Simple ways to find Venus in the sky. How to observe Mercury and Venus Is it possible to see Venus from the earth

Mercury is called "elusive" because it is difficult to observe. This planet, closest to the Sun, often hides in its rays, and in our sky does not move far from the Sun - at most 28 degrees, since the orbit of Mercury is located inside the Earth. Mercury is always in the sky, either in the same constellation as the Sun, or in a neighboring one. Mercury is usually seen against the background of dawn and is difficult to find in a bright sky. The most favorable time for observing Mercury comes during the period when it is as far away from the Sun as possible in the sky.

Austria On the same days - on the border of the constellations Sagittarius and Capricorn - Mercury is visible next to Venus - it is also bright (comparable in brightness to the brightest stars in the sky), but the evening dawn may turn out to be brighter than it and it will most likely be possible to find Mercury only through binoculars - find Venus with your eye, point your binoculars at it and Mercury will be in the same field of view. This is a rather rare event and must be seen. The convergence of Venus with Mercury will last until mid-January 2015.

USA The angular distance of a planet from the Sun is called elongation. If the planet is far from the Sun to the east, this is the eastern elongation, if to the west, it is the western one. With eastern elongation, Mercury is visible in the west, low above the horizon in the rays of evening dawn, shortly after sunset, and sets some time after it. In western elongation, Mercury is visible in the morning in the east against the background of dawn, shortly before sunrise. This couple is also visible from the territory of Russia. Astronomers write. that they should be visible within an hour and they set at about seven in the evening on January 15, Mercury will be in the greatest eastern elongation, moving away from the Sun by 19 degrees. And the days coming to this date are the most favorable for observing it. After sunset, Mercury will be above the horizon for almost two hours. As a bright star, it will be visible in the southwest in the constellation Capricorn, low above the horizon. Venus can easily help you find it. This brightest planet, attracting attention with its brilliance, shines in the evenings over the western horizon. The bright star to the right of it is Mercury.

Japan After January 16, 2015, the paths of Venus and Mercury in the sky will go their separate ways. Mercury will begin to return to the Sun, describing a loop in the celestial sphere, and Venus will continue to move away from the daylight and the duration of its visibility will increase every day.

The visibility and location of the planets in the sky during the month.

June, the "lightest" month, is not very favorable for astronomical observations. If in the south the nights are simply short, then in temperate latitudes the period of white nights begins altogether. Bright planets, the Sun and the Moon remain almost the only available objects for observation.

All four bright planets can be seen in the June sky this year. Jupiter is visible in the first half of the month in the evenings in the west, beautiful Venus throughout June - in the mornings in the east. In the evenings in the south and southwest, you can observe Mars and Saturn. These two planets are the most convenient for observations in June.

But we will start our review with Mercury, the planet closest to the Sun.

Mercury

Mercury minutes before it is covered by the Moon in the daytime sky of Sochi on June 26, 2014.

At the beginning of June, the period of evening visibility of Mercury ends. The planet closest to the Sun could be observed in the early days of the month low in the northwest for about half an hour after sunset, and only in the south, outside the zone of white nights. Almost all of June, Mercury is in the sky near our daytime star and therefore is inaccessible for observations. On June 19, the planet enters into a lower conjunction with the Sun, that is, it will pass between the Earth and the Sun, after which it moves to the morning sky.

On June 26, Mercury, being in the sky only 10 ° from the Sun, will be covered by the Moon. This interesting phenomenon will be observed in the Atlantic, America and Europe, in particular, in the Crimea and the Black Sea coast of the Caucasus. Coverage will begin at around 5 pm when the Moon and Sun are in the western sky.

The brightness of Mercury will be about 2.5m, which, in principle, allows you to see the planet against a blue sky background in a good amateur telescope. However, be extremely careful! Do not forget that the coating will occur near the Sun and the rays of the star can accidentally hit the eyepiece and damage your eyesight! We would recommend observing this phenomenon only to experienced amateurs. For our part, we will try to publish interesting photos of the coverage, if any appear on the Internet.

Venus

Haven't seen Venus this summer yet? In early June, the Morning Star rises about an hour before sunrise over the eastern (more precisely, over the northeastern-eastern) part of the horizon.

However, the period of visibility of Venus is rather arbitrary: in Ukraine, the Crimea and the Caucasus, the planet is currently visible for almost 1.5 hours, appearing in the dark sky. At the latitude of Moscow, the period of visibility of Venus does not even reach an hour. Farther north, in view of the white nights - and even less. In this case, the planet rises against the background of dawn. But you can still find it in St. Petersburg because of the great brightness of the planet (during June it stays at about -4m). Note that at sunrise, Venus, which is actually white, can be red, orange, and deep yellow, confusing a beginner. In this case, we are faced with a typical reddening of space objects near the horizon due to dust floating in the Earth's atmosphere.

What will happen in the sky with Venus during the month? I must say that throughout June the planet has a direct motion (that is, it moves against the background of stars in the same direction with the Sun, from west to east), moving along the constellation Aries. Venus is gradually catching up with the star in the sky, but in June the distance decreases slightly - from 37 to 30 degrees. At the same time, the position of the planet's rising point shifts slightly to the north.

30 degrees from the Sun is a very comfortable distance for observing such a bright planet in the predawn sky. However, in temperate latitudes and in the north, white nights intervene, which makes it somewhat difficult to observe. But in this case, as we said above, Venus can be quite easily seen with the naked eye, not to mention observations through a telescope or binoculars. Before the sun rises, the planet manages to rise into the sky at the latitude of Moscow by about 10 °, at the latitude of Sochi - 15 ° above the horizon.

Perhaps it is after sunrise that the June telescope observations of Venus will be most interesting and productive. Already in the morning, the planet rises high enough above the horizon so that atmospheric turbulence does not greatly distort the picture in the eyepiece, and the low contrast between the blinding white Venus and the blue sky background often allows you to notice much more detail in the planet's cloud cover than usual.

During June, the apparent dimensions decrease from 14 to 12 arc seconds, and the phase increases from 0.77 to 0.86. (The planet, following a smaller orbit, overtook the Earth and is now moving away from it, and after a few months it will hide behind the Sun.)

Venus and the Moon in the morning sky on June 24. The dimensions of the Moon are magnified 4 times for clarity.

I must say that during the day it is quite possible to see Venus with the naked eye. To do this, it is enough to isolate oneself from the bright Sun and consider a section of the sky 30 ° to the right of the star. In the first half of the day, Venus will be slightly higher than the Sun, in the second, respectively, lower. Finally, on June 24, an excellent reference point for searching for Venus both before sunrise and in the daytime sky will be the “aging” Moon, whose narrow crescent will approach the planet up to 3.5 °.

Mars

2 months have passed since the April opposition of Mars. The brightness and apparent size of the Red Planet have significantly decreased and continue to decrease rapidly. However, in June, Mars remains one of the most visible celestial bodies in the evening and at night.

The whole month the planet is in the constellation Virgo, moving against the background of stars in the same direction with the Sun and gradually approaching Spica, the main star of the constellation Virgo. Mars appears in the evening twilight in the southwest at 25 ° above the horizon (at the latitude of Moscow). The planet can be distinguished from stars by its characteristic pinkish color and even radiance (stars usually flicker noticeably).

At the beginning of June, the visibility of Mars is about 4 hours, at the end - already only 2 hours. The planet's brightness decreases from -0.5m to 0.0m, the diameter of the visible disk - from 11.9 ″ to 9.5 ″. In a good amateur telescope with a lens of 120 mm and higher, many interesting details can be found on the planet's disk - polar caps, dark and light areas, areas with various shades of yellow, red and even blue. And in modern digital photographs, the Mysterious Planet appears very effectively today.

Planet Mars, photographed on May 7, 2014. The image clearly shows the northern polar cap, dark areas of the Chryse area and bright cirrus clouds.

Jupiter

Saturn, Moon, Mars and Jupiter on the evening of June 8th. Jupiter in the evenings in the first half of June is visible in the rays of the evening dawn low in the northwest.

Shining in our sky for almost a year, Jupiter ends the period of evening visibility in June. The planet moves in the same direction with the Sun, but being farther from us than the daylight, it moves slower than the Sun against the background of stars. At the end of July, the Sun will catch up with Jupiter and the planet will again, like last year, move to the evening sky, where on August 18 a remarkable rapprochement with Venus will take place.

In the first half of June, Jupiter can be observed for about 2 hours in the evening twilight in the northwest (90 ° to the right of Mars); at the end of the month, the planet is actually hiding in the rays of the sun.

Despite the fact that Jupiter is currently located near the point of its orbit farthest from the Earth, the planet is so large that its brightness and size have not decreased too much compared to the winter period. In June, Jupiter's brightness is in the region of -1.9m, and the diameter of the visible disk is about 32 ″. The planet is still perfectly visible even with small telescopes; her observations will be much more hindered by the low position above the horizon and the bright background of the sky in temperate latitudes than the distance from the Earth.

Saturn

The Moon and Saturn approach at midnight on June 11, 2014. Note that Saturn, Mars and the bright star Arcturus form an almost isosceles triangle in the sky in June.

The position of Saturn in the sky makes this planet the most convenient to observe in June 2014. Being in the constellation Libra for the whole month, the ringed giant appears with the onset of dusk in the south at an altitude of 15-20 degrees above the horizon, depending on the latitude of observation. In the south of Russia, Ukraine, Kazakhstan, the visibility of Saturn will be about 6 hours, in temperate latitudes the planet will be visible throughout the entire short night.

In terms of magnitude (0.4m), Saturn is comparable to the brightest stars, but this may not be enough for a beginner to confidently identify the planet in the bright night sky of June. Especially for beginner astronomy lovers, we will inform you that in the evening Saturn can be found 30 ° (about 3-4 fists of an outstretched hand) east of the reddish and brighter Mars. When searching, it is important not to confuse Mars with the star Arcturus, which is also reddish and has approximately the same brightness as Mars. In general, Mars, Arcturus and Saturn form an isosceles triangle in the June sky, at the base of which there are two planets. The easiest way to find the planet will be on the night of June 10-11. At this time, next to Saturn (only 1.5 ° south of the planet), the Moon will be in a phase close to the full moon.

Saturn's color is yellow. Even in a small telescope, one can see the disk of the planet flattened to the poles and the luxurious rings of the planet, open at 20 °. The apparent dimensions of the planet are 18 ″, and the rings are 40 × 15 ″. In a telescope with a lens of 100 mm or more, you can try to see the Cassini Slit in the rings of the planet. Even in smaller instruments, you can see the largest moon of Saturn, Titan, in the form of an asterisk 8.4m.

Uranus and Neptune

The last planets in our review are Uranus and Neptune. The distant giants are too weak to be observed with the naked eye (only Uranus in moments of opposition can be seen at the limit of visibility on a moonless night). And in most amateur telescopes, they look at best like tiny greenish-blue discs without any details.

Now both Uranus and Neptune are in the morning sky in the constellations of Pisces and Aquarius, respectively. The visibility of Uranus is about 1 hour in June at the beginning of the month and rises to 2 hours at the end. The brightness of the planet is 6.0m, the apparent size of the planet is 3.4 ″; to see the disc, you need a telescope with a lens of at least 80 mm and a magnification of 80 × or higher. Note that it is almost impossible to observe the planet north of Moscow due to the white nights.

