Planets that have an atmosphere. Distinctive features of the planets of the solar system. boundary layer of the atmosphere

A. Mikhailov, prof.

Science and life // Illustrations

Lunar landscape.

Melting polar spot on Mars.

Orbits of Mars and Earth.

Lowell's map of Mars.

Kuhl's model of Mars.

Drawing of Mars by Antoniadi.

Considering the question of the existence of life on other planets, we will only talk about the planets of our solar system, since we do not know anything about the presence of other suns, which are stars, of their own planetary systems similar to ours. According to modern views on the origin of the solar system, it can even be assumed that the formation of planets revolving around a central star is an event, the probability of which is negligible, and that therefore the vast majority of stars do not have their own planetary systems.

Further, it is necessary to make a reservation that we involuntarily consider the question of life on planets from our earthly point of view, assuming that this life manifests itself in the same forms as on Earth, i.e., assuming life processes and the general structure of organisms similar to those on earth. In this case, for the development of life on the surface of a planet, certain physicochemical conditions must exist, the temperature must not be too high and not too low, the presence of water and oxygen must be present, the basis organic matter must be carbon compounds.

planetary atmospheres

The presence of an atmosphere on planets is determined by the stress of gravity on their surface. Large planets have enough gravitational force to keep a gaseous shell around them. Indeed, gas molecules are in constant rapid motion, the speed of which is determined by the chemical nature of this gas and temperature.

Light gases - hydrogen and helium - have the highest speed; as the temperature rises, the speed increases. Under normal conditions, i.e., a temperature of 0 ° and atmospheric pressure, the average speed of a hydrogen molecule is 1840 m / s, and oxygen 460 m / s. But under the influence of mutual clashes individual molecules acquire speeds that are several times higher than the indicated average numbers. If a hydrogen molecule appears in the upper layers of the earth's atmosphere with a speed exceeding 11 km / s, then such a molecule will fly away from the Earth into interplanetary space, since the force of earth's gravity will be insufficient to hold it.

The smaller the planet, the less massive it is, the less this limiting or, as they say, critical speed. For the Earth, the critical speed is 11 km/s, for Mercury it is only 3.6 km/s, for Mars 5 km/s, for Jupiter, the largest and most massive of all planets, it is 60 km/s. It follows from this that Mercury, and even lesser bodies, like the satellites of the planets (including our Moon) and all small planets (asteroids), cannot keep the atmospheric shell near their surface with their weak attraction. Mars is able, albeit with difficulty, to hold an atmosphere much thinner than that of Earth, but as for Jupiter, Saturn, Uranus and Neptune, their attraction is strong enough to hold powerful atmospheres containing light gases, such as ammonia. and methane, and possibly also free hydrogen.

The absence of an atmosphere inevitably entails the absence of liquid water. In airless space, the evaporation of water occurs much more vigorously than at atmospheric pressure; therefore, water quickly turns into vapor, which is a very light basin, subject to the same fate as other gases of the atmosphere, i.e., it leaves the surface of the planet more or less quickly.

It is clear that on a planet devoid of atmosphere and water, the conditions for the development of life are completely unfavorable, and we cannot expect either plant or animal life on such a planet. All small planets, satellites of planets, and from large planets - Mercury fall under this category. Let us say a little more about the two bodies of this category, namely the Moon and Mercury.

Moon and Mercury

For these bodies, the absence of an atmosphere has been established not only by the above considerations, but also by direct observations. When the Moon moves across the sky, making its way around the Earth, it often covers the stars. The disappearance of a star behind the disk of the Moon can be observed even through a small tube, and it always happens quite instantly. If the lunar paradise were surrounded by at least a rare atmosphere, then, before completely disappearing, the star would shine for some time through this atmosphere, and the apparent brightness of the star would gradually decrease, in addition, due to the refraction of light, the star would seem displaced from its place . All these phenomena are completely absent when the stars are covered by the Moon.

Lunar landscapes observed through telescopes amaze with the sharpness and contrast of their illumination. There are no penumbra on the Moon. There are deep black shadows next to bright, sunlit places. This happens because, due to the absence of an atmosphere on the Moon, there is no blue daytime sky, which would soften the shadows with its light; the sky is always black. There is no twilight on the Moon, and after sunset, a dark night immediately sets in.

Mercury is farther from us than the Moon. Therefore, we cannot observe such details as on the Moon. We do not know the type of its landscape. The occultation of stars by Mercury, due to its apparent smallness, is extremely rare, and there is no indication that such occultations have ever been observed. But there are transits of Mercury in front of the solar disk, when we observe that this planet in the form of a tiny black dot slowly creeps over the bright solar surface. In this case, the edge of Mercury is sharply delineated, and those phenomena that were seen during the passage of Venus in front of the Sun were not observed in Mercury. But it is still possible that small traces of the atmosphere around Mercury have been preserved, but this atmosphere has a completely negligible density compared to the earth.

On the Moon and Mercury, temperature conditions are completely unfavorable for life. The moon rotates extremely slowly around its axis, due to which day and night continue on it for fourteen days. The heat of the sun's rays is not moderated by the air envelope, and as a result, during the day on the Moon, the surface temperature rises to 120 °, i.e., above the boiling point of water. During the long night the temperature drops to 150° below zero.

