What is venus planet. Why does Venus rotate counterclockwise? Hypotheses

The planet Venus is our closest neighbor. Venus comes closer to the Earth than any other planet, at a distance of 40 million km or closer. The distance from the Sun to Venus is 108,000,000 km, or 0.723 AU.

The dimensions of Venus and the mass are close to those of the earth: the diameter of the planet is only 5% less than the diameter of the Earth, the mass is 0.815 of the mass of the Earth, and the force of gravity is 0.91 of the earth. In this case, Venus rotates very slowly around its axis in the direction opposite to the rotation of the Earth (ie, from east to west).

Despite the fact that in the XVII-XVIII centuries. various astronomers have repeatedly reported the discovery of the natural satellites of Venus. It is currently known that there are none on the planet.

Atmosphere of Venus

Unlike other terrestrial planets, the study of Venus with telescopes turned out to be impossible, since even M. V. Lomonosov (1711 - 1765), on June 6, 1761, observing the passage of the planet against the background of the Sun, he established that Venus is surrounded by "a noble air atmosphere, such (if only not more) than is poured around our globe."

The atmosphere of the planet extends to a height 5500 km, and its density in 35 times greater than the density of the earth. Atmospheric pressure in 100 times higher than on Earth, and reaches 10 million Pa. The structure of the planet's atmosphere is shown in Fig. one.

The last time the passage of Venus against the background of the solar disk in Russia, astronomers, scientists and amateurs, were able to observe June 8, 2004. And on June 6, 2012 (that is, with an 8-year interval), this amazing phenomenon can be observed again. The next passage will take place only after 100 years.

Rice. 1. The structure of the atmosphere of Venus

In 1967, the Soviet interplanetary probe "Venera-4" for the first time transmitted information about the atmosphere of the planet, which consists of 96% carbon dioxide (Fig. 2).

Rice. 2. The composition of the atmosphere of Venus

Due to the high concentration of carbon dioxide, which, like a film, retains heat near the surface, a typical greenhouse effect is observed on the planet (Fig. 3). Thanks to the greenhouse effect near the surface of Venus, any existence of liquid water is excluded. The air temperature on Venus is approximately +500 °C. Under such conditions, organic life is excluded.

Rice. 3. Greenhouse effect on Venus

On October 22, 1975, the Soviet probe "Venera-9" landed on Venus and for the first time transmitted to Earth a television report from this planet.

General characteristics of the planet Venus

Thanks to Soviet and American interplanetary stations, it is now known that Venus is a planet with a complex relief.

Mountainous terrain with a height difference of 2-3 km, a volcano with a base diameter of 300-400 km, and
hundredth about 1 km, a huge hollow (1500 km long from north to south and 1000 km from west to east) and relatively flat areas. In the near-equatorial region of the planet there are more than 10 ring structures, similar to the craters of Mercury, with a diameter of 35 to 150 km, but strongly smoothed and flat. In addition, there is a fault in the planet's crust 1500 km long, 150 km wide and about 2 km deep.

In 1981, the Venera-13 and Venera-14 stations examined soil samples from the planet and transmitted the first color photographs of Venus to earth. Because of this, we know that the surface rocks of the planet are close in composition to terrestrial sedimentary rocks, and the sky above the horizon of Venus is orange-yellow-green.

At present, human flights to Venus are unlikely, but at an altitude of 50 km from the planet, the temperature and pressure are close to conditions on Earth, so it is possible to create interplanetary stations here to study Venus and to recharge spacecraft.

Planet Venus interesting facts. Some you may already know, others should be completely new to you. So read and learn new interesting facts about the "morning star".

Earth and Venus are very similar in size and mass, and they orbit the Sun in very similar orbits. Its size is only 650 km smaller than the size of the Earth, and the mass is 81.5% of the mass of the Earth.

But that's where the similarity ends. The atmosphere is made up of 96.5% carbon dioxide, and the greenhouse effect raises the temperature to 461°C.

2. A planet can be so bright that it casts shadows.

Only the Sun and Moon are brighter than Venus. Its brightness can vary from -3.8 to -4.6 magnitudes, but it is always brighter than the brightest stars in the sky.

3. Hostile atmosphere

The mass of the atmosphere is 93 times greater than the Earth's atmosphere. The pressure on the surface is 92 times greater than the pressure on Earth. It is also like diving a kilometer under the surface of the ocean.