To an even greater extent, the latter also applies to Neptune, which, although it rises almost an hour earlier than Uranus, has a magnitude of only 8m. Like Uranus, Neptune moves across the sky in the same direction as the Sun. It can be found near the sigma star Aquarius (magnitude 4.8m). To see the planet's disk, you need a more serious instrument: a telescope with a 100-120 mm objective lens and a magnification of over 100 ×.

Let us repeat that the search and observation of these planets, due to their remoteness from the Earth, have, at best, only cognitive value for amateurs.

Let's summarize. In June, all the planets are visible in the sky, except for Mercury, which on the 19th is in the lower conjunction with the Sun. The most favorable conditions will be for the observation of Saturn and Mars. These two planets appear in the sky at dusk in the south and southwest, respectively. The planets are located at an altitude of about 20 ° above the horizon and are visible for 6 and 4 hours, respectively. In temperate latitudes, Saturn can be observed throughout the short night.

Venus is visible in the morning in the east for about an hour before sunrise. The brilliance of the planet makes it possible to observe it during the day, both with a telescope and with the naked eye. Jupiter can still be found in the evenings in the northwest, in the rays of the evening dawn. Its visibility is rapidly decreasing, and at the end of the month the planet will hide in the rays of the Sun.

Planet venus

General information about the planet Venus. Sister of the Earth

Fig. 1 Venus. Snapshot of the MESSENGER apparatus dated January 14, 2008. Credit: NASA / Johns Hopkins University Applied Physics Laboratory / Carnegie Institution of Washington

Venus is the second planet from the Sun, very similar in size, gravity and composition to our Earth. At the same time, it is the brightest object in the sky after the Sun and Moon, reaching a magnitude of -4.4.

The planet Venus has been studied very well, because more than a dozen spacecraft have visited it, but astronomers still have some questions. Here are just a few of them:

The first of the questions concerns the rotation of Venus: its angular velocity is just such that during the lower conjunction, Venus is facing the Earth all the time by the same side. The reasons for this consistency between the rotation of Venus and the orbital motion of the Earth are not yet clear ...

The second question is the source of motion of the atmosphere of Venus, which is a continuous giant vortex. Moreover, this movement is very powerful and is characterized by amazing constancy. What forces create an atmospheric vortex of this size is unknown?

And the last, third, question - is there life on the planet Venus? The fact is that at an altitude of several tens of kilometers in the cloudy layer of Venus, conditions are observed that are quite suitable for the life of organisms: not very high temperature, suitable pressure, etc.

It should be noted that there were much more questions related to Venus just half a century ago. Astronomers did not know anything about the planet's surface, did not know the composition of its amazing atmosphere, did not know the properties of its magnetosphere, and much more. But they knew how to find Venus in the night sky, observe its phases associated with the movement of the planet around the Sun, etc. Read about how to conduct such observations below.

Observing the planet Venus from Earth

Fig. 2 View of the planet Venus from Earth. Credit: Carol Lakomiak

Since Venus is closer to the Sun than the Earth, it never seems too far from it: the maximum angle between it and the Sun is 47.8 °. Due to these features of the position in the Earth's sky, Venus reaches its maximum brightness shortly before sunrise or some time after sunset. During 585 days, the periods of its evening and morning visibility alternate: at the beginning of the period, Venus is visible only in the morning, then 263 days later, it comes very close to the Sun, and its brightness does not allow seeing the planet for 50 days; then the period of evening visibility of Venus begins, lasting 263 days, until the planet again disappears for 8 days, finding itself between the Earth and the Sun. After that, the alternation of visibility is repeated in the same order.

It is easy to recognize the planet Venus, because in the night sky it is the brightest luminary after the Sun and the Moon, reaching a maximum of -4.4 magnitude. A distinctive feature of the planet is its even white color.

Fig. 3 Phase change of Venus. Credit: website

When observing Venus, even with a small telescope, one can see how the illumination of its disk changes over time, i.e. there is a phase change, which was first observed by Galileo Galilei in 1610. At the closest approach to our planet, only a small part of Venus remains consecrated and it takes the form of a thin sickle. The orbit of Venus at this time is at an angle of 3.4 ° to the orbit of the Earth, so it usually passes just above or just below the Sun at a distance of up to eighteen solar diameters.

But sometimes there is a situation in which the planet Venus is located approximately on the same line between the Sun and the Earth, and then you can see an extremely rare astronomical phenomenon - the passage of Venus across the disk of the Sun, in which the planet takes the form of a small dark "speck" with a diameter of 1/30 solar.

Fig. 4 The passage of Venus across the disk of the Sun. Snapshot of NASA's TRACE satellite from August 6, 2004. Credit: NASA

This phenomenon occurs approximately 4 times in 243 years: first, 2 winter passages are observed with a frequency of 8 years, then an interval of 121.5 years lasts, and 2 more, this time summer, passages occur with the same frequency of 8 years. The winter transits of Venus can then be observed only after 105.8 years.

It should be noted that if the duration of the 243-year cycle is a relatively constant value, then the frequency between winter and summer passages within it changes due to small discrepancies in the periods of the return of the planets to the points of their orbits' connection.

So, until 1518, the internal sequence of Venus's transits looked like "8-113.5-121.5", and before 546 there were 8 transits, the intervals between which were 121.5 years. The current sequence will remain until 2846, after which it will be replaced by another one: "105.5-129.5-8".

The last transit of the planet Venus, lasting 6 hours, was observed on June 8, 2004, the next one will take place on June 6, 2012. Then there will be a break, the end of which will only be in December 2117.

History of the exploration of the planet Venus

fig. 5 Ruins of an observatory in the city of Chichen Itza (Mexico). Source: wikipedia.org.

The planet Venus, along with Mercury, Mars, Jupiter and Saturn, was known to people of the Neolithic era (new Stone Age). The planet was well known by the ancient Greeks, Egyptians, Chinese, the inhabitants of Babylon and Central America, the tribes of Northern Australia. But, due to the peculiarities of observing Venus only in the morning or in the evening, the ancient astronomers believed that they saw completely different celestial objects, therefore they called the morning Venus by one name, and the evening one by another. So, the Greeks gave the evening Venus the name Vesper, and the morning - Phosphorus. The ancient Egyptians also gave the planet two names: Tayoumutiri - morning Venus and Oueyte - evening. The Maya Indians called Venus Noh Ek - "Great Star" or Xux Ek - "Star of the Wasp" and were able to calculate its synodic period.

The first people to understand that morning and evening Venus are one and the same planet were the Greek Pythagoreans; a little later, another ancient Greek, Heraclides of Pontus, suggested that Venus and Mercury revolve around the Sun, not the Earth. Around the same time, the Greeks gave the planet the name of the goddess of love and beauty Aphrodite.

But the planet received the name "Venus" familiar to modern people from the Romans, who named it after the patron goddess of the entire Roman people, who occupied the same place in Roman mythology as Aphrodite did in Greek.

As you can see, ancient astronomers only observed the planet, simultaneously calculating synodic periods of rotation and drawing up maps of the starry sky. Attempts have also been made to calculate the distance from the Earth to the Sun by observing Venus. For this, it is necessary, when the planet passes directly between the Sun and the Earth, using the parallax method, to measure the insignificant differences in the time of the beginning or end of the passage at two sufficiently distant points of our planet. The distance between the points is further used as the length of the base to determine the distances to the Sun and Venus by the triangulation method.

Historians do not know when astronomers first observed the passage of the planet Venus across the disk of the Sun, but they do know the name of the person who first predicted such a passage. It was the German astronomer Johannes Kepler, who predicted the passage of 1631. However, in the predicted year, due to some inaccuracy of the Keplerian forecast, no one observed the passage in Europe ...

Fig. 6 Jerome Horrocks observes the passage of the planet Venus across the disk of the Sun. Source: wikipedia.org.

But another astronomer, Jerome Horrocks, having refined Kepler's calculations, found out the exact repetition periods of the passages, and on December 4, 1639, from his home in Mach Hoole in England, he was able to personally see the passage of Venus across the disk of the Sun.

Using a simple telescope, Horrocks projected the solar disk onto a board, where it was safe for the observer's eyes to see everything that was happening against the background of the solar disk. And at 15 hours 15 minutes, just half an hour before sunset, Horrocks finally saw the predicted passage. With the help of the observations, the English astronomer tried to estimate the distance from the Earth to the Sun, which turned out to be equal to 95.6 million km.

In 1667, Giovanni Domenico Cassini made the first attempt to determine the period of rotation of Venus around its axis. The value he received was very far from the real one and was 23 hours and 21 minutes. This was due to the fact that Venus had to be observed only once a day and only for several hours. Directing his telescope to the planet for several days and seeing the same picture all the time, Cassini came to the conclusion that the planet Venus has made a complete revolution around its axis.

After the observations of Horrocks and Cassini, knowing Kepler's calculations, astronomers around the world were looking forward to the next opportunity to observe the transit of Venus. And such an opportunity presented itself to them in 1761. Among the astronomers who carried out the observations was our Russian scientist Mikhail Vasilyevich Lomonosov, who discovered when the planet entered the solar disk, as well as when it left it, a bright ring around the dark disk of Venus. Lomonosov explained the observed phenomenon, later named after him ("Lomonosov's phenomenon"), by the presence of an atmosphere on Venus, in which the sun's rays were refracted.

After 8 years, the observations were continued by the English astronomer William Herschel and the German astronomer Johann Schroeter, again "discovering" the Venusian atmosphere.

In the 60s of the XIX century, astronomers began to make attempts to find out the composition of the discovered atmosphere of Venus, and first of all, to determine the presence of oxygen and water vapor in it using spectral analysis. However, neither oxygen nor water vapor was found. Some time later, already in the twentieth century, attempts to find the "gases of life" were resumed: observations and research were carried out by A. A. Belopolsky in Pulkovo (Russia) and Vesto Melvin Slifer in Flagstaff (USA).

In the same XIX century. the Italian astronomer Giovanni Schiaparelli again tried to establish the period of rotation of Venus around its axis. Assuming that the circulation of Venus to the Sun is always associated with its very slow rotation, he set the period of its rotation around the axis as equal to 225 days, which was 18 days less than the real one.

fig. 7 Mount Wilson Observatory. Credit: MWOA

In 1923, Edison Pettit and Seth Nicholson at the Mount Wilson Observatory on Mount Wilson in California (USA) began measuring the temperature of the upper clouds of Venus, which was subsequently carried out by many scientists. Nine years later, American astronomers W. Adams and T. Denham at the same observatory recorded three bands in the spectrum of Venus belonging to carbon dioxide (CO 2). The intensity of the bands made it possible to conclude that the amount of this gas in the atmosphere of Venus is many times higher than its content in the atmosphere of the Earth. No other gases were found in the Venusian atmosphere.

In 1955, William Sinton and John Strong (USA) measured the temperature of the cloud layer of Venus, which turned out to be -40 ° С, and even lower near the planet's poles.

In addition to the Americans, Soviet scientists N.P. Barabashov, V.V. Sharonov and V.I. Ezersky, French astronomer B. Lyot. Their studies, as well as the theory of light scattering by dense planetary atmospheres, developed by Sobolev, indicated that the size of the particles of Venus' clouds is about one micrometer. Scientists had only to find out the nature of these particles and study in more detail the entire thickness of the cloud layer of Venus, and not just its upper boundary. And for this it was necessary to send interplanetary stations to the planet, which were subsequently created by scientists and engineers of the USSR and the USA.