During a lunar eclipse, it was observed how, in just over an hour, the temperature dropped from 70° warm to 80° below zero, and after the end of the eclipse, almost in the same short time, returned to its original value. This observation points to the extremely low thermal conductivity of the rocks that form the lunar surface. Solar heat does not penetrate deep into, but remains in the thinnest upper layer.

One must think that the surface of the Moon is covered with light and loose volcanic tuffs, maybe even ash. Already at a depth of a meter, the contrasts of heat and cold are smoothed out “so much so that it is likely that an average temperature prevails there, which differs little from the average temperature of the earth's surface, i.e., a few degrees above zero. It may be that some embryos of living matter have been preserved there, but their fate, of course, is unenviable.

On Mercury, the difference in temperature conditions is even sharper. This planet always faces the Sun on one side. On the daytime hemisphere of Mercury, the temperature reaches 400 °, i.e., it is above the melting point of lead. And on the night hemisphere, frost should reach the temperature of liquid air, and if there was an atmosphere on Mercury, then on the night side it should turn into liquid, and maybe even freeze. Only on the border between the day and night hemispheres within a narrow zone can there be temperature conditions that are at least somewhat favorable for life. However, there is no reason to think about the possibility of developed organic life there. Further, in the presence of traces of the atmosphere, free oxygen could not be retained in it, since at the temperature of the daytime hemisphere, oxygen vigorously combines with most chemical elements.

So, with regard to the possibility of life on the Moon, the prospects are rather unfavorable.

Venus

Unlike Mercury, Venus has certain signs of a thick atmosphere. When Venus passes between the Sun and the Earth, it is surrounded by a light ring - this is its atmosphere, which is illuminated by the Sun in the light. Such passages of Venus in front of the solar disk are very rare: the last passage took place in 18S2, the next one will occur in 2004. However, almost every year Venus passes, although not through the solar disk itself, but close enough to it, and then it is visible in the form of a very narrow sickle, like the moon immediately after the new moon. According to the laws of perspective, the crescent of Venus illuminated by the Sun should make an arc of exactly 180 °, but in reality a longer bright arc is observed, which occurs due to the reflection and bending of the sun's rays in the atmosphere of Venus. In other words, there is twilight on Venus, which increases the length of the day and partially illuminates its night hemisphere.

The composition of the atmosphere of Venus is still poorly understood. In 1932, with the help spectral analysis the presence of a large amount of carbon dioxide was found in it, corresponding to a layer 3 km thick under standard conditions (i.e., at 0° and 760 mm of pressure).

The surface of Venus always appears to us as dazzlingly white and without noticeable permanent spots or outlines. It is believed that in the atmosphere of Venus there is always a thick layer of white clouds, completely covering the solid surface of the planet.

The composition of these clouds is unknown, but most likely they are water vapor. What is under them, we do not see, but it is clear that the clouds must moderate the heat of the sun's rays, which on Venus, which is closer to the Sun than the Earth, would otherwise be excessively strong.

Temperature measurements gave about 50-60° heat for the day hemisphere, and 20° frost for the night. Such contrasts are explained by the slow rotation of Venus around the axis. Although the exact period of its rotation is unknown due to the absence of noticeable spots on the surface of the planet, but, apparently, the day continues on Venus no less than our 15 days.

What are the chances of life on Venus?

Scholars differ on this point. Some believe that all the oxygen in its atmosphere is chemically bound and exists only as part of carbon dioxide. Since this gas has a low thermal conductivity, in this case the temperature near the surface of Venus should be quite high, perhaps even close to the boiling point of water. This could explain the presence of a large amount of water vapor in the upper layers of its atmosphere.

Note that the above results of determining the temperature of Venus refer to the outer surface of the cloud cover, i.e. to a fairly high altitude above its solid surface. In any case, one must think that the conditions on Venus resemble a greenhouse or conservatory, but probably with a much higher temperature.

Mars

The greatest interest from the point of view of the question of the existence of life is the planet Mars. In many ways, it is similar to Earth. From the spots that are clearly visible on its surface, it has been established that Mars rotates about its axis, making one revolution in 24 hours and 37 meters. Therefore, there is a change of day and night on it of almost the same duration as on Earth.

The axis of rotation of Mars makes an angle of 66 ° with the plane of its orbit, almost exactly the same as that of the Earth. Due to this axial tilt on Earth, the seasons change. Obviously, on Mars there is the same change, but only every season on Earth is almost twice as long as ours. The reason for this is that Mars, being on average one and a half times farther from the Sun than the Earth, makes its revolution around the Sun in almost two Earth years, more precisely in 689 days.

The most distinct detail on the surface of Mars, noticeable when viewed through a telescope, is a white spot, which in its position coincides with one of its poles. The spot at the south pole of Mars is best seen, because during periods of its closest proximity to the Earth, Mars is tilted towards the Sun and Earth with its southern hemisphere. It has been noticed that with the onset of winter in the corresponding hemisphere of Mars, the white spot begins to increase, and in summer it decreases. There were even cases (for example, in 1894) when the polar spot almost completely disappeared in autumn. It can be thought that this is snow or ice, which is deposited in winter as a thin cover near the poles of the planet. That this cover is very thin follows from the above observation of the disappearance of the white spot.

