from the surface of Mars.Here the force of attraction will be balanced by the pressure force of sunlight. The main conclusion of the authors of this idea is that it is necessary to raise the temperature by about 4 degrees, then the polar cap will begin to melt, the heating of the planet will release the gas adsorbed in the regolith and all together this will raise the pressure to 500 - 1000 mbar. Optimistic, isn't it, considering that now the pressure is only 6 -10 mbar.
12. Creation of a primitive biosphere
The next stage after the pressure rises at least two to three times will be the settlement of Mars with living organisms. It is probably possible to find terrestrial microorganisms capable of surviving in the conditions of Mars or to develop such microorganisms using genetic engineering methods. Some confirmation of this possibility was the recently discovered microorganisms on Earth at a depth of 200 m - methanogens, feeding on hydrogen and breathing carbon dioxide. A special experiment carried out by scientists proved that such microorganisms could survive in the harsh Martian conditions.
If the pressure on Mars was several times higher than the current one, simple organisms such as algae or lichens could exist there. However, these must be plants that can withstand ultraviolet radiation. Ultraviolet radiation can be absorbed by the outer "crust" based on organic carbon or based on inorganic materials silicon-calcium-aluminum-oxygen-carbon a shell similar to what corals or mollusks create on the basis of calcite. It is important that at pressure above the triple point on Mars, dew will already fall in many places, which plants can absorb. In addition, plants can absorb moisture even from the atmosphere, as some plants surviving in terrestrial deserts do. However, water-based life on Mars will not be possible for a long time. Since water can freeze inside the body. However, this problem can be overcome if plants use for metabolism not water as such, but certain solutions such as antifreeze that will not freeze at subzero temperatures.
There is also the possibility of survival on Mars of living creatures that do not use water. Among terrestrial insects there are types of moths that do not contain water in their bodies.
However, the main problems that will be solved with the help of Martian plants will be the following. Transformation of the atmosphere and saturation with oxygen, transformation of soil into soil, binding of soil. Severe dust storms occur on Mars because, in low gravity conditions, fine dust easily rises into the atmosphere. If the soil were slightly moist, and plants grew on the soil, the blowing of dust into the atmosphere would be reduced significantly. Let me remind you that during dust storms the surface cools down greatly, so dust storms are a negative phenomenon for the future Mars.
To be continued.
| Carbon dioxide | 95,32 % |
| Nitrogen | 2,7 % |
| Argon | 1,6 % |
| Oxygen | 0,13 % |
| Carbon monoxide | 0,07 % |
| water vapor | 0,03 % |
| Nitric oxide(II) | 0,013 % |
| Neon | 0,00025 % |
| Krypton | 0,00003 % |
| Xenon | 0,000008 % |
| Ozone | 0,000003 % |
| Formaldehyde | 0,0000013 % |
Atmosphere of Mars- gas shell surrounding the planet Mars. It differs significantly from the earth’s atmosphere both in chemical composition and physical parameters. The pressure at the surface is 0.7-1.155 kPa (1/110 of the Earth's, or equal to the Earth's at an altitude of over thirty kilometers from the Earth's surface). The approximate thickness of the atmosphere is 110 km. The approximate mass of the atmosphere is 2.5 10 16 kg. Mars has a very weak magnetic field (compared to Earth's), and as a result, the solar wind causes the dissipation of atmospheric gases into space at a rate of 300±200 tons per day (depending on current solar activity and distance from the Sun). 
Chemical composition
4 billion years ago, the atmosphere of Mars contained an amount of oxygen comparable to that of the young Earth.
Temperature fluctuations
Since the atmosphere of Mars is very rarefied, it does not smooth out daily fluctuations in surface temperature. Temperatures at the equator range from +30°C during the day to −80°C at night. At the poles, temperatures can drop to −143°C. However, daily temperature fluctuations are not as significant as on the atmosphereless Moon and Mercury. Low density does not prevent the atmosphere from forming large-scale dust storms and tornadoes, winds, fogs, clouds, and influencing the climate and surface of the planet.