4. It rotates in the opposite direction compared to other planets.

Venus rotates very slowly, a day is 243 Earth days. Even stranger is that it rotates in the opposite direction compared to all other planets in the solar system. All planets rotate in a counter-clockwise direction. Except for the heroine of our article. It rotates clockwise.

5. Many spacecraft have managed to land on its surface.

In the midst of the space race, the Soviet Union launched a series of Venus spacecraft and some successfully landed on its surface.

Venera 8 was the first spacecraft to land on the surface and transmit photographs to Earth.

6. People used to think that there are "tropics" on the second planet from the Sun.

While we sent the first spacecraft to study Venus from close range, no one really knew what was hidden below the dense clouds of the planet. Science fiction writers dreamed of lush tropical jungles. The hellish temperature and dense atmosphere surprised everyone.

7. The planet has no satellites.

Venus looks like our twin. Unlike Earth, it has no moons. Mars has moons, and even Pluto has moons. But she... no.

8. The planet has phases.

Although it looks like a very bright star in the sky, if you can look at it with a telescope, you will see something different. When looking at it through a telescope, you can see that the planet goes through phases like the moon. When it is closer, it looks like a thin crescent. And at the maximum distance from the Earth, it becomes dim and in the form of a circle.

9. There are very few craters on its surface.

While the surfaces of Mercury, Mars, and the Moon are littered with impact craters, there are relatively few craters on the surface of Venus. Planetary scientists believe that its surface is only 500 million years old. Constant volcanic activity smoothes and removes any impact craters.

10. The last ship to explore Venus is the Venus Express.

Many spacecraft have gone to the planet, but one of the most modern ships has been working there until recently. Venus Express was launched on April 11, 2006. He made a detailed study of the Venusian atmosphere and clouds, as well as the environment and its surface. The device was discontinued in 2015.

The universe is huge. Scholars who try to embrace it in their research often feel the incomparable loneliness of humanity that pervades some of Yefremov's novels. There is too little chance of finding life like ours in the available space of space.

For a long time, among the contenders for the settlement of organic life was the solar system, shrouded in legends no less than fog.

Venus, in terms of distance from the star, immediately follows Mercury and is our closest neighbor. From Earth, it can be seen without the help of a telescope: in the evening and pre-dawn hours, Venus is the brightest in the sky after the Moon and the Sun. The color of the planet for a simple observer is always white.

In the literature, you can find its designation as the twin of the Earth. There are a number of explanations for this: the description of the planet Venus in many ways repeats the data about our house. First of all, they include a diameter (about 12,100 km), which practically coincides with the corresponding characteristic of the Blue Planet (a difference of about 5%). The mass of the object, named after the goddess of love, also differs little from the earth. Proximity also played a role in partial identification.

The discovery of the atmosphere supported the opinion about the similarity of the two. Information about the planet Venus, confirming the presence of a special air shell, was obtained by M.V. Lomonosov in 1761. The brilliant scientist observed the passage of the planet across the disk of the Sun and noticed a special radiance. The phenomenon was explained by the refraction of light rays in the atmosphere. However, subsequent discoveries have revealed a huge gulf between seemingly similar conditions on the two planets.

Veil of secrecy

Evidence of similarities, such as Venus and the presence of an atmosphere, were supplemented by data on the composition of the air, which effectively crossed out dreams of the existence of life on the Morning Star. Carbon dioxide and nitrogen were detected in the process. Their share in the air shell is distributed as 96 and 3%, respectively.

The density of the atmosphere is a factor that makes Venus so clearly visible from Earth and at the same time inaccessible to research. The layers of clouds that envelop the planet reflect light well, but are impenetrable to scientists who want to find out what they hide. More detailed information about the planet Venus became available only after the start of space research.

The composition of the cloud cover is not fully understood. Presumably, sulfuric acid vapors play a large role in it. The concentration of gases and the density of the atmosphere, which is about a hundred times higher than the earth's, creates a greenhouse effect on the surface.

Eternal heat

The weather on the planet Venus is in many ways similar to the fantastic descriptions of conditions in the underworld. Due to the peculiarities of the atmosphere, the surface never cools down, even from that part of it that is turned away from the Sun. And this despite the fact that the rotation around the axis of the Morning Star makes more than 243 Earth days! The temperature on the planet Venus is +470ºC.