Due to the remoteness of Mars from the Sun, the temperature on it is relatively low. The summer there is very cold, and yet it happens that the polar snows completely melt. The long duration of summer does not adequately compensate for the lack of heat. It follows from this that little snow falls there, perhaps only a few centimeters, it is even possible that the white polar spots do not consist of snow, but of hoarfrost.

This circumstance is in full agreement with the fact that, according to all data, there is little moisture on Mars, little water. Seas and large water spaces were not found on it. Clouds are very rarely observed in its atmosphere. The very orange color of the planet's surface, due to which Mars appears to the naked eye as a red star (hence its name from the ancient Roman god of war), is explained by most "observers" by the fact that the surface of Mars is a waterless sandy desert, colored with iron oxides.

Mars moves around the Sun in a markedly elongated ellipse. Due to this, its distance from the Sun varies over a fairly wide range - from 206 to 249 million km. When the Earth is on the same side of the Sun as Mars, the so-called opposition of Mars occurs (because Mars at that time is on the opposite side of the sky from the Sun). During oppositions, Mars is observed in the night sky under favorable conditions. Oppositions alternate on average after 780 days, or after two years and two months.

However, not in every opposition, Mars approaches the Earth at its shortest distance. To do this, it is necessary that the opposition coincides with the time of the closest approach of Mars to the Sun, which happens only every seventh or eighth opposition, that is, after about fifteen years. Such oppositions are called great oppositions; they took place in 1877, 1892, 1909 and 1924. The next great confrontation will be in 1939. It is to these dates that the main observations of Mars and related discoveries are timed. Mars was closest to the Earth during the 1924 opposition, but even then its distance from us was 55 million km. Mars is never closer to Earth.

Channels on Mars

In 1877, the Italian astronomer Schiaparelli, making observations with a relatively modest telescope, but under the transparent sky of Italy, discovered on the surface of Mars, in addition to dark spots, albeit incorrectly called seas, a whole network of narrow straight lines or stripes, which he called the straits (canale in Italian). Hence the word "channel" began to be used in other languages ​​to refer to these mysterious formations.

Schiaparelli, as a result of his many years of observations, compiled detailed map the surface of Mars, on which hundreds of channels are drawn, connecting the dark spots of the "seas" between the sables. Later, the American astronomer Lowell, who even built a special observatory in Arizona to observe Mars, discovered channels in the dark spaces of the "seas". He found that both the "seas" and the channels change their visibility depending on the seasons: in summer they become darker, sometimes taking on a gray-greenish tint; in winter they turn pale and become brownish. Lowell's maps are even more detailed than Schiaparelli's maps, they are marked with many channels that form a complex, but fairly regular geometric network.

To explain the phenomena observed on Mars, Lowell developed a theory that was widely accepted, mainly among amateur astronomers. This theory boils down to the following.

The orange surface of the planet Lowell, like most other observers, takes for a sandy wasteland. He considers the dark spots of the "seas" to be areas covered with vegetation - fields and forests. He considers the canals to be an irrigation network carried out by intelligent beings living on the surface of the planet. However, the channels themselves are not visible to us from the Earth, since their width is far from sufficient for this. To be visible from Earth, the channels must be at least tens of kilometers wide. Therefore, Lowell thinks that we see only a wide strip of vegetation, which unfolds its green leaves, when the channel itself, which lies in the middle of this strip, is filled in spring with water flowing from the poles, where it is formed from the melting of polar snows.

However, little by little, doubts began to arise about the reality of such straightforward channels. The most indicative was the fact that observers armed with the most powerful modern telescopes did not see any channels, but only observed an unusually rich picture of different details and shades on the surface of Mars, which, however, were devoid of regular geometric outlines. Only observers who used medium-strength instruments saw and sketched the channels. Hence, a strong suspicion arose that the channels represent only optical illusion(illusion) that occurs with extreme eye strain. A lot of work and various experiments have been carried out to clarify this circumstance.

The most convincing are the results obtained by the German physicist and physiologist Kühl. They arranged a special model depicting Mars. Against a dark background, Kühl pasted a circle he had cut out of an ordinary newspaper, on which were placed several gray spots, reminiscent of the outlines of the "seas" on Mars. If we consider such a model close up, then it is clearly visible what it is - you can read a newspaper text and no illusion is created. But if you move further away, then with the right lighting, straight thin stripes begin to appear, going from one dark spot to another and, moreover, not coinciding with lines of printed text.

Kuhl studied this phenomenon in detail.

He showed that three are the presence of many small details and shades, gradually turning into one another, when the eye cannot catch them “about all the details, there is a desire to combine these details with simpler geometric patterns, as a result of which the illusion of straight stripes appears where there are no correct outlines. The modern eminent observer Antoniadi, who is at the same time a good artist, paints Mars spotty, with a mass of irregular details, but without any rectilinear channels.

You might think that this issue is best solved by three photography assistance. A photographic plate cannot be deceived: it would seem that it should show what actually exists on Mars. Unfortunately, this is not so. Photography, which, when applied to stars and nebulae, has given so much, in relation to the surface of the planets, gives less than what the eye of the observer sees with the same instrument. This is explained by the fact that the image of Mars, obtained even with the help of the largest and longest-focus instruments, on the plate turns out to be very small in size - only up to 2 mm in diameter. Of course, it is impossible to make out large details on such an image. In photographs, there is a defect from which modern photography lovers who shoot with Leica-type devices suffer so much. Namely, the graininess of the image appears, which obscures all the small details.