The first measurements of the temperature of Mars using a thermometer placed at the focus of a reflecting telescope were carried out in the early 1920s. Measurements by W. Lampland in 1922 gave an average surface temperature of Mars of 245 (−28°C), E. Pettit and S. Nicholson in 1924 obtained 260 K (−13°C). A lower value was obtained in 1960 by W. Sinton and J. Strong: 230 K (−43°C).
Annual cycle
The mass of the atmosphere changes greatly throughout the year due to the condensation of large volumes of carbon dioxide in the polar caps in winter and evaporation in summer.
Each planet differs from the others in a number of characteristics. People compare other found planets with the one they know well, but not perfectly - this is planet Earth. After all, this is logical, life could appear on our planet, which means that if you look for a planet similar to ours, then it will also be possible to find life there. Because of these comparisons, the planets have their own distinctive features. For example, Saturn has beautiful rings, which is why Saturn is called the most beautiful planet in the solar system. Jupiter is the largest planet in the solar system and this is a feature of Jupiter. So what are the features of Mars? This is what this article is about.
Mars, like many planets in the solar system, has satellites. In total, Mars has two satellites: Phobos and Deimos. The satellites got their names from the Greeks. Phobos and Deimos were the sons of Ares (Mars) and were always close to their father, just as these two satellites were always close to Mars. In translation, “Phobos” means “fear”, and “Deimos” means “horror”.
Phobos is a satellite whose orbit is very close to the planet. It is the closest satellite to a planet in the entire solar system. The distance from the surface of Mars to Phobos is 9380 kilometers. The satellite orbits Mars with a frequency of 7 hours 40 minutes. It turns out that Phobos manages to make a little over three revolutions around Mars, while Mars itself makes one revolution around its axis.
Deimos is the smallest moon in the solar system. The dimensions of the satellite are 15x12.4x10.8 km. And the distance from the satellite to the surface of the planet is 23,450 thousand km. Deimos's orbital period around Mars is 30 hours and 20 minutes, slightly longer than the time it takes the planet to rotate on its axis. If you are on Mars, Phobos will rise in the west and set in the east, while making three revolutions per day, while Deimos, on the contrary, rises in the east and sets in the west, while making only one revolution around the planet.
Features of Mars and its Atmosphere
One of the main features of Mars is that it was created. The atmosphere on Mars is quite interesting. Now the atmosphere on Mars is very thin, it is possible that in the future Mars will completely lose its atmosphere. The peculiarities of the atmosphere of Mars are that once upon a time Mars had the same atmosphere and air as on our home planet. But during its evolution, the Red Planet lost almost all of its atmosphere. Now the pressure of the atmosphere of the Red Planet is only 1% of the pressure of our planet. The peculiarity of the atmosphere of Mars is also that even with a third of the gravity of the planet relative to the Earth, Mars can raise huge dust storms, lifting tons of sand and soil into the air. Dust storms have already spoiled the nerves of our astronomers more than once; since dust storms can be very extensive, observing Mars from Earth becomes impossible. Sometimes such storms can even last for months, which greatly spoils the process of studying the planet. But the exploration of the planet Mars does not stop there. There are robots on the surface of Mars that do not stop exploring the planet.
The atmospheric features of the planet Mars also mean that scientists’ guesses about the color of the Martian sky have been refuted. Scientists believed that the sky on Mars should be black, but images taken by the space station from the planet disproved this theory. The sky on Mars is not black at all, it is pink, thanks to particles of sand and dust that are in the air and absorb 40% of sunlight, which creates the effect of a pink sky on Mars.
Features of the temperature of Mars
Measurements of the temperature of Mars began relatively long ago. It all started with Lampland's measurements in 1922. Then the measurements indicated that the average temperature on Mars was -28º C. Later, in the 50s and 60s, some knowledge about the temperature regime of the planet was accumulated, which was carried out from the 20s to the 60s. From these measurements it turns out that during the day at the equator of the planet the temperature can reach +27º C, but by the evening it will drop to zero, and by the morning it becomes -50º C. The temperature at the poles ranges from +10º C, during the polar day, and to very low temperatures during the polar night.