The first spacecraft launched to the planet Venus was "Venus-1". This event took place on February 12, 1961. However, after some time, communication with the apparatus was lost and Venera-1 entered the orbit of the Sun's satellite.

fig. 8 "Venus-4". Credit: NSSDC

fig. 9 "Venus-5". Credit: NSSDC

The next attempt was also unsuccessful: the Venera-2 spacecraft flew at a distance of 24 thousand km. from the planet. Only Venera-3, launched by the Soviet Union in 1965, was able to come relatively close to the planet and even land on its surface, which was facilitated by a specially designed descent vehicle. But due to the failure of the control system of the station, no data about Venus was received.

2 years later, on June 12, 1967, Venera-4 set off to the planet, also equipped with a descent vehicle, the purpose of which was to study the physical properties and chemical composition of the Venusian atmosphere using 2 resistance thermometers, a barometric sensor, an ionization atmospheric density meter and 11 cartridges. gas analyzers. The device fulfilled its purpose, having established the presence of a huge amount of carbon dioxide, a weak magnetic field surrounding the planet and the absence of radiation belts.

In 1969, with an interval of only 5 days, 2 interplanetary stations with serial numbers 5 and 6 went to Venus at once.

Their descent vehicles, equipped with radio transmitters, radio altimeters and other scientific equipment, transmitted information about the pressure, temperature, density and chemical composition of the atmosphere during the descent. It turned out that the pressure of the Venusian atmosphere reaches 27 atmospheres; it was not possible to find out whether it could exceed the indicated value: the descent vehicles for higher pressure were simply not calculated. The temperature of the Venusian atmosphere during the descent of the spacecraft ranged from 25 ° to 320 ° C. The atmosphere was dominated by carbon dioxide with a small amount of nitrogen, oxygen and an admixture of water vapor.

Fig. 10 "Mariner-2". Credit: NASA / JPL

In addition to the spacecraft of the Soviet Union, the American spacecraft of the "Mariner" series were engaged in the study of the planet Venus, the first of which with serial number 2 (number 1 crashed at the start) flew past the planet in December 1962, having determined the temperature of its surface. Similarly, another American spacecraft, Mariner 5, explored Venus while flying past the planet in 1967. Carrying out its program the fifth by number "Mariner" confirmed the prevalence of carbon dioxide in the atmosphere of Venus, found out that the pressure in the thickness of this atmosphere can reach 100 atmospheres, and the temperature - 400 ° C.

It should be noted that the study of the planet Venus in the 60s. came from the Earth. So, using radar methods, American and Soviet astronomers have established that the rotation of Venus is the opposite, and the rotation period of Venus is ~ 243 days.

On December 15, 1970, the Venera-7 spacecraft first reached the planet's surface and, having worked on it for 23 minutes, transmitted data on the composition of the atmosphere, the temperature of its various layers, as well as pressure, which, according to the results of measurements, was equal to 90 atmospheres.

A year and a half later, in July 1972, another Soviet spacecraft landed on the surface of Venus.

With the help of scientific equipment installed on the descent vehicle, the illumination on the surface of Venus was measured, equal to 350 ± 150 lux (as on Earth on a cloudy day), and the density of surface rocks, equal to 1.4 g / cm 3. It was found that the clouds of Venus lie at an altitude of 48 to 70 km, have a layered structure and consist of droplets of 80% sulfuric acid.

In February 1974, Mariner-10 flew past Venus, photographing its cloud cover for 8 days in order to study the dynamics of the atmosphere. Based on the images obtained, it was possible to determine the rotation period of the Venusian cloud layer equal to 4 days. It also turned out that this rotation occurs clockwise when viewed from the north pole of the planet.

Fig.11 The Venera-10 descent vehicle. Credit: NSSDC

A few months later, in October 1974, Soviet spacecraft with serial numbers 9 and 10 landed on the surface of Venus. After landing 2200 km from each other, they transmitted to Earth the first panoramas of the surface at the landing sites. Within an hour, the descent vehicles transmitted scientific information from the surface to spacecraft, which were transferred to the orbits of artificial satellites of Venus and relayed it to Earth.

It should be noted that after the flights of Venus-9 and 10, the Soviet Union launched all spacecraft of this series in pairs: first, one spacecraft was sent to the planet, then with a minimum time interval - another.

So, in September 1978, Venera-11 and Venera-12 went to Venus. On December 25 of the same year, their descent vehicles reached the planet's surface, taking a number of photographs and transmitting some of them to Earth. Partly because one of the descent vehicles did not open the protective covers of the chamber.

During the descent of the spacecraft, electrical discharges were recorded in the atmosphere of Venus, and extremely powerful and frequent. So, one of the devices detected 25 discharges per second, the other - about a thousand, and one of the peals of thunder lasted 15 minutes. According to astronomers, electrical discharges were associated with active volcanic activity in the places of descent of spacecraft.

At about the same time, the study of Venus was already conducted by the spacecraft of the American series - "Pioneer-Venera-1", launched on May 20, 1978.

Having entered a 24-hour elliptical orbit around the planet on December 4, the device carried out radar mapping of the surface for a year and a half, studied the magnetosphere, ionosphere and cloud structure of Venus.

fig. 12 "Pioneer-Venus-1". Credit: NSSDC

Following the first "pioneer", the second went to Venus. It happened on August 8, 1978. On November 16, the first and largest of the descent vehicles separated from the vehicle, 4 days later, 3 other descent vehicles separated. On December 9, all four modules entered the planet's atmosphere.

Based on the results of the study of the Pioneer-Venera-2 descent vehicles, the composition of the Venus atmosphere was determined, as a result of which it was found that the concentration of argon-36 and argon-38 in it is 50-500 times higher than the concentration of these gases in the Earth's atmosphere. The atmosphere is composed primarily of carbon dioxide, with small amounts of nitrogen and other gases. Under the very clouds of the planet, traces of water vapor and a higher than anticipated concentration of molecular oxygen were found.

The very same cloud layer, as it turned out, consists of at least 3 well-defined layers.

The upper one, lying at an altitude of 65-70 km, contains drops of concentrated sulfuric acid. The other 2 layers are approximately the same in composition, with the only difference that larger sulfur particles prevail in the lowest of the layers. At altitudes below 30 km. Venus's atmosphere is relatively transparent.

During the descent, the devices carried out temperature measurements, which confirmed the colossal greenhouse effect reigning on Venus. So, if at altitudes of about 100 km the temperature was -93 ° C, then at the upper boundary of the clouds it was -40 ° C, and then continued to increase, reaching 470 ° C at the very surface ...

In October-November 1981, with an interval of 5 days, "Venera-13" and "Venera-14" set off, whose descent vehicles in March, already on the 82nd, reached the planet's surface, transmitting panoramic images of landing sites to Earth. on which the yellow-green Venusian sky was visible, and after examining the composition of the Venusian soil, in which they found: silica (up to 50% of the total mass of the soil), aluminum alum (16%), magnesium oxides (11%), iron, calcium and others elements. In addition, with the help of a sound recording device installed on "Venus-13", scientists for the first time heard the sounds of another planet, namely, thunderclaps.

fig.13 Surface of the planet Venus. A snapshot of the Venera-13 spacecraft dated March 1, 1982. Credit: NSSDC

On June 2, 1983, the AMS (automatic interplanetary station) "Venera-15" went to the planet Venus, which on October 10 of the same year entered polar orbit around the planet. On October 14, Venera-16 was launched into orbit, launched 5 days later. Both stations were designed to explore the Venusian relief using radars on board. Having worked together for more than eight months, the stations obtained an image of the planet's surface within a vast area: from the north pole to ~ 30 ° north latitude. As a result of processing these data, a detailed map of the northern hemisphere of Venus on 27 sheets was compiled and the first atlas of the planet's relief was published, which, however, covered only 25% of its surface. Also, based on the materials of the spacecraft surveys, Soviet and American cartographers, within the framework of the first international project on extraterrestrial cartography, held under the auspices of the Academy of Sciences and NASA, jointly created a series of three survey maps of northern Venus. The presentation of this series of maps, entitled "Magellan Flight Planning Kit", took place in the summer of 1989 at the International Geological Congress in Washington.

Fig.14 Descent module АМС "Vega-2". Credit: NSSDC

After "Venus" the study of the planet was continued by the Soviet AMS of the "Vega" series. There were two of these vehicles: "Vega-1" and "Vega-2", which, with a difference of 6 days, were launched to Venus in 1984. Six months later, the vehicles came close to the planet, then the descent modules separated from them, which, having entered the atmosphere, also divided into landing modules and balloon probes.

2 balloon probes, after filling the shells of their parachutes with helium, drifted at an altitude of about 54 km in different hemispheres of the planet, and transmitted data for two days, having flown about 12 thousand km during this time. The average speed at which the probes flew this path was 250 km / h, aided by the powerful global rotation of the Venusian atmosphere.

The data from the probes showed the presence of very active processes in the cloud layer, characterized by powerful ascending and descending currents.

When the probe "Vega-2" flew in the area of ​​Aphrodite over the top 5 km in height, it fell into an air hole, sharply descending by 1.5 km. Both probes also detected lightning discharges.

The lander carried out a study of the cloud layer and the chemical composition of the atmosphere while they were descending, after which, after making a soft landing on the Rusalka Plain, they began to analyze the soil by measuring X-ray fluorescence spectra. At both points where the modules landed, they found rocks with relatively low concentrations of natural radioactive elements.

In 1990, while making gravity assist maneuvers, the Galileo (Galileo) spacecraft flew past Venus, from which the NIMS infrared spectrometer was taken, as a result of which it turned out that at wavelengths 1.1, 1.18 and 1, The 02 µm signal correlates with the surface topography, that is, for the corresponding frequencies there are “windows” through which the planet's surface is visible.

fig.15 Loading of the interplanetary station "Magellan" into the cargo hold of the spacecraft "Atlantis". Credit: JPL

A year earlier, on May 4, 1989, NASA's Magellan interplanetary station departed for the planet Venus, which, having worked until October 1994, received photographs of almost the entire surface of the planet, simultaneously carrying out a number of experiments.

The survey was carried out until September 1992, covering 98% of the planet's surface. Having entered an elongated polar orbit around Venus in August 1990 with heights from 295 to 8500 km and an orbital period of 195 minutes, the spacecraft at each approach to the planet mapped a narrow strip 17 to 28 km wide and about 70 thousand km long. There were 1800 such bands in total.

Since the Magellan repeatedly filmed many areas from different angles, which made it possible to compile a three-dimensional model of the surface, as well as to investigate possible changes in the landscape. The stereo image was obtained for 22% of the Venusian surface. In addition, there were compiled: a map of the heights of the surface of Venus, obtained using an altimeter (altimeter) and a map of the electrical conductivity of its rocks.

According to the results of the images, in which details up to 500 m in size were easily distinguished, it was found that the surface of the planet Venus is mainly occupied by hilly plains, and is relatively young by geological standards - about 800 million years. There are relatively few meteorite craters on the surface, but traces of volcanic activity are often found.

From September 1992 to May 1993, Magellan studied the gravitational field of Venus. During this period, he did not carry out surface radar, but broadcast a constant radio signal to the Earth. By changing the frequency of the signal, it was possible to determine the slightest changes in the speed of the vehicle (the so-called Doppler effect), which made it possible to reveal all the features of the gravitational field of the planet.

In May, "Magellan" began its first experiment: the practical application of the technology of atmospheric braking, to clarify the previously obtained information about the gravitational field of Venus. To do this, its lower orbital point was slightly lowered so that the device touches the upper atmosphere and changes the orbital parameters without consuming fuel. In August, the orbit of "Magellan" ran at altitudes of 180-540 km, having a period of 94 minutes. Based on the results of all measurements, a "gravity map" was compiled, covering 95% of the surface of Venus.