Life on Mars

However, photographs of Mars, taken through different light filters, clearly proved the existence of an atmosphere on Mars, although much rarer than that of the Earth. Sometimes in the evening in this atmosphere bright points are noticed, which, probably, are cumulus clouds. But in general, the cloudiness on Mars is negligible, which is consistent with the small amount of water on it.

Nearly all observers of Mars now agree that the dark patches of the "seas" do indeed represent areas covered with plants. In this respect, Lowell's theory is confirmed. However, until relatively recently, there was one obstacle. The question was complicated by the temperature conditions on the surface of Mars.

Since Mars is one and a half times farther from the Sun than the Earth, it receives two and a quarter times less heat. The question of to what temperature such an insignificant amount of heat can warm its surface depends on the structure of the Martian atmosphere, which is a “fur coat” of thickness and composition unknown to us.

Recently it was possible to determine the surface temperature of Mars by direct measurements. It turned out that in the equatorial regions at noon the temperature rises to 15-25°C, but in the evening a strong cooling sets in, and the night, apparently, is accompanied by constant hard frosts.

Conditions on Mars are similar to those we have on high mountains: rarefied and transparent air, significant heating from direct sunlight, cold in the shade and severe night frosts. The conditions are no doubt very harsh, but it can be assumed that the plants have acclimatized, adapted to them, as well as to the lack of moisture.

So, the existence of plant life on Mars can be considered almost proven, but as for animals, and even more so intelligent ones, we can’t say anything definite yet.

As for the other planets of the solar system - Jupiter, Saturn, Uranus and Neptune, it is difficult to assume the possibility of life on them for the following reasons: firstly, low temperature due to the distance from the Sun and, secondly, poisonous gases recently discovered in their atmospheres - ammonia and methane. If these planets have a solid surface, then it is hidden somewhere at a great depth, while we see only the upper layers of their extremely powerful atmospheres.

Even less likely is life on the planet farthest from the Sun, the recently discovered Pluto, about whose physical conditions we still know nothing.

So, of all the planets in our solar system (except the Earth), one can suspect the existence of life on Venus and consider the existence of life on Mars almost proven. But, of course, this is all about the present. Over time, with the evolution of planets, conditions can change dramatically. We will not talk about this due to lack of data.

Earth- the planet of the solar system, located at a distance of 150 million kilometers from the sun. The earth revolves around him average speed 29.765 km/s. It makes a complete revolution around the Sun in a period equal to 365.24 mean solar days. Earth satellite - Moon, circulates at a distance of 384,400 km. The inclination of the earth's axis to the plane of the ecliptic is 66° 33" 22", the period of revolution around the axis is 23 h 56 min 4.1 s. Shape - geoid, spheroid. The equatorial radius is 6378.16 km, the polar one is 6356.777 km. Surface area - 510.2 million km 2. The mass of the Earth is 6 * 10 24 kg. Volume - 1.083 * 10 12 km 3. The gravitational field of the Earth determines the existence of the atmosphere and the spherical shape of the planet.

The average density of the Earth is 5.5 g/cm 3 . This is almost twice as high as the density of surface rocks (about 3 g/cm3). The density increases with depth. The inner part of the lithosphere forms the core, which is in a molten state. Studies have shown that the core is divided into two zones: the inner core (radius about 1300 km), which is probably solid, and the liquid outer core (radius about 3400 km). The hard shell is also heterogeneous, it has a sharp interface at a depth of about 40 km. This boundary is called the Mohorovichic surface. The region above the Mohorović surface is called bark, below - mantle. The mantle, like the crust, is in a solid state, with the exception of individual lava "pockets". With depth, the density of the mantle increases from 3.3 g/cm 3 near the surface of Mohorovicic and up to 5.2 g/cm 3 at the boundary of the core. At the boundary of the core, it jumps up to 9.4 g/cm 3 . The density at the center of the Earth is in the range from 14.5 g/cm 3 to 18 g/cm 3 . At the lower boundary of the mantle, the pressure reaches 1300,000 atm. When descending into the mines, the temperature rises rapidly - by about 20 ° C per 1 kilometer. The temperature in the center of the Earth, apparently, does not exceed 9000°C. Since the rate of temperature increase with depth decreases on average as one approaches the center of the Earth, heat sources should be concentrated in the outer parts of the lithosphere, most likely in the mantle. The only conceivable reason for the heating of the mantle is radioactive decay. 71% of the earth's surface is occupied by oceans, which form the bulk of the hydrosphere. Earth- the only planet in the solar system that has a hydrosphere. The hydrosphere supplies water vapor to the atmosphere. Water vapor through infrared absorption creates a significant greenhouse effect, raising the average temperature of the Earth's surface by about 40°C. The presence of the hydrosphere played a decisive role in the emergence of life on Earth.

The chemical composition of the Earth's atmosphere at sea level is oxygen (about 20%) and nitrogen (about 80%). The modern composition of the Earth's atmosphere seems to be very different from the primary one, which took place 4.5 * 10 9 years ago, when the crust was formed. The biosphere - plants, animals and microorganisms - significantly affects both general characteristics planet earth, and chemical composition her atmosphere.