The absence of a change in seasons is explained by the inclination of the planet's axis, which, according to various sources, does not exceed 40 or 10º. Moreover, the thermometer here gives the same results both for the equatorial zone and for the region of the poles.

the greenhouse effect

Such conditions leave no chance for water. According to the researchers, Venus once had oceans, but rising temperatures made their existence impossible. Ironically, the greenhouse effect was made possible by the evaporation of large amounts of water. Steam allows sunlight to pass through, but traps heat near the surface, thereby contributing to an increase in temperature.

Surface

The heat also contributed to the formation of the landscape. Before the advent of radar techniques in the arsenal of astronomy, the nature of the surface that the planet Venus possesses was hidden from scientists. The photographs and images taken helped to compile a fairly detailed relief map.

The high temperature has thinned the crust of the planet, so there are a large number of volcanoes, both active and extinct. They give Venus that hilly appearance that is clearly visible on radar images. Basalt lava flows have formed vast plains, against which elevations are clearly visible, stretching for several tens of square kilometers. These are the so-called continents, comparable in size to Australia, and in terms of terrain reminiscent of the mountain ranges of Tibet. Their surface is dotted with cracks and craters, in contrast to the landscape of part of the plains, which are almost completely smooth.

There are much fewer craters left by meteorites here than, for example, on the Moon. Scientists name two possible reasons for this: a dense atmosphere, which plays the role of a kind of screen, and active processes that have erased traces of falling cosmic bodies. In the first case, the discovered craters most likely appeared during a period when the atmosphere was more rarefied.

Desert

The description of the planet Venus will be incomplete if attention is paid only to radar data. They give an idea of ​​the nature of the relief, but it is difficult for the layman to understand on their basis what he would see if he got here. Studies of spacecraft that landed on the Morning Star helped answer the question of what color the planet Venus would be to an observer located on its surface. As befits a hellish landscape, shades of orange and gray dominate here. The landscape really resembles a desert, waterless and dousing with heat. Such is Venus. The color of the planet, characteristic of the ground, dominates in the sky. The reason for such an unusual color is the absorption of the short-wavelength part of the light spectrum, which is characteristic of a dense atmosphere.

Learning Difficulties

Data on Venus is collected by devices with great difficulty. Staying on the planet is complicated by strong winds, reaching a peak speed at an altitude of 50 km above the surface. Near the ground, the elements are largely calmed down, but even a slight movement of air is a significant obstacle in the dense atmosphere that the planet Venus has. The photos that give an idea of ​​the surface are taken by ships that can only withstand a hostile onslaught for a few hours. However, they are enough for scientists to discover something new after each expedition.

Hurricane-force winds are not the only feature the weather on the planet Venus is famous for. Thunderstorms rage here with a frequency exceeding the similar parameter for the Earth twice. During the period of increasing activity, lightning causes a specific glow of the atmosphere.

"Eccentricities" of the Morning Star

The Venusian wind is the reason why the clouds move around the planet much faster than it itself around the axis. As noted, the last parameter is 243 days. The atmosphere circulates around the planet in four days. The Venusian quirks don't end there.

The length of the year here is somewhat less than the length of the day: 225 Earth days. At the same time, the Sun on the planet does not rise in the east, but in the west. Such an unconventional direction of rotation is unique to Uranus. It was the speed of rotation around the Sun that exceeded the earth's speed that made it possible to observe Venus twice a day: in the morning and in the evening.

The planet's orbit is an almost perfect circle, and the same can be said about its shape. The Earth is slightly flattened at the poles; the Morning Star does not have such a feature.

Coloring

What color is the planet Venus? Partially, this topic has already been disclosed, but not everything is so simple. This characteristic can also be attributed to the number of features that Venus possesses. The color of the planet, as seen from space, is different from the dusty orange found on the surface. Again, it's all about the atmosphere: the veil of clouds does not let the rays of the blue-green spectrum pass below and at the same time paints the planet for an outside observer in off-white. For earthlings, rising above the horizon, the Morning Star has a cold sheen, not a reddish glow.