Finally, in September 1994, a final experiment was carried out, the purpose of which was to study the upper atmosphere. The craft's solar panels were deployed like the blades of a windmill, and the Magellan's orbit was lowered. This made it possible to obtain information about the behavior of molecules in the uppermost layers of the atmosphere. On October 11, the orbit was lowered for the last time, and on October 12, when entering the dense layers of the atmosphere, communication with the spacecraft was lost.

During its work, "Magellan" made several thousand orbits around Venus, three times taking pictures of the planet using side-looking radars.

Fig.16 Cylindrical map of the surface of the planet Venus, compiled from images of the interplanetary station "Magellan". Credit: NASA / JPL

After the flight of "Magellan" for a long 11 years in the history of the study of Venus by spacecraft, there was a break. The program of interplanetary research of the Soviet Union was curtailed, the Americans switched to other planets, primarily to the gas giants: Jupiter and Saturn. And only on November 9, 2005, the European Space Agency (ESA) sent to Venus a new generation spacecraft Venus Express, created on the same platform as Mars Express launched 2 years earlier.

fig. 17 Venus Express. Credit: ESA

5 months after launch, on April 11, 2006, the device arrived at the planet Venus, soon entering a highly elongated elliptical orbit and becoming its artificial satellite. At the most distant point of the orbit from the center of the planet (apocenter), Venus Express went 220 thousand kilometers from Venus, and in the closest (pericenter) it passed at an altitude of only 250 kilometers from the planet's surface.

After a while, thanks to subtle orbital corrections, the Venus Express periapsis was lowered even lower, which allowed the vehicle to enter the uppermost layers of the atmosphere, and, due to aerodynamic friction, over and over again slightly, but surely, slowing down the speed to lower the apocenter height. As a result, the parameters of the orbit, which became circumpolar, acquired the following parameters: the height of the apocenter is 66,000 kilometers, the height of the pericenter is 250 kilometers, the orbital period of the apparatus is 24 hours.

The parameters of the near-polar working orbit of "Venus Express" were not chosen by chance: so the period of circulation of 24 hours is convenient for regular communication with the Earth: after approaching the planet, the device collects scientific information, and after moving away from it, it conducts an 8-hour communication session, transmitting one time before 250 MB of information. Another important feature of the orbit is its perpendicularity to the equator of Venus, which is why the device has the ability to explore in detail the polar regions of the planet.

When entering a near-polar orbit, an annoying nuisance happened to the device: the PFS spectrometer, intended for studying the chemical composition of the atmosphere, was out of order, or rather turned off. As it turned out, the mirror was jammed, which was supposed to switch the "gaze" of the device from the reference source (on board the probe) to the planet. After several attempts to work around the failure, the engineers were able to rotate the mirror 30 degrees, but this was not enough for the device to work, and in the end it had to be turned off.

On April 12, the device for the first time took pictures of the previously not photographed south pole of Venus. These first photographs, taken with the VIRTIS spectrometer from an altitude of 206,452 kilometers above the surface, revealed a dark funnel, similar to a similar formation above the planet's north pole.

fig. 18 Clouds over the surface of Venus. Credit: ESA

On April 24, the VMC camera took a series of ultraviolet images of the Venusian cloud cover, which is associated with a significant - 50 percent, absorption of this radiation in the planet's atmosphere. After snapping to the grid, a mosaic image was obtained, covering a significant area of ​​the clouds. When analyzing this image, low-contrast ribbon structures were identified, which are the result of the action of strong winds.

A month after arrival - on May 6 at 23 hours 49 minutes Moscow time (19:49 UTC), Venus Express entered its permanent working orbit with an orbital period of 18 hours.

On May 29, the station conducted an infrared survey of the south polar region, finding a vortex of a very unexpected shape: with two "zones of calm", which are intricately connected with each other. Having studied the picture in more detail, the scientists came to the conclusion that there are 2 different structures in front of them, lying at different heights. How stable this atmospheric formation is is not yet clear.

On July 29, VIRTIS took 3 pictures of the atmosphere of Venus, from which a mosaic was made showing its complex structure. The pictures were taken with an interval of about 30 minutes and did not coincide noticeably at the borders, which indicates the high dynamism of the Venusian atmosphere associated with hurricane winds blowing at speeds of over 100 m / s.

Another spectrometer installed on Venus Express, SPICAV, found that clouds in the atmosphere of Venus can rise up to 90 kilometers in height in the form of dense fog and up to 105 kilometers, but in the form of a more transparent haze. Previously, other spacecraft recorded clouds only up to a height of 65 kilometers above the surface.

In addition, using the SOIR unit as part of the SPICAV spectrometer, scientists discovered "heavy" water in the atmosphere of Venus, which includes atoms of the heavy isotope of hydrogen - deuterium. Ordinary water in the planet's atmosphere is enough to cover its entire surface with a 3-centimeter layer.

By the way, knowing the percentage of "heavy water" to ordinary water, you can estimate the dynamics of the water balance of Venus in the past and present. Based on these data, it was suggested that in the past, an ocean with a depth of several hundred meters could exist on the planet.

Another important scientific instrument installed on the Venera Express, the ASPERA plasma analyzer, recorded the high rate of escape of matter from the Venusian atmosphere, and also tracked the trajectories of other particles, in particular helium ions, which are of solar origin.

"Venus Express" continues to operate to this day, although the estimated duration of the mission of the apparatus directly on the planet was 486 Earth days. But the mission could be extended, if the station's resources permit, for the same period of time, which apparently happened.

At present, Russia is already developing a fundamentally new spacecraft - the Venera-D interplanetary station, intended for a detailed study of the atmosphere and surface of Venus. The station is expected to be able to operate on the planet's surface for 30 days, possibly more.

On the other side of the ocean - in the United States, at the request of NASA, the Global Aerospace corporation has also recently begun to develop a project to explore Venus using a balloon, the so-called. "Controlled aerial exploration robot" or DARE.

It is assumed that the DARE balloon with a diameter of 10 m will cruise in the cloud layer of the planet at an altitude of 55 km. DARE's altitude and direction will be controlled by a stratoplane that looks like a small plane.

On the cable under the balloon, there will be a gondola with television cameras and several dozen small probes that will be dropped onto the surface in areas of interest to observe and study the chemical composition of various geological structures on the planet's surface. These areas will be selected on the basis of a detailed survey of the area.

The duration of the balloon mission is from six months to a year.

Orbital motion and rotation of Venus

Fig. 19 Distance from the terrestrial planets to the Sun. Credit: Lunar and Planetary Institute

Around the Sun, the planet Venus moves in a close to a circular orbit, inclined to the plane of the ecliptic at an angle of 3 ° 23 "39" ". The eccentricity of the Venusian orbit is the smallest in the solar system, and is only 0.0068. Therefore, the distance from the planet to the Sun always remains approximately the same, amounting to 108.21 million km But the distance between Venus and the Earth varies, and within wide limits: from 38 to 258 million km.

In its orbit, located between the orbits of Mercury and the Earth, the planet Venus moves with an average speed of 34.99 km / sec and a sidereal period equal to 224.7 Earth days.

Venus rotates around its axis much slower than in orbit: the Earth has time to rotate 243 times, and Venus only 1. the period of its rotation around its axis is 243.0183 Earth days.

Moreover, this rotation does not occur from west to east, like all other planets, except Uranus, but from east to west.

The reverse rotation of the planet Venus leads to the fact that the day on it lasts 58 Earth days, the same night lasts, and the duration of Venusian days is 116.8 Earth days, so during the Venusian year you can see only 2 rises and 2 sets of the Sun, and the rise will occur in the west, and set in the east.

The speed of rotation of the solid body of Venus can be confidently determined only by radar, because of the continuous cloud cover hiding its surface from the observer. For the first time, a radar reflection from Venus was obtained in 1957, and at first radio pulses were sent to Venus in order to measure the distance to refine the astronomical unit.

In the 1980s, the USA and the USSR began to investigate the spreading of the reflected pulse in frequency ("the spectrum of the reflected pulse") and the delay in time. Frequency blur is explained by the rotation of the planet (Doppler effect), dragging in time - by different distances to the center and edges of the disk. These studies were carried out mainly on radio waves in the decimeter range.

In addition to the fact that the rotation of Venus is reversed, it has another very interesting feature. The angular speed of this rotation (2.99 10 -7 rad / sec) is just such that during the lower conjunction Venus is facing the Earth all the time with the same side. The reasons for this consistency between the rotation of Venus and the orbital motion of the Earth are not yet clear ...

And finally, let's say that the inclination of the equatorial plane of Venus to the plane of its orbit does not exceed 3 °, which is why seasonal changes on the planet are insignificant, and there are no seasons at all.

The internal structure of the planet Venus

The average density of Venus is one of the highest in the solar system: 5.24 g / cm 3, which is only 0.27 g less than the density of the Earth. The masses and volumes of both planets are also very similar, with the difference that the Earth's parameters are somewhat larger: the mass is 1.2 times, the volume is 1.15 times.

fig. 20 Internal structure of the planet Venus. Credit: NASA

Based on the considered parameters of both planets, we can conclude that their internal structure is similar. And indeed: Venus, like the Earth, consists of 3 layers: crust, mantle and core.

The uppermost layer is the Venusian crust, about 16 km thick. The crust consists of basalts with a low density - about 2.7 g / cm 3, and formed as a result of the outpouring of lava on the surface of the planet. This is probably why the Venusian crust has a relatively small geological age - about 500 million years. According to some scientists, the process of the outpouring of lava flows onto the surface of Venus occurs with a certain periodicity: first, the substance in the mantle, due to the decay of radioactive elements, heats up: convective flows or plumes break the planet's crust, forming unique surface details - tessera. Having reached a certain temperature, lava flows make their way to the surface, covering almost the entire planet with a layer of basalts. The outpouring of basalts occurred repeatedly, and during periods of calm volcanic activity, lava plains were subjected to stretching due to cooling, and then belts of Venusian cracks and ridges were formed. About 500 million years ago, the processes in the upper mantle of Venus seemed to have calmed down, possibly due to the depletion of internal heat.

Under the planetary crust lies the second layer - the mantle, which extends to a depth of about 3300 km to the border with the iron core. Apparently, the mantle of Venus consists of two layers: a solid lower mantle and a partially molten upper one.

The core of Venus, whose mass is about a quarter of the entire mass of the planet, and the density is 14 g / cm 3, is solid or partially molten. This assumption was made based on the study of the planet's magnetic field, which simply does not exist. And since there is no magnetic field, then there is no source that this magnetic field generates, i.e. in the iron core there is no movement of charged particles (convective flows), therefore, the movement of matter in the core does not occur. True, the magnetic field may not be generated due to the slow rotation of the planet ...

Surface of the planet Venus

The shape of the planet Venus is close to spherical. More precisely, it can be represented by a triaxial ellipsoid, in which the polar compression is two orders of magnitude less than that of the Earth.