Moon

The diameter of the Moon is 4 times less than the Earth's, and the mass is 81 times less. Moon- the celestial body closest to the Earth.

The density of the Moon is less than that of the Earth (3.3 g/cm3). It does not have a core, but a constant temperature is maintained in the bowels. Significant temperature drops were recorded on the surface: from +120°С in the subsolar point of the Moon to -170°С on the opposite side. This is explained, firstly, by the absence of an atmosphere, and secondly, by the duration of the lunar day and lunar night, equal to two Earth weeks.

The relief of the lunar surface includes lowlands and mountainous areas. Traditionally, the lowlands are called "seas", although they are not filled with water. From Earth, the "seas" are visible as dark spots on the Moon's surface. Their names are quite exotic: the Sea of ​​Cold, the Ocean of Storms, the Sea of ​​Moscow, the Sea of ​​Crises, etc.

Mountainous regions occupy most of the Moon's surface and include mountain ranges and craters. The names of many lunar mountain ranges are similar to those of the earth: Apennines, Carpathians, Altai. The highest mountains reach a height of 9 km.

Craters occupy the largest area of ​​the lunar surface. Some of them have a diameter of about 200 km (Clavius ​​and Schickard). some are several times smaller (Aristarchus, Anaximei).

The lunar surface is most convenient for observation from the Earth in places where day and night border, i.e., near the terminator. In general, only one hemisphere of the Moon can be seen from the Earth, but exceptions are possible. As a result of the fact that the Moon moves in its orbit unevenly and its shape is not strictly spherical, its periodic pendulum oscillations about its center of mass are observed. This leads to the fact that about 60% of the lunar surface can be observed from the Earth. This phenomenon is called the libration of the moon.

There is no atmosphere on the moon. Sounds do not propagate on it, because there is no air.

Moon phases

The moon does not have its own luminosity. therefore, it is visible only in the part where the rays of the sun or reflected by the Earth fall. This explains the phases of the moon. Every month, the Moon, moving in its orbit, passes between the Earth and the Sun and faces us dark side(new moon). A few days later, a narrow crescent of the young moon appears in the western part of the sky. The rest of the lunar disk is dimly lit at this time. After 7 days, the first quarter comes, after 14-15 - the full moon. On the 22nd day, the last quarter is observed, and after 30 days, the full moon again.

Moon exploration

The first attempts to study the surface of the Moon took place quite a long time ago, but direct flights to the Moon began only in the second half of the 20th century.

In 1958, the first landing of a spacecraft on the surface of the Moon took place, and in 1969 the first people landed on it. These were the American cosmonauts N. Armstrong and E. Oldrnn, who were brought there spaceship"Apollo 11".

The main objectives of the flights to the Moon were to take soil samples and study the topography of the Moon's surface. Photographs of the invisible side of the Moon were first taken by the Luna-Z and Luna-9 spacecraft. Soil sampling was carried out by the Luna-16, Luna-20 and other devices.

Sea tides and tides on Earth.

On Earth, high and low tides alternate on average every 12 hours and 25 minutes. The phenomenon of ebbs and flows is associated with the attraction of the Earth to the Sun and Moon. But due to the fact that the distance to the Sun is too large (150 * 10 6 km), the solar tides are much weaker than the lunar ones.

On the part of our planet that faces the Moon, the force of attraction is greater, and less on the peripheral direction. As a result of this, the water shell of the Earth is stretched along the line connecting the Earth with the Moon. Therefore, in the part of the Earth facing the Moon, the water of the World Ocean bulges (a tide occurs). Along the circle, the plane of which is perpendicular to the Earth-Moon line and passes through the center of the Earth, the water level in the oceans decreases (there is a low tide).

The tides slow down the rotation of the Earth. According to the calculations of scientists earlier, the Earth day was no more than 6 hours.

Mercury

• Distance from the Sun - 58 * 10 6 km
• Average density - 54 200 kg / m 3
• Mass - 0.056 Earth masses
• The period of revolution around the Sun is 88 Earth days
• Diameter - 0.4 Earth diameter
• Satellites - no

• Physical conditions:

• closest planet to the sun
• No atmosphere
• The surface is littered with craters
• The daily temperature range is 660°С (from +480°С to -180°С)
• The magnetic field is 150 times weaker than the earth's

Venus

• Distance from the Sun - 108 * 10 6 km
• Average density - 5240 kg / m 3
• Mass - 0.82 Earth masses
• The period of revolution around the Sun is 225 Earth days
• The period of revolution around its own axis is 243 days, the rotation is reverse
• Diameter - 12,100 km
• Satellites - no

Physical conditions

The atmosphere is denser than Earth. The composition of the atmosphere: carbon dioxide - 96%, nitrogen and inert gases> 4%, oxygen - 0.002%, water vapor - 0.02%. The pressure is 95-97 atm., the surface temperature is 470-480°C, which is due to the presence of the greenhouse effect. The planet is surrounded by a layer of clouds consisting of droplets of sulfuric acid with impurities of chlorine and sulfur. The surface is mostly smooth, with few ridges (10% of the surface) and craters (17% of the surface). The soil is basalt. magnetic field no.