Structure

Numerous spacecraft missions have made it possible not only to draw conclusions about the color of the surface, but also to study in more detail what is under it. The structure of the planet is similar to the earth. The morning star has a crust (about 16 km thick), a mantle under it and a core - the core. The size of the planet Venus is close to the earth, but the ratio of its inner shells is different. The thickness of the mantle layer is more than three thousand kilometers, its basis is various silicon compounds. The mantle surrounds a relatively small core, liquid and predominantly iron. Significantly inferior to the earthly "heart", it makes a significant contribution to approximately a quarter of it.

Features of the planet's core deprive it of its own magnetic field. As a result, Venus is exposed to the solar wind and is not immune to the so-called hot flow anomaly, explosions of colossal magnitude that occur with alarming frequency and are capable, researchers speculate, of engulfing the Morning Star.

Exploring the Earth

All the characteristics that Venus has: the color of the planet, the greenhouse effect, the movement of magma, and so on, are being studied, among other things, with the aim of applying the data obtained to our planet. It is believed that the structure of the surface of the second planet from the Sun can give an idea of ​​how the young Earth looked like about 4 billion years ago.

Atmospheric gas data tell researchers about a time when Venus was just forming. They are also used in the construction of theories about the development of the Blue Planet.

To a number of scientists, the sizzling heat and lack of water on Venus seem like a possible future for the Earth.

Artificial cultivation of life

Projects for the settlement of other planets with organic life are also connected with forecasts promising the death of the Earth. One candidate is Venus. The ambitious plan is to spread in the atmosphere and on the surface of blue-green algae, which are the central link in the theory of the origin of life on our planet. The delivered microorganisms, in theory, can significantly reduce the level of carbon dioxide concentration and lead to a decrease in pressure on the planet, after which further settlement of the planet will become possible. The only insurmountable obstacle so far to the implementation of the plan is the lack of water necessary for the prosperity of algae.

Certain hopes in this matter are also placed on some types of mold, but so far all developments remain at the level of theory, since sooner or later they face significant difficulties.

Venus - the planet of the solar system is truly mysterious. The studies carried out answered a lot of questions related to it, and at the same time gave rise to new ones, in some ways even more complex. The morning star is one of the few cosmic bodies that bears a female name, and, like a beautiful girl, it attracts glances, occupies the thoughts of scientists, and therefore it is likely that researchers will still tell us a lot of interesting things about our neighbor.

Average distance to the Sun: 108.2 km

(min. 107.4 max. 109)

Equator diameter: 12,103 km

Average speed of revolution around the Sun: 35.03 km/s

Period of rotation around its axis: 243 days. 00h 14 min

(retrograde)

Period of revolution around the Sun: 224.7 days.

Satellites: None

Volume (Earth = 1): 0.857

Average density: 5.25 g/cm3

Average surface temperature: +470°C

Axis Tilt: 177°3"

Orbital inclination with respect to the ecliptic: 3°4"

Surface pressure (Earth=1): 90

Atmosphere: Carbon dioxide (96%), nitrogen (3.2%), also contains oxygen and other elements

It is the second-most distant planet from the Sun and the closest planet to Earth in the solar system. This is the brightest luminary in the sky (after the Sun and the Moon) both at dusk and in the morning.

People have known about the existence of Venus since time immemorial, but for the first time Galileo observed the phases of this planet with a telescope. The first observers through a telescope noted high mountains in their drawings, it seemed to them that the mountains separate the bright part of the planet from the dark one. In fact, it was a phenomenon caused by atmospheric turbulence. The fact is that it is impossible to consider the protruding parts of the relief of Venus due to the dense and illuminated atmosphere. It is impossible to see details through a telescope, only clouds are within sight. For several centuries, there have been a large number of theories about the surface of Venus. Theories were created in the absence of accurate data about this planet. Some scientists have argued that the planet's environmental conditions are similar to Earth's. Others, even after receiving information about the temperature regime of the planet, namely that the temperature of Venus is much higher than that of the Earth, considered it possible that humid tropical jungles could exist on its surface.