In the equatorial plane, the semiaxis of the Venus ellipsoid are 6052.02 ± 0.1 km and 6050.99 ± 0.14 km. The polar semiaxis is 6051.54 ± 0.1 km. Knowing these dimensions, you can calculate the surface area of ​​Venus - 460 million km 2.

fig.21 Comparison of the planets of the solar system. Credit: website

Data on the dimensions of Venus's solid body were obtained using radio interference methods and refined using radio altimetric and trajectory measurements when the planet was within the reach of spacecraft.

fig.22 Estla region on Venus. A high volcano is visible in the distance. Credit: NASA / JPL

Most of the surface of Venus is occupied by plains (up to 85% of the entire area of ​​the planet), among which are dominated by smooth, slightly complicated by a network of narrow winding gently sloping ridges, basalt plains. A much smaller area than smooth ones is occupied by lobed or hilly plains (up to 10% of the surface of Venus). Typical for them are tongue-like protrusions, like blades, differing in radio brightness, which can be interpreted as extensive lava sheets of low-viscosity basalts, as well as numerous cones and domes 5-10 km in diameter, sometimes with craters on the tops. There are also sections of plains on Venus, densely covered with cracks or practically not disturbed by tectonic deformations.

fig. 23 Ishtar archipelago. Credit: NASA / JPL / USGS

In addition to the plains on the surface of Venus, three vast elevated regions have been discovered, which are named after the earthly goddesses of love.

One such area, the Ishtar Archipelago, is a vast mountainous region in the northern hemisphere, comparable in size to Australia. In the center of the archipelago lies the volcanic Lakshmi plateau, which is twice the area of ​​earthly Tibet. From the west, the plateau is limited by the Akna mountains, from the north-west - by the Freya mountains, up to 7 km in height, and from the south - by the folded Danu mountains and the Vesta and Ut ledges, with a general decrease of up to 3 km or more. The eastern part of the plateau "cuts" into the highest mountain system of Venus - the Maxwell Mountains, named after the English physicist James Maxwell. The central part of the mountain range rises by 7 km, and individual mountain peaks located near the prime meridian (63 ° N and 2.5 ° E) rise to heights of 10.81-11.6 km, 15 km higher than the deep Venusian trench, which lies near the equator.

Another elevated area is the Aphrodite archipelago, which stretches along the Venusian equator, and is even larger in size: 41 million km 2, although the altitudes are lower here.

This vast territory, located in the equatorial region of Venus and stretching for 18 thousand km, covers longitudes from 60 ° to 210 °. It extends from 10 ° N. up to 45 ° S more than 5 thousand km, and its eastern end - the Atla region - stretches up to 30 ° N latitude.

The third elevated region of Venus is the land of Lada, which lies in the southern hemisphere of the planet and is opposite to the Ishtar archipelago. This is a fairly flat area, the average surface height of which is close to 1 km, and the maximum (just over 3 km) is reached in the Quetzalpetlatl crown with a diameter of 780 km.

fig.24 Tessera Ba "het. Credit: NASA / JPL

In addition to these elevated regions, because of their size and heights, called "lands", others, less extensive, stand out on the surface of Venus. Such, for example, as tesserae (from the Greek - tile), which are hills or highlands ranging in size from hundreds to thousands of kilometers, the surface of which is intersected in different directions by systems of stepped ridges and troughs separating them, formed by swarms of tectonic faults.

Ridges or ridges within the tessera can be linear and extended: up to many hundreds of kilometers. And they can be sharp or, conversely, rounded, sometimes with a flat top surface, limited by vertical ledges, which resembles a combination of tape grabens and horsts in terrestrial conditions. Often, the ridges resemble a wrinkled film of frozen jelly or rope lavas of the Hawaiian basalts. The height of the ridges can be up to 2 km, and of the ledges - up to 1 km.

The trenches separating the ridges extend far beyond the highlands, stretching for thousands of kilometers across the vast Venusian plains. In topography and morphology, they are similar to the rift zones of the Earth and seem to be of the same nature.

The formation of the tessera themselves is associated with repeated tectonic movements of the upper layers of Venus, accompanied by compressions, stretches, splits, ups and downs of various parts of the surface.

These, I must say, are the most ancient geological formations on the surface of the planet, and therefore the names are appropriated to them: in honor of the goddesses associated with time and fate. Thus, a large upland, stretching for 3,000 km not far from the North Pole, is called the tessera of Fortune, to the south of it is the tessera of Laima, which bears the name of the Latvian goddess of happiness and fate.

Together with lands or continents, tesserae occupy slightly more than 8.3% of the planet's territory, i.e. exactly 10 times less area than the plains, and possibly the foundation of a significant, if not all, territory of the plains. The remaining 12% of Venus's territory is occupied by 10 types of relief: crowns, tectonic faults and canyons, volcanic domes, "arachnoids", mysterious channels (grooves, lines), ridges, craters, paters, craters with dark parabolas, hills. Let's consider each of these relief elements in more detail.

Fig. 25 The crown is a unique relief detail on Venus. Credit: NASA / JPL

The crowns, which, along with tesserae, are unique details of the relief of the surface of Venus, are large volcanic depressions of an oval or round shape with a raised central part, surrounded by ramparts, ridges, and depressions. The central part of the wreaths is occupied by a vast intermontane plateau, from which mountain ranges extend in rings, often towering over the central part of the plateau. The ring framing of the crowns is usually incomplete.

Several hundred Ventsov were discovered on the planet Venus, according to the results of research from spacecraft. The crowns differ in size (from 100 to 1000 km) and the age of their constituent rocks.

The crowns were formed, apparently as a result of active convective currents in the mantle of Venus. Around many of the crowns, solidified lava flows are observed, diverging to the sides in the form of wide tongues with a scalloped outer edge. Apparently, it was the crowns that could serve as the main sources through which molten matter from the interior came to the surface of the planet, solidifying forming vast flat areas, occupying up to 80% of the territory of Venus. These abundant sources of molten rocks are named after the goddesses of fertility, harvest, flowers.

Some scientists believe that the crowns are preceded by another specific form of Venusian relief - the arachnoid. Arachnoids, which received their name due to their external resemblance to spiders, resemble crowns in shape, but are smaller in size. The bright lines extending from their centers for many kilometers may correspond to surface faults created when magma escaped from the interior of the planet. In total, about 250 arachnoids are known.

In addition to tesserae, crowns and arachnoids, the formation of tectonic faults or troughs is associated with endogenous (internal) processes. Tectonic faults are often grouped into extended (up to thousands of kilometers) belts, which are very widespread on the surface of Venus and can be associated with other structural landforms, for example, canyons, which in their structure resemble terrestrial continental rifts. In some cases, an almost orthogonal (rectangular) pattern of mutually intersecting cracks is observed.

fig. 27 Mount Maat. Credit: JPL

Volcanoes are very widespread on the surface of Venus: there are thousands of them here. Moreover, some of them reach enormous sizes: up to 6 km in height and 500 km in width. But most of the volcanoes are much smaller: only 2-3 km in diameter and 100 m in height. The vast majority of Venusian volcanoes are extinct, but some are still erupting. The most obvious candidate for an active volcano is Mount Maat.

In a number of places on the surface of Venus, mysterious grooves and lines from hundreds to several thousand kilometers in length and 2 to 15 km wide have been discovered. Outwardly, they look like river valleys and have the same features: meander convolutions, divergence and convergence of separate "channels", and, in rare cases, something similar to a delta.

The longest channel on the planet Venus is the Baltis Valley, with a length of about 7000 km with a very consistent (2-3 km) width.

By the way, the northern part of the Baltis Valley was discovered in the images of the AMS "Venera-15" and "Venera-16", but the resolution of the images at that time was not high enough to distinguish the details of this formation, and it was mapped as an extended crack of unknown origin.

Fig. 28 Channels on Venus within the land of Lada. Credit: NASA / JPL

The origin of the Venusian valleys or channels remains a mystery, primarily because scientists do not know of a liquid capable of cutting through the surface over such distances. Calculations made by scientists have shown that basaltic lavas, the traces of which are widespread on the entire surface of the planet, would not have enough heat reserves to continuously flow and melt the substance of the basalt plains, cut through them channels for thousands of kilometers. After all, such channels are known, for example, on the Moon, although their length is only tens of kilometers.

Therefore, it is likely that the liquid that cut through the basaltic plains of Venus for hundreds and thousands of kilometers could be overheated komatiite lavas or even more exotic liquids like molten carbonates or molten sulfur. Until the end, the origin of the valleys of Venus is unknown ...

In addition to the valleys, which are negative forms of relief, positive forms of relief are also common on the plains of Venus - ridges, also known as one of the components of the specific relief of the tesserae. The ridges are often formed into long (up to 2000 km or more) belts with a width of the first hundreds of kilometers. The width of a separate ridge is much smaller: rarely up to 10 km, and on the plains it is reduced to 1 km. The heights of the ridges are from 1.0-1.5 to 2 km, and of the scarps that limit them - up to 1 km. Light winding ridges against the background of a darker radio image of the plains represent the most characteristic pattern of the surface of Venus and occupy ~ 70% of its area.

Such details of the surface of Venus as hills are very similar to ridges, with the difference that their sizes are smaller.

All the above forms (or types) of the relief of the surface of Venus owe their origin to the internal energy of the planet. There are only three types of relief, the origin of which is caused by external reasons, on Venus: craters, paters and craters with dark parabolas.

Unlike many other bodies of the solar system: terrestrial planets, asteroids, relatively few impact meteorite craters have been found on Venus, which is associated with active tectonic activity, which ceased 300-500 million years ago. Volcanic activity proceeded very violently, since otherwise the number of craters in older and younger sites would differ markedly and their distribution over the area would not be random.

In total, 967 craters have been discovered on the surface of Venus, with a diameter of 2 to 275 km (near the Mead crater). Craters are conventionally divided into large (over 30 km) and small (less than 30 km), which include 80% of the total number of all craters.

The density of impact craters on the surface of Venus is very low: about 200 times less than on the Moon and 100 times less than on Mars, which corresponds to only 2 craters per 1 million km 2 of the Venusian surface.

By examining images of the planet's surface taken by the "Magellan" spacecraft, scientists were able to see some aspects of the formation of impact craters in the conditions of Venus. Around the craters, light rays and rings were found - the rock thrown out during the explosion. In many craters, part of the emissions is a fluid substance that usually forms extensive streams tens of kilometers long directed to one side of the crater. So far, scientists have not yet figured out what kind of liquid it is: an overheated shock melt or a suspension of a fine-grained solid and melt droplets suspended in a near-surface atmosphere.

Several Venusian craters are flooded with lava from the adjacent plains, but the overwhelming majority have a very distinct appearance, which indicates a weak intensity of material erosion processes on the surface of Venus.

The bottom of most craters on Venus is dark, indicating a smooth surface.

Another common type of terrain is craters with dark parabolas, and the main area is occupied by dark (in the radio image) parabolas, the total area of ​​which is almost 6% of the entire surface of Venus. The color of the parabolas is due to the fact that they are composed of a cover of fine-grained material up to 1–2 m thick, formed due to emissions from impact craters. It is also possible that this material can be processed by aeolian processes, which prevailed in a number of regions of Venus, leaving many kilometers of stripe-like aeolian relief.

Craters and craters with dark parabolas are similar to paters - irregularly shaped craters or complex craters with scalloped edges.

All of these data were collected when the planet Venus was within the reach of spacecraft (Soviet, Venus series, and American, Mariner and Pioneer Venus series).

So, in October 1975, the descent vehicles of the AMS "Venera-9" and "Venera-10" made a soft landing on the planet's surface and transmitted images of the landing site to the Earth. These were the first photographs in the world transmitted from the surface of another planet. The image was obtained in visible light using a telephotometer - a system that, according to the principle of operation, resembles a mechanical television.