Mars

• Distance from the Sun - 228 * 10 6 km
• Average density - 3950 kg / m 3
• Mass - 0.107 Earth masses
• The period of revolution around the Sun is 687 Earth days
• The period of revolution around its own axis is 24 h 37 min 23 s
• Diameter - 6800 km
• Satellites - 2 satellites: Phobos, Deimos

Physical conditions

The atmosphere is rarefied, the pressure is 100 times less than the earth. The composition of the atmosphere: carbon dioxide - 95%, nitrogen - more than 2%. oxygen - 0.3%, water vapor - 1%. The daily temperature range is 115°C (from +25°C during the day to -90°C at night). In the atmosphere, rare clouds and fog are observed, which indicates the release of moisture from groundwater reservoirs. The surface is littered with craters. The soil includes phosphorus, calcium, silicon, as well as iron oxides, which give the planet its red color. The magnetic field is 500 times weaker than the earth's.

Jupiter

• Distance from the Sun - 778 * 10 6 km
• Average density - 1330 kg / m 3
• Mass - 318 Earth masses
• The period of revolution around the Sun is 11.86 years
• Period of revolution around its axis - 9 h 55 min 29 s
• Diameter - 142,000 km
• Satellites - 16 satellites. Io, Gunnmed, Callisto, Europe are the largest
• 12 satellites rotate in one direction and 4 - in the opposite direction

Physical conditions

The atmosphere contains 90% hydrogen, 9% helium and 1% other gases (mainly ammonia). Clouds are made of ammonia. The radiation of Jupiter is 2.9 times greater than the energy received from the Sun. The planet is strongly flattened at the poles. The polar radius is 4400 km less than the equatorial one. Large cyclones are formed on the planet with a lifetime of up to 100 thousand years. The Great Red Spot observed on Jupiter is an example of such a cyclone. There may be a solid core in the center of the planet, although the bulk of the planet is in a liquid state. The magnetic field is 12 times stronger than the earth's.

Saturn

• Distance from the Sun - 1426 * 10 6 km
• Average density - 690 kg / m 3
• Mass - 95 Earth masses
• The period of revolution around the Sun is 29.46 years
• Period of revolution around its axis - 10 h 14 min
• Diameter - 50,000 km
• Satellites - about 30 satellites. Most are icy.
• Some: Pandora, Prometheus, Janus, Epimetheus, Dione, Helen, Mimas, Encelau, Tefnia, Rhea, Titan, Yanet, Phoebe.

Physical conditions

The atmosphere contains hydrogen, helium, methane, ammonia. It receives 92 times less heat from the Sun than the Earth, reflects 45% of this energy. It gives off twice as much heat as it receives. Saturn has rings. The rings are divided into hundreds of individual rings. Discovered by X. Huygens. Rings are not solid. They have a meteorite structure, that is, they consist of solid particles of various sizes. The magnetic field is comparable to that of the earth.

Uranus

• Distance from the Sun - 2869 * 10 6 km
• Average density - 1300 kg / m 3
• Mass - 14.5 Earth masses
• The period of revolution around the Sun is 84.01 years
• Period of revolution around its own axis -16 h 48 min
• Equatorial diameter - 52,300 km
• Satellites - 15 satellites. Some of them are: Oberon (the most distant and second largest), Miranda, Cordelia (the closest to the planet), Ariel, Umbriel, Titania
• 5 satellites move in the direction of the planet's rotation near the plane of its equator in almost circular orbits, 10 revolve around Uranus inside Miranda's orbit

Physical conditions

The composition of the atmosphere: hydrogen, helium, methane. Atmospheric temperature -150°С by radio emission. Methane clouds have been found in the atmosphere. The bowels of the planet are hot. The axis of rotation is inclined at an angle of 98°. Found 10 dark rings separated by gaps. The magnetic field is 1.2 times weaker than the earth's and extends over 18 radii. There is a radiation belt.

Neptune

• Distance from the Sun - 4496 * 10 6 km
• Average density - 1600 kg / m 3
• Mass - 17.3 Earth masses
• The period of revolution around the Sun is 164.8 years
• Satellites - 2 satellites: Triton, Nereid

Physical conditions

The atmosphere is extended and consists of hydrogen (50%), helium (15%), methane (20%), ammonia (5%). The temperature of the atmosphere is about -230°C according to calculations, and according to radio emission -170°C. This indicates the hot bowels of the planet. Neptune was discovered on September 23, 1846 by I. G. Gallev from the Berlin Observatory using the calculations of the astronomer J. J. Le Verrier.

Pluto

• Distance from the Sun - 5900 * 10 6
• Average density - 1000-1200 kg / m 3
• Mass - 0.02 Earth masses
• The period of revolution around the Sun is 248 years
• Diameter - 3200 km
• The period of revolution around its axis is 6.4 days
• Satellites - 1 satellite - Charon, was discovered in 1978 by JW Krnsti from the Marine Laboratory in Washington.

Physical conditions

No visible signs of an atmosphere were found. Above the surface of the planet, the maximum temperature is -212°C, and the minimum is -273°C. Pluto's surface is thought to be covered by a layer of methane ice, and water ice is also possible. Acceleration free fall on the surface is 0.49 m/s 2 . The speed of Pluto's orbit is 16.8 km/h.