Relief features of Mars
The surface of Mars, like other planets that do not have an atmosphere, is scarred by various craters from the falls of space objects. Craters can be small (5 km in diameter) or large (from 50 to 70 km in diameter). Due to the lack of its atmosphere, Mars was subject to meteor showers. But the planet's surface contains more than just craters. Previously, people believed that there was never water on Mars, but observations of the planet's surface tell a different story. The surface of Mars has channels and even small depressions that resemble water deposits. This suggests that there was water on Mars, but for many reasons it disappeared. Now it’s difficult to say what needs to be done so that water appears on Mars again and we can watch the resurrection of the planet.
There are also volcanoes on the Red Planet. The most famous volcano is Olympus. This volcano is known to all those interested in Mars. This volcano is the largest hill not only on Mars, but also in the solar system, this is another feature of this planet. If you stand at the foot of the Olympus volcano, it will be impossible to see the edge of this volcano. This volcano is so large that its edges go beyond the horizon and it seems that Olympus is endless.
Features of the Magnetic Field of Mars
This is perhaps the last interesting feature of this planet. The magnetic field is the protector of the planet, which repels all electrical charges moving towards the planet and pushes them away from their original trajectory. The magnetic field is completely dependent on the planet's core. The core on Mars is almost motionless and, therefore, the planet's magnetic field is very weak. The action of the Magnetic field is very interesting, it is not global, as on our planet, but has zones in which it is more active, and in other zones it may not be at all.
Thus, the planet, which seems so ordinary to us, has a whole set of its own features, some of which are leading in our Solar System. Mars is not as simple a planet as you might think at first glance.
A common mistake commonly made in assessing the climate conditions of a particular planet is to confuse pressure with density. Although from a theoretical point of view we all know the difference between pressure and density, in reality it is taken to compare the atmospheric pressure on earth with the atmospheric pressure of a given planet without precautions.
In any terrestrial laboratory, where gravity is approximately the same, this precaution is not needed and often uses pressure as a “synonym” for density. Some phenomena are handled safely in terms of "pressure/temperature" value, such as face diagrams (or state diagrams), where in reality it would be more correct to speak of "density-temperature coefficient" or "under pressure/temperature", in Otherwise we don't understand the presence of liquid water in the absence of gravity (and then weightlessness) in spacecraft orbiting in space!
In fact, technically, atmospheric pressure is the "weight" that a certain amount of gas above our heads exerts on everything underneath. However, the real problem is that weight is not only caused by density but obviously by gravity. If we, for example, reduce the gravity of the Earth by 1/3, Obviously, the same amount of gas that is above us will have one third of its original weight, Despite the amount of gas remains exactly the same. So, then, in comparing the climatic conditions between the two planets it would be more correct to speak of density rather than pressure.
We understand this principle very well by analyzing the functioning of the Torricelli barometer, the first document that measured the earth's atmospheric pressure. If we fill a closed tube with mercury on one side and set it vertically with the open end immersed in a tank filled with mercury also, you will notice the formation of a vacuum chamber at the top of the straw. Torricelli actually noted that the external pressure exerted in the straw was to support a high mercury column of approximately 76 cm. By calculating the specific product of mercury, the Earth's gravitational acceleration and the height of the mercury column, the weight above the atmosphere can be calculated.
From Wikipedia at: http:///Wiki/Tubo_di_Torricelli it.wikipedia.org
This system, brilliant for its time, however had strong limitations when applied to Earthlings. In fact, like the real gravity in two of the three factors of the formula, any difference in gravity produces a quadratic difference in the response of the barometer, then, the same column of air, on a planet with 1/3 of the original gravity, will produce, for the barometer, Torricelli , under pressure 1/9 the original value.