Rotation around own axis

Among all the planets that make up the solar system, Venus is the only one, with the exception of Uranus, rotating around its axis in the direction from east to west. As a rule, celestial bodies rotate around the Sun in the same direction as around their own axis - from west to east.
Venus is characterized by an unusual combination of directions and periods of rotation and revolution around the Sun. Astronomers have called the "wrong" motion of Venus "retrograde". A small rotation speed slightly exceeds the speed of revolution around the Sun. The period of rotation of Venus is 243 days, in order to pass in a circle-shaped orbit around the Sun, Venus spends 225 days.
On Earth, the change of day and night is determined by the rotation of the planet around its axis; on Venus, the period of the Sun's stay above the horizon depends on the duration of rotation around the Sun.

Surface of Venus

There is a possibility that after the formation of Venus, its surface was covered with a large amount of water. Over time, a process began, as a result of which, on the one hand, the evaporation of the seas occurs, on the other hand, the release of carbon dioxide anhydrite, which is part of the rocks, into the atmosphere. The greenhouse effect leads to an increase in temperature and an increase in water evaporation. Over time, water disappears from the surface of Venus, most of the carbon anhydrite passes into the atmosphere.

The surface of Venus is a rocky desert, illuminated by yellowish light, with a predominance of orange and brown tones of the relief. On the surface there are undulating plains and rare mountains. By the presence of some depressions, we can conclude that there were prehistoric oceans on the planet.

Interplanetary stations recorded traces of relatively recent volcanic activity. Secondly, by the nature of the reflection of waves with the help of a radar, one can conclude that there are matte areas of the surface, apparently, this is lava that recently emerged from the depths. The dense atmosphere of the planet contributes to rapid erosion, ferrous sulfate actively reflects the echo of the radar.

The rocks of Venus are similar in composition to terrestrial basalt rocks. The landscape morphology observed on the planet, the craters formed as a result of volcanic eruptions and meteorite bombardment, various tectonic phenomena testify to a very complex and active geological past.

Continents

According to the nature of the elevations in the northern hemisphere and south of the equator in relation to the average level of the planet's surface, scientists concluded that there are so-called continents there. They were called the Istar Mainland and the Aphrodite Mainland. The first is a space slightly smaller than the United States of America, on which the highest peaks of the planet are located - Mount Maxwell, their height reaches 11 km. The mainland of Aphrodite is larger than Africa. Mount Maat is located there - this is a volcano 8 km high, from which lava erupted in the recent past.

On this continent there is a complex system of huge canyons of tectonic origin. Their length sometimes reaches hundreds of kilometers, depth 2-4 km, width up to 280 km.

The internal structure of Venus

The structure of Venus, like the Earth, includes a crust, mantle and core. The thickness of the crust is about 20 km, the mantle is a molten substance and extends for 2800 km. The radius of the iron-containing core is approximately 3200 km. In principle, such a core should create a magnetic field, but it is almost not expressed.

Venus is the second planet from the sun in the solar system, named after the Roman goddess of love. It is one of the brightest objects on the celestial sphere, the "morning star" that appears in the sky at dawn and dusk. Venus is similar to Earth in many ways, but not at all as friendly as it seems from a distance. The conditions on it are completely unsuitable for the emergence of life. The surface of the planet is hidden from us by an atmosphere of carbon dioxide and clouds of sulfuric acid, which create the strongest greenhouse effect. The opacity of the clouds does not allow us to study Venus in detail, therefore it still remains one of the most mysterious planets for us.

a brief description of

Venus revolves around the Sun at a distance of 108 million km, and this value is almost constant, since the planet's orbit is almost perfectly circular. At the same time, the distance to the Earth changes significantly - from 38 to 261 million km. The radius of Venus is on average 6052 km, the density is 5.24 g / cm³ (dense than the earth). The mass is equal to 82% of the mass of the Earth - 5 10 24 kg. The acceleration of gravity is also close to the earth's - 8.87 m / s². Venus has no satellites, but until the 18th century, repeated attempts were made to search for them, which were unsuccessful.

The planet makes a full circle in orbit in 225 days, and the day on Venus is the longest in the entire solar system: they last as much as 243 days, longer than the Venusian year. Venus moves in orbit at a speed of 35 km/s. The inclination of the orbit to the plane of the ecliptic is quite significant - 3.4 degrees. The axis of rotation is almost perpendicular to the plane of the orbit, due to which the northern and southern hemispheres are illuminated by the Sun almost equally, and there is no change of seasons on the planet. Another feature of Venus is that the directions of its rotation and circulation do not coincide, unlike other planets. It is assumed that this is due to a powerful collision with a large celestial body that changed the orientation of the axis of rotation.