Pluto was discovered in 1930 by Clyde Tombaugh and named after the ancient Greek god of the underworld because it is poorly illuminated by the Sun. Charon, according to the ancient Greeks, was the carrier of the dead to the kingdom of the dead across the river Styx.

Earth's atmosphere is very different from the atmospheres of other planets in the solar system. Having a nitrogen-oxygen basis, earth atmosphere creates conditions for life, which, due to certain circumstances, cannot be on other planets.

Instruction

Venus is the planet closest to the sun, which has an atmosphere, and such a high density that even Mikhail Lomonosov in 1761 claimed its existence. The presence of an atmosphere on Venus is such an obvious fact that, until the twentieth century, mankind was under the illusion that the Earth and Venus were twin planets, and life was also possible on Venus.

Space research has shown that things are far from rosy. The atmosphere of Venus is ninety-five percent carbon dioxide, and does not release heat from the Sun to the outside, creating a greenhouse effect. Because of this, the temperature on the surface of Venus is 500 degrees Celsius, and the likelihood of life on it is negligible.

Mars has an atmosphere similar in composition to Venus, also consisting mainly of carbon dioxide, but with impurities of nitrogen, argon, oxygen and water vapor, however, in very small quantities. Despite the acceptable temperature of the surface of Mars at certain times of the day, it is impossible to breathe such an atmosphere.

In defense of supporters of ideas about life on other planets, it is worth noting that planetary scientists, having studied the chemical composition of the rocks of Mars, in 2013 stated that 4 billion years ago there was the same amount of oxygen on the red planet as on Earth.

The giant planets do not have a solid surface, and their atmosphere is similar in composition to that of the sun. Jupiter's atmosphere, for example, is mostly hydrogen and helium, with small amounts of methane, hydrogen sulfide, ammonia, and water, which is thought to be found in the vast planet's inner layers.

Saturn's atmosphere is very similar to that of Jupiter, and also, for the most part, consists of hydrogen and helium, although in slightly different proportions. The density of such an atmosphere is unusually high, and we can only speak with a high degree of certainty about its upper layers, in which clouds of frozen ammonia float, and the wind speed sometimes reaches one and a half thousand kilometers per hour.

Uranus, like the other giant planets, has an atmosphere consisting of hydrogen and helium. During the research that was carried out using the Voyager spacecraft, an interesting feature of this planet was discovered: the atmosphere of Uranus is not heated by any internal sources planets, and receives all energy only from the Sun. That is why Uranus has the coldest atmosphere in the entire solar system.

Neptune has a gaseous atmosphere, but its blue color suggests that it contains a yet unknown substance that gives the atmosphere of hydrogen and helium such a shade. Theories about the absorption of the red color of the atmosphere by methane have not yet received their full confirmation.

ATMOSPHERE OF THE PLANETS OF THE SOLAR SYSTEM. We travel to the planets of the solar system to explore their atmospheric compositions, as well as our own. Virtually every planet in our solar system can be thought of as having an atmosphere. And also see what specific effects can cause different conditions on different planets. MERCURY

Mercury has an incredibly thin atmosphere estimated to be more than a trillion times thinner than Earth. Its gravity is about 38% of Earth's, so it's not capable of retaining much of the atmosphere, and furthermore, its proximity to the Sun means the solar wind can blow gases away from the surface. Particles solar wind combined with the evaporation of surface rocks from meteor impacts, are probably the largest source of Mercury's atmosphere VENUS

Venus is similar to Earth in several respects: its density, size, mass and volume are comparable. However, this is where the similarities end. Atmospheric pressure on the surface of the planet is about 92 times higher than on Earth, and the main gas is carbon dioxide - the result of previous volcanic eruptions on the surface of the planet. Nitrogen is also present in small amounts. Higher in the atmosphere, the planet has clouds that are a mixture of sulfur dioxide and sulfuric acid. Beneath these clouds is a thick layer of carbon dioxide, which exposes the planet's surface to an intense greenhouse effect. The surface temperature on Venus is around 480 degrees Celsius - too hot to support life as we know it. EARTH

The Earth's atmosphere consists mainly of nitrogen and oxygen, which are essential for the life that inhabits the planet. The composition of the atmosphere is a direct consequence of plant life. Plants absorb carbon dioxide and displace oxygen through photosynthesis, and if this were not the case, it is likely that the percentage of carbon dioxide in the atmosphere would be much higher. The earth's atmosphere is divided into layers: Troposphere The troposphere is about 9 km on the Earth's surface in the polar regions and about 17 km at the equator, with an average height of about 12 km. It is in the troposphere that all life on Earth exists. More than 80% of the total mass is concentrated in the troposphere atmospheric air, turbulence and convection are highly developed, the predominant part of water vapor is concentrated, clouds appear, cyclones and anticyclones develop, as well as other processes that determine weather and climate. Stratosphere The stratosphere, separated from the troposphere by the tropopause, extends up to 50-55 km and is where you find the ozone layer. The stratosphere ends at the stratopause, on the other side of which the mesosphere begins. Mesosphere The mesosphere is the highest layer in which noctilucent clouds form, just below the mesopause, which is 80 to 85 km away. The mesosphere also contains most of the meteors that start to glow and burn up when they enter the Earth's atmosphere. Beyond the mesopause, the thermosphere begins. Thermosphere The height of the thermosphere is at an altitude of 90 to 800 km. The temperature in the thermosphere can reach 1773 K (1500 °C, 2700 °F), however, the atmosphere at this altitude is very thin. The thermosphere contains the auroras, the ionosphere, and the International Space Station. Exosphere And finally the exosphere, which extends up to about 10,000 km. Most artificial satellites of the Earth rotate inside the exosphere. Is the Earth's atmosphere unique? MARS