Clearly, apart from instrumental artifacts, the fact remains: the same column of air will have a weight proportional to the gravity of the planets on which from time to time we will have it so simply that barometric pressure is not an absolute indicator of density!
This effect is systematically ignored in analyzes of the Martian atmosphere. We are talking easily about pressure in hPa and dealing directly from the earth, completely ignoring the pressure in hPa, which is that the gravity on Mars is about 1/3 that of the earth (for an accuracy of 38%). The same mistakes you made when you look at the front diagrams of water to demonstrate that on Mars, water cannot exist in liquid form. In particular, the triple point of water, on earth is 6.1 hPa, but on Mars, where gravity is 38% that of earth. If you do in hPa, it would be absolutely 6.1 but for 2.318 hPa (Although the barometer will mark Torricelli 0.88 hPa). This analysis, however, is always, in my opinion, fraudulently, systematically avoided, restoring the designation to the same meanings of the earth. The same indication of 5-7 GPA for Martian atmospheric pressure is clearly not indicated whether in view of terrestrial gravity or Mars.
In fact, 7 hPa on Mars should have a gas density on earth that would measure about 18.4 hPa. This is absolutely avoided in all modern studies, Say, in the second half of 60 Further, While previously it was strictly stated that the pressure was one tenth of the earth but with a density of 1/3. From a purely scientific point of view, the actual weight of the air column was considered, which results in 1/3 of its actual weight on the ground, but that in reality the density was comparable to 1/3 of that of the earth. How do recent studies suggest this difference exists?
Maybe because it is easier to talk about the impossibility of preserving the liquid phase of water?
There are other clues to this thesis: Every atmosphere actually produces light scattering (scattering) predominantly in blue, which even in the case of Mars can be easily analyzed. Although the atmosphere of Mars is a pile of dust to make it reddish, separating the blue color component of the panoramic image of Mars, you can get an idea of the density of the atmosphere of Mars. If we compare images of the earth's sky taken at different heights, and then with different degrees of density, We understand that the nominal size in which we should find 7 hPa, i.e. 35.000 m, the sky is completely black, Salvo Fair is a horizon strip where in fact we still see in the layers of our atmosphere.
Left: Shooting of the Martian landscape taken by the Pathfinder probe June 22, 1999. Source: http://photojournal.JPL. nasa.gov/catalog/PIA01546 right: Blue channel figure next to it; Notice the intensity of the sky!
Left: Sydney - a city in South Eastern Australia, the capital of the state of New South Wales, at 6 m. Right: Blue channel drawing next.
Left: Sydney, but always during a sandstorm. Right: Blue channel drawing next to it; as you can see, suspended dust reduces the brightness of the sky, not increases it, contrary to what is claimed in the case of NASA Mars!
Obviously, photographs of the Martian sky, filtered by the blue band, are much brighter, almost comparable to images taken at Mount Everest, just under 9.000 m, where to look if the atmospheric pressure is 1/3 of normal sea level pressure.
Further evidence of the serious benefit of a Martian atmospheric density higher than advertised was provided by the phenomenon of dust devils. These “mini Tornadoes” are capable of lifting columns of sand up to several kilometers; But how is this possible?
NASA itself tried to simulate them, in a vacuum chamber, simulating Martian pressure of 7 hPa, and they were unable to simulate the phenomenon unless the pressure was raised at least 11 times! The initial pressure, even when using a very powerful fan, could not remove anything!
In fact, 7 GPa is really simple, given the fact that in addition to rising above sea level it decreases quickly immediately for fractional values; but then all the phenomena are observed near Mount Olympus, which means 17 km in height, How will it be possible?
It is known from telescopic observations that Mars has a very active atmosphere, especially with regard to the formation of clouds and fogs, not just sandstorms. Observing Mars through a telescope in fact, inserting a blue filter, you can highlight all these atmospheric phenomena is far from insignificant. In the morning and evening there was fog, orographic clouds, polar clouds were always observed in a telescope with medium media power. Anyone can, for example, with a regular graphics program, separate the three red levels, green, blue color of the image of Mars and check how it works. The image corresponding to the red channel will give us a good topographical map while the blue channel will show the polar ice caps and clouds. Also, in the images obtained from the space telescope, you notice a blue boundary caused by the atmosphere, which then appears blue and red not as shown in the image location.