Venus is classified as a terrestrial planet, and is also called the sister of the Earth because of the similarity in size, mass and composition. But the conditions on Venus can hardly be called similar to those on Earth. Its atmosphere, composed mainly of carbon dioxide, is the densest of all planets of the same type. Atmospheric pressure is 92 times greater than the earth's. Thick clouds of sulfuric acid envelop the surface. For visible radiation, they are opaque, even from artificial satellites, which for a long time made it difficult to see what was under them. Only radar methods for the first time made it possible to study the relief of the planet, since the Venusian clouds turned out to be transparent to radio waves. It was found that there are many traces of volcanic activity on the surface of Venus, but no active volcanoes were found. There are very few craters, which speaks of the "youth" of the planet: its age is about 500 million years.

Education

Venus is very different from other planets in the solar system in terms of its conditions and features of movement. And it is still impossible to answer the question, what is the reason for such uniqueness. First of all, whether it is the result of natural evolution or geochemical processes due to proximity to the Sun.

According to a single hypothesis of the origin of the planets in our system, they all arose from a giant protoplanetary nebula. Due to this, the composition of all atmospheres was the same for a long time. After some time, only the cold giant planets were able to retain the most common elements - hydrogen and helium. From the planets closer to the Sun, these substances were actually "blown away" into outer space, and heavier elements - metals, oxides and sulfides - entered their composition. The atmospheres of the planets were formed primarily due to volcanic activity, and their initial composition depended on the composition of volcanic gases in the depths.

Atmosphere

Venus has a very powerful atmosphere that hides its surface from direct observation. Most of it consists of carbon dioxide (96%), 3% is nitrogen, and even less other substances - argon, water vapor and others. In addition, clouds of sulfuric acid are present in a large volume in the atmosphere, and it is they that make it opaque to visible light, but infrared, microwave and radio radiation pass through them. The atmosphere of Venus is 90 times more massive than the Earth's, and also much hotter - its temperature is 740 K. The reason for this heating (more than on the surface of Mercury, which is closer to the Sun) lies in the greenhouse effect that occurs due to the high density of carbon dioxide - the main component atmosphere. The height of the Venusian atmosphere is about 250-350 km.

The atmosphere of Venus constantly and very rapidly circulates and rotates. Its rotation period is many times less than that of the planet itself - only 4 days. The wind speed is also huge - about 100 m / s in the upper layers, which is much more than on Earth. However, at low altitudes, the movement of winds is significantly weakened and reaches only about 1 m/s. Powerful anticyclones are formed at the poles of the planet - polar vortices having an S-shape.

Like the earth, the Venusian atmosphere consists of several layers. The lower layer - the troposphere - is the densest (99% of the total mass of the atmosphere) and extends to an average height of 65 km. Due to the high surface temperature, the lower part of this layer is the hottest in the atmosphere. The wind speed here is also low, but with increasing altitude, it increases, while the temperature and pressure decrease, and at an altitude of about 50 km they are already approaching Earth values. It is in the troposphere that the greatest circulation of clouds and winds is observed, and weather phenomena are observed - whirlwinds, hurricanes rushing at great speed, and even lightning that strikes here twice as often as on Earth.

Between the troposphere and the next layer - the mesosphere - there is a thin boundary - the tropopause. Here the conditions are most similar to those on the earth's surface: the temperature is from 20 to 37 ° C, and the pressure is approximately the same as at sea level.

The mesosphere occupies heights from 65 to 120 km. Its lower part has an almost constant temperature of 230 K. At an altitude of about 73 km, a cloud layer begins, and here the temperature of the mesosphere gradually decreases with a height of up to 165 K. At about an altitude of 95 km, the mesopause begins, and here the atmosphere again begins to heat up to values ​​of the order of 300 400 K. The temperature is the same for the overlying thermosphere, which extends to the upper boundaries of the atmosphere. It should be noted that, depending on the illumination of the surface of the planet by the Sun, the temperatures of the layers on the day and night sides differ significantly: for example, daytime values ​​for the thermosphere are about 300 K, and nighttime values ​​are only about 100 K. In addition, Venus also has an extended ionosphere at altitudes 100 - 300 km.