In addition to photographing the surface of the AMS "Venera-8", "Venera-9" and "Venera-10", the density of surface rocks and the content of natural radioactive elements in them were measured.

At the landing sites of Venera-9 and Venera-10, the density of surface rocks was close to 2.8 g / cm igneous rocks of the earth's crust ...

In 1978, the American Pioneer-Venus spacecraft was launched, the result of which was a topographic map based on radar surveys.

Finally, in 1983, the spacecraft Venera-15 and Venera-16 entered orbit around Venus. Using radar, they mapped the planet's northern hemisphere to a parallel of 30 ° at a scale of 1: 5,000,000, and for the first time discovered such unique surface features of Venus as tesserae and crowns.

Even more detailed maps of the entire surface with details up to 120 m in size were obtained in 1990 by the Magellan ship. With the help of computers, radar information has been turned into photographic images of volcanoes, mountains and other landscape details.

fig.30 Topographic map of Venus, compiled from images of the interplanetary station "Magellan". Credit: NASA

According to the decision of the International Astronomical Union, on the map of Venus there are only female names, since she herself, the only one of the planets, bears a female name. There are only 3 exceptions to this rule: Maxwell Mountains, Alpha and Beta regions.

The names for the details of its relief, which are taken from the mythologies of various peoples of the world, are assigned in accordance with the routine. Like this:

The hills are named after goddesses, titanids, giantesses. For example, the region of Ulfrun, named after one of the nine giantesses in Scandinavian myths.

The lowlands are the heroines of myths. In honor of one of these heroines of ancient Greek mythology, the deepest lowland of Atalanta, lying in the northern latitudes of Venus, is named.

Furrows and lines are named after female warrior mythological characters.

Crowns in honor of the goddesses of fertility, agriculture. Although the most famous of them is Pavlova's crown with a diameter of about 350 km, named after a Russian ballerina.

The ridges are named after the goddesses of the sky, female mythological characters associated with the sky and light. Thus, along one of the plains, the Witch's ridges stretched. And the Bereginya plain from the northwest to the southeast is crossed by the Gera ridges.

The lands and plateaus are named after the goddesses of love and beauty. So, one of the continents (lands) of Venus is called the land of Ishtar and is a high-mountainous region with a vast plateau Lakshmi of volcanic origin.

Canyons on Venus are named after mythological characters associated with the forest, hunting, or the moon (similar to Roman Artemis).

The mountainous terrain in the northern hemisphere of the planet is crossed by the extended Baba Yaga canyon. Within the regions of Beta and Phoebe, the Devan canyon stands out. And from the region of Themis to the land of Aphrodite, the largest Venusian quarry, Parge, stretches for more than 10 thousand km.

Large craters are named after famous women. Small craters are simply ordinary female names. So, on the high-mountainous plateau Lakshmi you can find small craters Berta, Lyudmila and Tamara, located south of the Freya Mountains and east of the large Osipenko crater. Near the crown of Nefertiti is the Potanin crater, named after the Russian explorer of Central Asia, and nearby is the Voynich crater (by the English writer, author of the novel The Gadfly). And the largest crater on the planet was named after the American ethnographer and anthropologist Margaret Mead.

Paters are called according to the same principle as large craters, i.e. by the names of famous women. Example: Father Salfo.

The plains are named after the heroines of various myths. For example, the plains of Snegurochka and Baba Yaga. The Louhi Plain, the mistress of the North in Karelian and Finnish myths, stretches around the North Pole.

Tessera are named after the goddesses of fate, happiness, luck. For example, the largest among the tessera of Venus is called the Tessera of Tellur.

The ledges are in honor of the goddesses of the hearth: Vesta, Ut, etc.

I must say that the planet is the leader in the number of named parts among all planetary bodies. On Venus and the greatest variety of names for their origin. There are names from the myths of 192 different nationalities and ethnic groups from all over the world. Moreover, the names are scattered across the planet, without the formation of "national regions".

And in the conclusion of the description of the surface of Venus, we give a brief structure of the modern map of the planet.

For the zero meridian (corresponds to the Earth's Greenwich) on the map of Venus, back in the mid-60s, a meridian was adopted, passing through the center of a light (on radar images) rounded area with a diameter of 2 thousand km, located in the southern hemisphere of the planet and called the Alpha region by the initial letter of the Greek alphabet. Later, as the resolution of these images increased, the position of the prime meridian was shifted by about 400 km to pass through a small bright spot in the center of a large ring structure 330 km across called Eve. After the creation of the first extensive maps of Venus in 1984, it was discovered that exactly on the prime meridian, in the northern hemisphere of the planet, there is a small crater with a diameter of 28 km. The crater was named Ariadne, after the heroine of Greek myth, and was much more convenient as a reference point.

The prime meridian, together with the 180 ° meridian, divides the surface of Venus into 2 hemispheres: eastern and western.

Atmosphere of Venus. Physical conditions on the planet Venus

Above the lifeless surface of Venus lies a unique atmosphere, the densest in the solar system, discovered in 1761 by M.V. Lomonosov, who observed the passage of the planet across the solar disk.

fig.31 Venus covered by clouds. Credit: NASA

The atmosphere of Venus is so dense that it is absolutely impossible to see through it any details on the planet's surface. Therefore, for a long time, many researchers believed that the conditions on Venus were close to those that were on Earth in the Carboniferous period, and therefore, a similar fauna also lives there. However, studies carried out with the help of descent vehicles of interplanetary stations have shown that the climate of Venus and the climate of the Earth are two big differences and there is nothing in common between them. So, if the temperature of the lower air layer on Earth rarely exceeds + 57 ° C, then on Venus the temperature of the near-surface air layer reaches 480 ° C, and its daily fluctuations are insignificant.

Significant differences are also observed in the composition of the atmospheres of the two planets. If in the atmosphere of the Earth the predominant gas is nitrogen, with a sufficient content of oxygen, an insignificant content of carbon dioxide and other gases, then in the atmosphere of Venus the situation is exactly the opposite. The predominant share of the atmosphere is carbon dioxide (~ 97%) and nitrogen (about 3%), with small additions of water vapor (0.05%), oxygen (thousandths of a percent), argon, neon, helium and krypton. In very small quantities there are also impurities SO, SO 2, H 2 S, CO, HCl, HF, CH 4, NH 3.

The pressure and density of the atmospheres of both planets are also very different. For example, the atmospheric pressure on Venus is about 93 atmospheres (93 times more than on Earth), and the density of the Venusian atmosphere is almost two orders of magnitude higher than the density of the Earth's atmosphere and only 10 times less than the density of water. Such a high density cannot but affect the total mass of the atmosphere, which is approximately 93 times the mass of the Earth's atmosphere.

As many astronomers now believe; high surface temperature, high atmospheric pressure and high relative content of carbon dioxide are factors that are apparently related to each other. The high temperature promotes the transformation of carbonate rocks into silicate ones, with the release of CO 2. On Earth, CO 2 binds and transforms into sedimentary rocks as a result of the action of the biosphere, which is absent on Venus. On the other hand, the high content of CO 2 contributes to the heating of the Venusian surface and the lower layers of the atmosphere, which was established by the American scientist Carl Sagan.

In fact, the gas envelope of the planet Venus is a giant greenhouse. It is capable of transmitting solar heat, but does not release it outside, simultaneously absorbing the radiation of the planet itself. The absorbers are carbon dioxide and water vapor. The greenhouse effect also occurs in the atmospheres of other planets. But if in the atmosphere of Mars it raises the average temperature near the surface by 9 °, in the atmosphere of the Earth - by 35 °, then in the atmosphere of Venus this effect reaches 400 degrees!

Some scientists believe that 4 billion years ago, the atmosphere of Venus was more like the Earth's atmosphere with liquid water on the surface, and it was the evaporation of this water that caused the uncontrollable greenhouse effect that is still observed today ...

The atmosphere of Venus consists of several layers that differ greatly in density, temperature and pressure: the troposphere, mesosphere, thermosphere and exosphere.

The troposphere is the lowest and densest layer of the Venusian atmosphere. It contains 99% of the mass of the entire atmosphere of Venus, of which 90% - up to an altitude of 28 km.

The temperature and pressure in the troposphere decrease with altitude, reaching at altitudes close to 50-54 km, values ​​of + 20 ° + 37 ° C and a pressure of only 1 atmosphere. Under such conditions, water can exist in liquid form (in the form of tiny droplets), which, together with the optimal temperature and pressure, similar to those near the Earth's surface, creates favorable conditions for life.

The upper border of the troposphere lies at an altitude of 65 km. above the surface of the planet, separating from the layer lying above - the mesosphere - by the tropopause. Hurricane winds prevail here with speeds of 150 m / s and above, against 1 m / s at the very surface.

Winds in the atmosphere of Venus are created by convection: hot air rises above the equator and spreads to the poles. This global rotation is called the Hadley rotation.

Fig. 32 Polar vortex near the south pole of Venus. Credit: ESA / VIRTIS / INAF-IASF / Obs. de Paris-LESIA / Univ. of Oxford

At latitudes close to 60 °, Hadley's rotation stops: hot air descends and begins to move back to the equator, this is facilitated by the high concentration of carbon monoxide in these places. However, the rotation of the atmosphere does not stop and north of the 60s latitudes: the so-called. polar collars. They are characterized by low temperatures, high position of clouds (up to 72 km.).

Their existence is a consequence of a sharp rise in air, as a result of which adiabatic cooling is observed.

Around the poles of the planet, framed by "polar collars", there are gigantic polar vortices, four times larger than their terrestrial counterparts. Each vortex has two eyes - centers of rotation, which are called polar dipoles. Eddies rotate with a period of about 3 days in the direction of the general rotation of the atmosphere, with wind speeds ranging from 35-50 m / s near their outer edges to zero at the poles.

Polar vortices, according to astronomers today, are anticyclones with descending air currents in the center and rising sharply near the polar collars. Similar to Venus's polar vortices, structures on Earth are winter polar anticyclones, especially the one that forms over Antarctica.

The Mesosphere of Venus extends at heights from 65 to 120 km and can be divided into 2 layers: the first one lies at an altitude of 62-73 km, has a constant temperature and is the upper boundary of the clouds; the second - at an altitude between 73-95 km, the temperature here drops with altitude, reaching at the upper limit of its minimum of -108 ° C. Above 95 km above the surface of Venus, the mesopause begins - the boundary between the mesosphere and the higher thermosphere. Within the mesopause, the temperature increases with height, reaching + 27 ° + 127 ° C on the day side of Venus. On the night side of Venus, within the mesopause, significant cooling occurs and the temperature drops to -173 ° C. This region, the coldest on Venus, is sometimes even called the cryosphere.

At altitudes above 120 km, the thermosphere lies, which extends to an altitude of 220-350 km, to the border with the exosphere - an area where light gases leave the atmosphere and mainly only hydrogen is present. The exosphere ends, and with it the atmosphere at an altitude of ~ 5500 km, where the temperature reaches 600-800 K.

Within the meso- and thermosphere of Venus, as well as in the lower troposphere, the air mass rotates. True, the air mass moves not in the direction from the equator to the poles, but in the direction from the daytime side of Venus to the nighttime side. On the daytime side of the planet, a powerful rise of warm air occurs, which spreads at altitudes of 90-150 km, moving to the night side of the planet, where the heated air drops sharply downward, as a result of which adiabatic heating of the air occurs. The temperature in this layer is only -43 ° C, which is as much as 130 ° higher than in general on the night side of the mesosphere.