Typical images of Mars taken by the Hubble Space Telescope. Source: http://Science.NASA.gov/Science-News/Science-at-NASA/1999/ast23apr99_1/
Red channel (left), Green channel (Center) and Blue channel (right); Note the equatorial cloud.
Another interesting point is the analysis of polar deposits; intersection of altitudinal data and gravitometrici, it was impossible to determine that the polar deposits differ seasonally by approximately 1.5 meters at the North Pole and 2.5 meters at the South Pole, with an average population density at the time of a maximum height of approximately 0.5 g/cm 3 .
In this case, the density of 1 mm of snow in CO 2 produces a pressure of 0.04903325 hPa; Now, even if we assume the most optimistic Martian pressure, the above 18.4 hPa, ignoring the fact that CO 2 represents 95% and not 100% of the atmosphere of Mars, If we all condensassimo the atmosphere on earth we would get a layer 37.5 cm thick!
On the other hand, 1.5 feet of carbon dioxide snow with a density of 0.5 g/cm 3 produces a pressure of 73.5 hPa and 2.5 meters instead of 122.6 hPa!
Time evolution surface atmospheric pressure, recorded two Viking Landers 1 and 2 (Viking Lander 1 He landed in Chrys cosmism at 22.48° n, 49.97° West longitude, 1.5 Km below average. Viking Lander 2 He landed in Utopia cosmism at 47.97° n , 225.74° West longitude, 3 Km below the average level), during the first three years of the Mars mission: 1st year (dots), 2nd year (solid line) and 3 years (dashed line) fit in the same column. Source Tillman and Guest (1987) (See also Tillman 1989).
Consider also that, if the seasonal mass of dry ice were similar between the two hemispheres, it should not cause seasonal variations in global atmospheric pressure, since the collapse of the polar cap will always be offset by condensation on the floor in the other hemisphere.
But we know that the flattening of the Martian orbit creates a difference of almost 20° C in the average temperature of the two hemispheres, from the apex to 30° C in favor of Latitude -30° ~. Keep in mind that 7 GPa CO 2 ICES -123°C (~150°K), Although at 18.4 hPa (the correct value for Mars gravity) ICES up to ~-116°C (~157°K).
Comparison of data collected by the Mariner 9 mission during boreal spring (Ls = 43 – 54°). Shown as a solid line on the graph above the temperature (in Kelvin) discovered by the IRIS experiment. The dash-dot curves show the local winds (in m s-1) as derived from the wind thermal balance (Pollack et. 1981). The middle graph shows the simulated temperature (K) for the same season, while the bottom graph represents the simulated winds (in m s-1). Source: "Meteorological variability and annual surface pressure cycle on Mars" Frederic Hourdin, Le Van Fu, François Forget, Olivier Talagrand (1993)
According to Mariner 9 data, only at the South Pole do we find the necessary weather conditions, Although according to the damages of the global surveyor (MGS) associated with the earth, presence in both hemispheres is possible.
Minimum temperatures in degrees Celsius of soil on Mars, taken from the Thermal Spectrometer (TES) on board the Mars Global Surveyor (MGS). In horizontal and vertical Latitude Longitude of the sun (Ls). The blue part of the table shows the minimum temperature, the average annual maximum and always with reference to the daily minimum temperatures.
Then, to summarize, the atmosphere appears to reach a minimum temperature of -123 °C to zero -132 °C; I note that at -132°2 the pressure should not exceed 1.4 GPa without ice!
Carbon dioxide vapor pressure graph; Among other utilities of this graph, you can determine the maximum pressure CO2 can reach before condensation (in this case on ice) at a given temperature.
But let's return to seasonal polar deposits; As we have already seen, at least at night, at 60° latitude, conditions seem to exist for dry ice to form, but what actually happens during the polar night?