At an altitude of 100 km in the atmosphere of Venus there is an ozone layer. The mechanism of its formation is similar to that of the earth.

There is no own magnetic field on Venus, but there is an induced magnetosphere formed by streams of ionized particles of the solar wind, bringing with them the magnetic field of the star, frozen into the coronal matter. The lines of force of the induced magnetic field, as it were, flow around the planet. But due to the absence of its own field, the solar wind freely penetrates into its atmosphere, provoking its outflow through the magnetospheric tail.

The dense and opaque atmosphere practically does not allow sunlight to reach the surface of Venus, so its illumination is very low.

Structure

Photo from an interplanetary spacecraft

Information about the relief and internal structure of Venus has become available relatively recently thanks to the development of radar. Surveys of the planet in the radio range made it possible to create a map of its surface. It is known that more than 80% of the surface is filled with basaltic lava, and this suggests that the modern relief of Venus is formed mainly by volcanic eruptions. Indeed, there are a lot of volcanoes on the surface of the planet, especially small ones, with a diameter of about 20 kilometers and a height of 1.5 km. Whether any of them are active, at the moment it is impossible to say. There are much fewer craters on Venus than on other terrestrial planets, since the dense atmosphere prevents most celestial bodies from penetrating through it. In addition, spacecraft have discovered hills up to 11 km high on the surface of Venus, occupying about 10% of the entire area.

A single model of the internal structure of Venus has not been developed to this day. According to the most probable of them, the planet consists of a thin crust (about 15 km), a mantle more than 3000 km thick and a massive iron-nickel core in the center. The absence of a magnetic field on Venus can be explained by the absence of moving charged particles in the core. This means that the core of the planet is solid, since there is no movement of matter in it.

Observation

Since of all the planets Venus comes closest to the Earth and is therefore the most visible in the sky, it will not be difficult to observe it. It is visible to the naked eye even in the daytime, but at night or at dusk, Venus appears before the eyes as the brightest "star" in the celestial sphere with a magnitude of -4.4 m. Thanks to such an impressive brightness, the planet can be observed through a telescope even during the day.

Like Mercury, Venus does not move far from the Sun. The maximum angle of its deviation is 47 °. It is most convenient to observe it shortly before sunrise or immediately after sunset, when the Sun is still below the horizon and does not interfere with observation with its bright light, and the sky is still not dark enough for the planet to shine too brightly. Since the details on the disk of Venus are barely perceptible during observations, it is necessary to use a high-quality telescope. And even in it, most likely, only a grayish circle without any details. However, under good conditions and high-quality equipment, sometimes you can still see dark bizarre shapes and white spots formed by atmospheric clouds. Binoculars are useful only for finding Venus in the sky and its simplest observations.

The atmosphere on Venus was discovered by M.V. Lomonosov during its passage across the solar disk in 1761.

Venus, like the Moon and Mercury, has phases. This is due to the fact that its orbit is closer to the Sun than the Earth's, and therefore, when the planet is between the Earth and the Sun, only part of its disk is visible.

The tropopause zone in the atmosphere of Venus, due to conditions similar to those on Earth, is being considered for placement of research stations there and even for colonization.

Venus has no satellites, but for a long time there was a hypothesis according to which it was previously Mercury, but due to some external catastrophic impact, it left its gravitational field and became an independent planet. In addition, Venus has a quasi-satellite - an asteroid whose orbit of rotation around the Sun is such that it does not get out of the influence of the planet for a long time.

In June 2012, the last transit of Venus across the solar disk in this century took place, which was completely observed in the Pacific Ocean and almost throughout Russia. The last passage was observed in 2004, and earlier ones in the 19th century.

Because of the many similarities to our planet, life on Venus was considered possible for a long time. But since it became known about the composition of its atmosphere, the greenhouse effect and other climatic conditions, it is obvious that such terrestrial life on this planet is impossible.

Venus is one of the candidates for terraforming - changing the climate, temperature and other conditions on the planet in order to make it habitable for terrestrial organisms. First of all, for this it will be necessary to deliver enough water to Venus to start the process of photosynthesis. It is also necessary to make the temperature on the surface significantly lower. To do this, it is necessary to negate the greenhouse effect by converting carbon dioxide into oxygen, which could be handled by cyanobacteria, which would need to be sprayed into the atmosphere.