Data on the characteristics and composition of the Venusian atmosphere were obtained by the AMS of the Venera series with serial numbers 4, 5 and 6. Venus 9 and 10 clarified the water vapor content in the deep layers of the atmosphere, finding out that the maximum water vapor is contained at an altitude of 50 km , where it is a hundred times more than that of a solid surface, and the proportion of steam approaches one percent.

In addition to studying the composition of the atmosphere, the interplanetary stations "Venera-4, 7, 8, 9, 10" measured the pressure, temperature and density in the lower layers of the atmosphere of Venus. As a result, it was found that the temperature on the surface of Venus is about 750 ° K (480 ° C), and the pressure is close to 100 atm.

The Venera-9 and Venera-10 descent vehicles also received information regarding the structure of the cloud layer. So, at altitudes from 70 to 105 km, there is a rarefied stratospheric haze. Below, at an altitude of 50 to 65 km (rarely up to 90 km), there is the densest cloud layer, which in its optical properties is closer to a rarefied fog than to clouds in the terrestrial sense of the word. The visibility range here reaches several kilometers.

Under the main cloud layer - at heights from 50 to 35 km, the density drops several times, and the atmosphere attenuates solar radiation mainly due to Rayleigh scattering in CO 2.

Subcloud haze appears only at night, spreading down to the level of 37 km - by midnight and up to 30 km - by dawn. By noon, this haze clears.

Fig. 33 Lightning in the atmosphere of Venus. Credit: ESA

The color of Venus's clouds is orange-yellow, due to the significant content of CO2 in the planet's atmosphere, the large molecules of which scatter this particular part of the sunlight, and the composition of the clouds themselves, consisting of 75-80% sulfuric acid (possibly even fluoride-sulfuric ) with admixtures of hydrochloric and hydrofluoric acids. The composition of the clouds of Venus was revealed in 1972 by American researchers Louise and Andrew Young, as well as Godfrey Sill, independently of each other.

Studies have shown that acid in Venusian clouds is chemically formed from sulfur dioxide (SO 2), which can be sourced from sulfur-bearing surface rocks (pyrites) and volcanic eruptions. Volcanoes manifest themselves in another way: their eruptions generate powerful electrical discharges - real thunderstorms in the atmosphere of Venus, which were repeatedly recorded by instruments of the Venera series stations. Moreover, thunderstorms on the planet Venus are very strong: lightning strikes 2 orders of magnitude more often than in the Earth's atmosphere. This phenomenon is called the "Electric Dragon of Venus".

The clouds are very bright, reflecting 76% of the light (this is comparable to the reflectivity of cumulus clouds in the atmosphere and polar ice caps on the Earth's surface). In other words, more than three-fourths of the solar radiation is reflected by the clouds and only less than one-fourth goes down.

Cloud temperature - from + 10 ° to -40 ° С.

The cloud layer is rapidly moving from east to west, making one revolution around the planet in 4 Earth days (according to the observations of "Mariner-10").

The magnetic field of Venus. The magnetosphere of the planet Venus

The magnetic field of Venus is insignificant - its magnetic dipole moment is less than that of the Earth, at least by five orders of magnitude. The reasons for such a weak magnetic field are: the slow rotation of the planet around its axis, the low viscosity of the planetary core, perhaps there are other reasons. Nevertheless, as a result of the interaction of the interplanetary magnetic field with the ionosphere of Venus, magnetic fields of low intensity (15-20 nT) are created in the latter, randomly located and unstable. This is the so-called called Venus magnetosphere, which has a bow shock, a magnetosheath, a magnetopause, and a magnetosphere tail.

The bow shock wave lies at an altitude of 1900 km above the surface of the planet Venus. This distance was measured in 2007 during the solar minimum. During maximum solar activity, the shock wave height increases.

The magnetopause is located at an altitude of 300 km, which is slightly higher than the ionopause. There is a magnetic barrier between them - a sharp increase in the magnetic field (up to 40 T), which prevents the penetration of solar plasma into the depths of Venus's atmosphere, at least during the minimum solar activity. In the upper layers of the atmosphere, significant losses of O +, H + and OH + ions are associated with the activity of the solar wind. The length of the magnetopause is up to ten radii of the planet. The very same magnetic field of Venus, or rather its tail, extends to several tens of Venusian diameters.

The ionosphere of the planet, which is associated with the presence of the magnetic field of Venus, arises under the influence of significant tidal influences due to the relative proximity to the Sun, due to which an electric field is formed above the surface of Venus, the intensity of which can be twice the intensity of the "clear weather field" observed above the surface of the Earth ... The ionosphere of Venus is located at altitudes of 120-300 km and consists of three layers: between 120-130 km, between 140-160 km and between 200-250 km. At altitudes close to 180 km, there may be an additional layer. The maximum number of electrons per unit volume - 3 × 10 11 m -3 - was found in layer 2 near the sunflower center.

What will the surface of Venus look like if you remove all the clouds that hide it? On the Magellan spacecraft flying to Venus, radars were installed in order to pull the veil from the true face of Venus and reproduce a detailed image of its surface. as a result, you see the map of Venus in false colors. Mountains are shown in red, valleys are shown in blue. The resolution reached on the map is 3 km. Magellan made this map from 1990 to 1994. Areas that Magellan could not observe were later filled with observations from the Arecibo radio telescope. The large yellow-red area to the north is the Ishtar Valley, flanking the Maxwell Mountains, the highest mountains on Venus. The large flat highlands on Venus are similar to the continents on Earth. Scientists are extremely interested in studying the geology of Venus, as this planet is very similar to Earth.

Venus is one of the most beautiful and brightest luminaries in the sky (the planet's brilliance is due to the reflection of the sun's rays from the powerful cloudy atmosphere). It is no coincidence that it was she who was assigned the names of the goddesses of love and beauty: in Babylon the planet was called Ishtar, in ancient Greece - Aphrodite, in ancient Rome - Venus. Due to dense clouds, the surface of Venus cannot be seen even from the orbit of its artificial satellite. The relief of its surface can be studied only by radar methods.

Venus is in the morning sky before sunrise for 263 days (the period of rotation of the planet). Then it approaches the Sun, and it becomes impossible to observe it for 50 days. Then the planet appears in the evening sky at sunset and also shines for 263 days. Venus is hiding again, already on the 8th day, as it turns out to be between the Earth and the Sun and faces us with the unlit side. This is a repeating cycle. The orbital period of Venus around the Sun is 224.7 days. The sky on Venus is colored orange, turning into yellow-green closer to the horizon.

This image, taken by the Galileo spacecraft, shows how dense clouds are covered in Venus. Venus is very similar to Earth in size and mass, which is why it is often referred to as Earth's sister. However, Venus has a completely different climate. Dense clouds and proximity to the Sun (only Mercury is even closer) make Venus the hottest planet - much hotter than Earth. A human could not survive there, and no life forms were found there. When visible in the sky, Venus is usually the brightest object after the Sun and Moon.

More than 20 spacecraft have visited Venus, including Venus 9, which landed on the surface, and Magellan, which, using radar, was able to look under the clouds and map the surface. This visible light image of Venus was taken by the Galileo spacecraft, which orbited Jupiter from 1995 to 2003. Much remains unknown about Venus, including the cause of the mysterious radio frequency pulses.

Cobwebs are large structures of unknown origin that have only been found on the surface of Venus. These structures received the name Web for their resemblance to the cobwebs that a spider weaves. The cobwebs are concentric ovals surrounded by a complex network of cracks and can extend over 200 km. This image is compiled from radar observations of the Magellan spacecraft that orbited Venus from 1990 to 1994. To date, more than 30 Cobwebs have been found on Venus. Cobwebs can be surprisingly combined with volcanoes. However, it is possible that different Webs are formed through different processes.

If it were possible to look at Venus with the eyes of a radar, then we would see such a picture. The picture shows the spacecraft Magellan's observations of the surface of Venus, processed by the computer. Radar installations were used to map Venus when Magellan flew around our neighbor in 1990-1994. Interesting surface features were found in Magellan's data, including the large circular domes depicted today with a characteristic size of 25 km. It is believed that the domes were formed as a result of volcanic activity, although no one knows for sure. The surface of Venus is so hot and inhospitable that no probe has been there for more than a few minutes.

This image is a slice of the first color panorama of Venus. The panorama was broadcast by a television camera mounted on the Soviet Venera 13 lander. The module was landed on the surface of Venus using a parachute on March 1, 1982. Clouds on Venus are made up of droplets of sulfuric acid and have a surface temperature of about 482 degrees Celsius, while atmospheric pressure is 92 times that of Earth at sea level. Despite these harsh conditions, the Venera 13 lander lasted long enough, sending a series of images to Earth and analyzing Venus's soil. Part of the module is visible at the lower right edge of the picture. The first spacecraft to carry a Soviet lander to Venus was Venera-7 (1970). She first transmitted information from the surface of another planet.

To compose this amazing landscape of Venus, color observations of the Soviet interplanetary probe Venera and radar data from the Magellan spacecraft were used. In this computer-assisted picture, the vertical scale has been specially zoomed in. In the foreground is the edge of the Rift Valley, formed by the sinking of Venus's crust. The valley stretches all the way to the base of Mount Gula, a 3.2 km high volcano (on the right in the picture), which is only 720 km away. On the left is another volcano - Mount Sif. Using radar imaging, it is possible to penetrate the clouds that constantly cover the surface of Venus. With this method, the Magellan apparatus was able to explore more than 98% of the planet's surface, filled with a variety of relief forms.

Venus is often a staging post for spacecraft that fly to distant gas giant planets on the outskirts of the solar system. Why do they fly to Venus first? Such a gravitational maneuver is necessary in order for the spacecraft to acquire energy during such a short-term meeting and accelerate due to the planet's gravitational field, having consumed a certain amount of fuel for a long-term interplanetary mission. This colorful picture of Venus was captured by the Galileo spacecraft just after the gravitational maneuver in February 1990, which flew to explore Jupiter. Swirls of sulphurous clouds are visible in this image of the veiled planet. The bright area is a solar flare on the upper clouds of Venus.

The launch of the automatic spacecraft Venera-Express took place in November 2005 thanks to the European Space Agency. In April 2006, the ship flew to Venus. And now Venus Express is turning around our sister and sending us photographs. Today's film was captured while the ship was passing over the northern hemisphere of Venus in late May 2006. The image was taken in ultraviolet light, and therefore is presented in false colors.

9.

Venus goes through different phases. Like our Moon, Venus can appear as a full disk or as a thin crescent moon. However, Venus, which is often the brightest object in the sky just after sunset or before dawn, has such a small angular size that its phases can only be clearly seen with binoculars or a small telescope. This sequence of images was taken over several months and shows not only a change in phase, but also a change in the apparent angular size of Venus. In the negative image in the middle of the sequence, Venus is in a new phase, which occurred during the rare partial eclipse of the Sun by Venus in 2004.

10.

If you could look at the north pole of Venus, what would you see? 1990 to 1994 the Magellan probe was in orbit around Venus. With the help of the radar installed on it, it was possible to look under the dense Venusian clouds and build a topographic map of the surface. In the center is the North Pole, and the bright spot below the center is the highest Maxwell Mountains on Venus. Other notable surface formations include numerous mountains, crowns, impact craters, tesserae, mountain ranges and lava flows. Venus is similar in size and mass to Earth, but unlike Earth, it has a dense atmosphere composed mainly of carbon dioxide. This atmosphere traps heat very effectively, resulting in surface temperatures typically exceeding 700 degrees Kelvin. At this temperature, lead begins to melt.