Let's start with two completely different states: condensation from a surface to cool a mass of air, or "cold".
For the first case, assume that the soil temperature drops below the freezing limit of carbon dioxide; The soil will begin to become covered with a layer of ice more and more until the thermal insulation caused by the ice itself will be enough to stop the process. In the case of dry ice, although it is a good thermal insulator, it is simply very small, so this phenomenon itself is not effective enough to justify the observed ice accumulations! As proof of this, the North Pole and South Pole have a record of -132°C, where the minimum is -130°C (According to TES MGS). I'm also interested in how reliable the detection of -132°c from Martian orbit and spectroscopic path is, because at this temperature the soil itself should be veiled from the condensation process!
In the second case, If an air mass (in this case almost pure CO 2) reaches the dew point, as soon as the temperature drops, its pressure does not exceed the limit set by the "vapor pressure" for that gas at that temperature, causing immediate condensation of the mass of any excess gas! In fact, the effectiveness of this process is truly dramatic; If we were to simulate a similar event on Mars, we would also need to consider the chain of events that would create.
We lower the temperature of the South Pole, for example to -130°C, initial pressure 7 hPa; the arrival pressure should be ~ 2 GPa, causing precipitation of dry ice snow ~ 50 cm thick (0.1 GR/cm 2) If compressed at 0.5 GR/cm 2 match ~ 10 cm thick. Of course, such a pressure difference will promptly air from the surrounding areas, with the effect of the lower (chain) pressure and temperature from the neighboring areas, but condensation is the contribution of everyone in the snow. The process itself also tends to make thermal energy (then increase in temperature) at the same time, but if the temperature remains at -130 ° C, the condensation process will only stop when all the planets reach an equilibrium pressure of 2 hPa!
This small simulation is used to understand the relationship between minimum temperatures and changes in atmospheric pressure, explaining why minimum temperature and pressure are related. From the presented atmospheric pressure graphs recorded by two Viking Landers, we know that for Vikings 1 the pressure varies from a minimum of 6.8 GPa and a maximum of 9.0 hPa, with an average value of 7.9. For Vikings 2 Acceptable values are from 7.4 HPA to 10.1 GPa with an average of 8.75 hPa. We also know that VL 1 landed 1.5 Km and VL 2 3 Km, both below the average level of Mars. Considering that the average level of Mars is 6.1 hPa (occurs from the triple point of water!), if we scale the values above to an average of 6.1 hPa, then both range from less than 5.2 ± 0.05 hPa and a maximum of 7 ± 0.05 hPa. While the minimum value is 5.2 GPa, low temperature, we get ~-125 ° C (~ 148 ° K), already in clear disagreement with your data. Now, while the pressure drop from 7 HPA to 5.2 HPA is deposited 18.4 cm thick (0.1 Gy/cm 2) If compressed to 0.5 Gy/cm 2 match ~ 3.7 cm thick, and that the surface of the South polar cap is ~ 1/ 20 Total surface of Mars (definitely getting close by default!), 3.7 cm X 20 = 74 cm, This is a much smaller value within the polar deposits discovered!
Therefore, there is an obvious contradiction between thermal data and weather data, unless one supports the other! Such a low temperature will result in strong pressure fluctuations (even between day and night!) or even lower overall pressure! On the other hand, however, 7 is absolutely insufficient to account for phenomena such as Devils dust nominal HPA, gullies, sky light spreads or the magnitude of transitional polar deposits, which you explained better well above the atmospheric pressure of 7 hPa.
So far, only aspects related to carbon dioxide, considered one of the main components of the atmosphere (~95%) have been considered; But if we introduce even water into this analysis, the 7 GPa designation becomes completely ridiculous!
For example, traces left by the flow of liquid water (see the Newton crater) where the water should only be a vapor state, given very low pressure and temperatures of up to about 27 ° C!
In such a situation, we can safely say that the pressure (in ground conditions) cannot be less than 35 hPa!