The atmosphere of Mars, like that of Venus, is composed mostly of carbon dioxide, with a small amount of argon, as well as nitrogen. The layers are easy to remember - they are the lower atmosphere, the middle atmosphere, the upper atmosphere and the exosphere. With reference to the extreme greenhouse effect present on Venus as a consequence of the high levels of carbon dioxide, it may seem strange that the surface temperature of Mars reaches a maximum of 35C. This is because Mars' atmosphere is significantly thinner than that of Venus, so while the proportion of carbon dioxide is comparable, the actual concentration is much lower. JUPITER

Jupiter, the first of the gas giants and the largest planet in the solar system, has layers, a troposphere, a stratosphere, a thermosphere, and an exosphere similar to Earth, although there is no mesosphere. Jupiter's troposphere visible part, which we associate with Jupiter, is composed mainly of hydrogen and helium, with a small amount of methane, ammonia, hydrogen sulfide and water, with clouds of ammonia crystals. Since Jupiter does not have a solid surface, the lower levels of the troposphere gradually condense into liquid hydrogen and helium. Without a solid surface, the generally accepted surface of Jupiter is based on where atmospheric pressure is 100 kPa. Moreover, the layers of this atmosphere are characterized by pressure greater than height. Jupiter's troposphere is almost 143,000 km. That's more than 22 Earths. SATURN

Like Jupiter, Saturn is also a gas giant, although not quite as gigantic. Less well known is the atmosphere of Saturn, although, again, it is similar in many ways to that of Jupiter. Mostly hydrogen, with much less helium. Saturn's clouds are also made up of ammonia crystals. The sulfur present in the atmosphere gives ammonia clouds a pale yellow tint. This visible cloudy part of Saturn is over 120,000 km. This is more than 20 planets Earth. URANUS

The atmosphere of Uranus, like that of Jupiter and Saturn, is mostly hydrogen and helium. However, somewhat more high levels methane, especially in the upper atmosphere, cause more absorption of red light from the sun, in turn causing the planet to appear blue-blue in color. Uranus has the coldest atmosphere in the solar system, at approximately -224C, and its atmosphere contains far more water ice than Jupiter and Saturn as a consequence. NEPTUNE

For many years, scientists have been asking questions about planetary atmospheres. So, why do planets, whose gravity is much weaker than ours, have atmospheric pressure hundreds of times higher than Earth's (for example, Venus)? On the other hand, there are planets such as Titan, which have seven times less gravity, but the atmosphere here is four times denser than on Earth. It also happens that some celestial bodies with gravity only three times weaker than the earth, they have an atmosphere that is a hundred times thinner. What are the reasons? A great many hypotheses have been put forward in this regard, but their nature is mutually exclusive.

Astronomers from the Andalusian Institute of Astrophysics, led by José Luis Ortiz, using three telescopes, observed the surface of Makemake in detail in the light of a star that stood on an imaginary line between it and our planet, while eclipsing it for a short time. As a result, observations reliably showed that the dwarf planet Makemake has no atmosphere.

As Jose Luis Ortiz himself explained, Makemake, passing between the star and the Earth, temporarily blocked its light from us, as a result, the star first disappeared from sight, and then suddenly reappeared, indicating the absence of any significant atmosphere on the dwarf planet. Until now, Makemake was considered a frozen world with an orbit located in the outer regions of the solar system and having, in the likeness of Pluto close to it, a full-fledged global atmosphere, albeit thin.

Makemake is a dwarf planet that was discovered in 2005. Its size is about two-thirds the diameter of Pluto. However, it revolves around the Sun in a much more distant orbit: further than Pluto, but closer than Eris. The diameter of the planet, according to the latest data, varies from 1,430 plus or minus 9 km to 1,502 plus or minus 45 km. It is possible that both numbers are correct, and the shape of the planet is not quite correct. In this case, the planet's albedo is 0.77 plus or minus 0.03 (relatively close to Pluto), which is approximately in line with dirty snow and indicates the similarity of these objects. The density of the planet is also at least 1.7 plus or minus 0.3 g / cm³ (15% less than that of Pluto). But, despite this, on the surface of Makemake, the maximum atmospheric pressure does not exceed 12 billionths of the earth. This is practically a vacuum, which is especially strange, given the fact that the temperature of the planet (half of Makemake's surface is at least heated to 50 K) is quite high for a trans-Neptunian object without an atmosphere, which is relatively cool Pluto is located at a significant distance from the Sun .

According to scientists, this may be due to the absence of one of the most important sources of atmospheric gases in such objects, such as nitrogen snow, or the huge tilt of the planet's axis. In this case, the formation of a stable atmosphere is very difficult.

And yet, it is not excluded that the atmosphere still exists in some places on Makemak, for example, in areas with a lower albedo, in which the transition surface substances into a gaseous state. Let's test this theory during the next eclipse.

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