11.

What's happening over the south pole of Venus? To find out, experts have long studied the photographs taken by the robotic spacecraft Venus Express during its flights over the poles of Venus, the overheated twin of the Earth. To everyone's surprise, the photographs taken by the Venera Express cameras quite recently did not confirm the previous findings. Instead of the previously found double hurricane, an unusual single vortex was discovered in the planet's clouds. Today's image was taken very recently in infrared light. In the picture, the darker areas correspond to the higher temperatures of the Venusian atmosphere, which means they show where the clouds are located closer to the planet's surface. It is not clear why in vortices sometimes two funnels appear at once, and sometimes only one. But the study of the features of their dynamics can shed light on the processes of birth and evolution and earthly hurricanes. Recently, the Japanese satellite Akatsuki was supposed to join the European spacecraft Venus Express in orbit of Venus. The Akatsuki climatic orbiter, launched by the Japanese aerospace agency JAXA on May 21 this year to Venus, missed. According to the plan, he was supposed to start maneuvers in October in order to occupy the required orbit around Venus. According to JAXA, all the necessary commands were given to him on time, but yesterday Japan was forced to report a failure. The probe did not enter orbit, but instead began to move away from Venus, starting to move around the Sun.
12.

The hot and cracked surface of Venus is covered in numerous rolling hills. Despite the fact that the surface of Venus has never been photographed from this height, such images can be generated by digital processing of data obtained from a long distance with a highly sensitive radar. The image covers an area about 100 kilometers wide, located in a volcanic region known as Yavine Corona. The frame shows numerous cracks and faults on the surface. The black bar in the upper right part of the frame corresponds to the area for which there is no data. The temperature and pressure on the surface of Venus are so great that the unmanned space station that landed on the surface was able to operate for only a few hours.

13.

Taken from Papago Park in Phoenix, Arizona in April 1998 by T. Polakis. The sparkling sources in this picture are Phoenix City, Moon, Venus and Jupiter. Such closeness of these sources is very rare.

14.

If you get up early in the morning, you can admire Venus shining like the morning star above the eastern horizon. Captured on October 7, 2007 by Jay Welle in this predawn skyscape, Venus is in the upper right corner. The crescent moon and Saturn (bottom left) are also visible. Both planets and the Moon can be easily closed with an outstretched fist, since they are all located in a sector of five degrees. Ashlight - Sunlight reflected off the daytime side of planet Earth illuminates the nighttime side of the Moon. If you look closely at Saturn, you can see a bright dot next to it - its largest satellite, Titan.

15.

Wandering the ecliptic along with other planets visible to the naked eye, in early April 2004, Venus passed the Pleiades star cluster, providing ground-based observers with an excellent photo opportunity. The Pleiades, cataloged as M45, are beautiful in themselves. Long exposure images show that they are immersed in a blue reflection nebula. However, in this image (by David Cortner), taken on the evening of April 3rd, bright Venus approached the Seven Sisters and eclipsed the faint glow of the cosmic cloud. This picture serves as a clear illustration of cosmic contrasts: for example, Venus looks about 700 times brighter than Alcyone, the brightest star in the Pleiades. If Venus is at a distance of 5 light minutes from Earth, then Alcyone and other stars of the Pleiades are about 400 light years away. The age of Venus, formed from the same collapsing nebula that gave birth to the Sun, is about 4.5 billion years. The stars in the Pleiades are apparently only one hundred million years old.

16.

In early June 2004, a rare event occurred - the transit of Venus across the solar disk. The photographs of this event are some of the most expressive in the history of astronomical photography. Wherever the passage could be observed, scientific and artistic surveys were carried out: in Europe, in most of Asia, Africa and North America. Scientifically, there is a debate about the so-called "black drop effect": scientists believe that its appearance is due to the characteristics of the transparency of the camera on the telescope, and not the atmosphere of Venus. From an artistic point of view, images fall into several categories. The former show the transit of Venus against the backdrop of a detailed image of the Sun's disk. Others are interesting double coincidences: for example, Venus and the silhouette of an airplane against the background of the Sun or Venus and the ISS in low orbit around the Earth. Third images, like the one taken in North Carolina (USA) and brought to your attention (by David Cortner), combine the transit of Venus across the disk of the Sun and a picturesque cloudy picture. At first glance, the disk of the planet Venus can be confused with a small and unusually round cloud in this image.

17.

At the end of the transit of Venus across the solar disk on June 8, 2004, astronomers received this amazing close-up image. The silhouette of Venus is clearly visible on the bright surface of the Sun. Against the blackness of space, a thin arc is noticeable along the edge of the planet, which arose due to the refraction of sunlight into Venusian atmosphere. The arc is part of a luminous atmospheric halo that was first seen as the planet passed across the solar disk in 1761. Then the observations of such a halo served as evidence in favor of the existence of an atmosphere around Venus. The picture was taken with a 1-meter Swedish solar telescope located on the island of La Palma, one of the Canary Islands. The final photo was taken by Mats Lofdahl in the presence of the staff of the Institute of Solar Physics of the Swedish Academy of Sciences Dan Kiselman, Goran Scharmer, Kai Langhans, Peter Dettori.

18.

On this day, it seemed that two of the three heavenly bodies visible in the daytime collided. In reality, the Moon passed in front of Venus. The cover was photographed in Switzerland in the hours before sunset. A few minutes after this shot was taken, the Moon, whose crescent was visible to the right, eclipsed convex Venus. At the left edge of the image, clouds are visible, which at some point threatened to hide the observed phenomenon. 90 minutes later, Venus appeared on the right from behind the bright crescent moon.

19.

Sometimes wonderful things happen in the sky above our heads. For example, in early September 2010, the Moon and Venus were very close to each other in the sky and gave pleasure to those who like to look at the sky around the world. From some places, an even more colorful picture could be observed. Photo taken in Spain today by Isaac Gutierrez Pascual. Here, against the background of the dark blue evening sky, the moon and Venus are posing. In the foreground, dark storm clouds stretched across the entire bottom of the photo, and a white anvil-shaped cloud hovered above them. The dark spots on the background of the clouds represent a flock of birds flying by. However, very soon after the photo was taken, the birds flew away, the storm ended, and Venus and the Moon disappeared over the horizon. Now Venus and the Moon have already diverged at a great angular distance. Although Venus was visible in the evening sky for the whole of September.

20.

On a quiet morning, the predawn sky near the eastern horizon is reflected in the calm water. The photo was taken on May 22 from the banks of the Mullika River, in a forest area known as the "Pine Wasteland" in southern New Jersey on the east coast of the United States (by Jerry Lodriguss). To the left above the horizon is a narrow sunlit crescent of the old Moon. Mars is near the center of the picture, and bright Venus sparkles to the right. Like earthly lights on the banks of a river, bright celestial beacons are reflected in the water in the foreground. Most of the Moon is illuminated by ash light - the light reflected by the illuminated side of planet Earth, so its details can be seen on the dark part of the lunar surface.

21.

The gorgeous colors and dramatic clouds that could be seen at sunset on Monday December 1, 2008 in the western sky were reflected in the waters of the Bay of Brisbane on the Central Coast of New South Wales, Australia. The sky also showed a remarkable conjunction of the lunar crescent, Venus and Jupiter, which together looked like a smiling face. The convergence of two bright planets and the Moon has attracted the attention of lovers of contemplating the sky all over the planet Earth. Astronomer Mike Salway has gone to great lengths to capture this magnificent view as he endured mosquito bites and rainstorms on the swampy shore. From his point of view, in the southern hemisphere, brilliant Venus was higher than the rest of the luminaries from this celestial group.

22.

On December 1st, 2008, the bright planets Venus and Jupiter gathered around the moon's young crescent, a spectacular celestial scene that could be seen in the early evening around the world. However, from some places it was seen that the Moon passed directly in front of Venus - Venus was covered by the Moon, which for some time changed the picture of the approach of heavenly bodies. Taken at dusk from Wheeldon, Austria, this photograph shows the brilliant evening star visible about five minutes before it disappeared behind the dark limb of the moon and disappeared from view for more than an hour. The picture was obtained by superimposing long and short exposures, as a result, the details of the lunar surface are visible on it, illuminated by both weak ash light and the bright light of the sun. The inset shows a photo taken later when the dazzling Venus reappeared in the darkened sky over Breil-sur-Roya in southeastern France from a bright crescent moon. Jupiter, visible above and to the right, about three degrees from Venus and the Moon, is surrounded by its own moons, which in the photograph look like tiny glowing pinheads on either side of the bright planet. Credit: Johann Schedler (Panther Observatory) Sidebar: Vincent Jacques.

23.

This celestial scene was captured after sunset on November 30, 2008 from Mount Wilson Observatory, near Los Angeles in California, USA. Above all in the sky is the farthest of the three luminaries, the planet Jupiter. Venus is much closer to us, it is visible below and to the left of Jupiter and seems unusually blue, as it shines through the clouds in the earth's atmosphere. On the right above the horizon, the growing crescent of our satellite, the Moon, shines. Thin clouds, illuminated by the Moon, appear tinted in an unusual orange color. At the bottom of the picture are the hills of Los Angeles, in some places covered with light fog, and the skyscrapers in the city center are visible near the left edge. The conjunction of Venus and Jupiter will be visible in the western sky just after sunset for most of this month. However, just a few hours after this picture was taken, the Moon approached the celestial duet, eclipsed Venus for a short time, and continued its journey across the sky.

24.

From the windswept summit of Mauna Kea on Hawaii's Big Island, you can enjoy a nightlife like this. The silhouette of the top of the mountain, reaching an altitude of about 4100 meters, is visible against the background, captured at dusk in early December 2005 by Serge Brunier. The volcanic peak rises above a sea of ​​storm clouds illuminated by the bright moon. The planet Venus shines near the Moon like a brilliant evening star. The picture also includes a faint milky-white stripe - a disk of our Galaxy of stars and cosmic dust clouds, stretching from the horizon to the sky along the right edge of the photo.

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On the night of May 19, 2007, Earth's satellite Moon and planet Venus were visible in the same part of the sky, and the smallest distance between them was less than one degree. The compound was captured in this photograph from the vicinity of Quebec City in Quebec, Canada by Jay Oulle. Venus is visible in the lower left of the picture. The rays that appear to come from Venus are actually due to diffraction in the chamber itself. The image is so clear that craters on the moon are clearly visible. Of course, the true physical distance between the two celestial bodies was not unusually small. The apparent connection is actually an optical illusion that occurs when projected onto the celestial sphere. Although the Moon passes around Venus every month, this close encounter in the evening sky is much less common.

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The combination of the two brightest objects in the night sky is a wonderful sight for those who love to admire the night sky just after sunset.
In the image shown here, this phenomenon was photographed through clouds over the coast of Corona del Mar in California, USA. More specifically, the Moon passed about three degrees from Venus on February 23rd, 2004. By Wally Pacholka.
Scientists from Russia and France intend to combine a program for the exploration of Venus: the possibility of combining the Russian mission "Venera-D", which is scheduled to launch in 2015-2016, with the European program of exploration of this planet is currently being considered.

>> How to find Venus in the night sky

How to find Venus in the starry sky- description for an observer from planet Earth. Learn how to use Jupiter, Moon, Mercury, and the constellation Gemini in the photo.

Venus is the second planet from the Sun, so there are no problems with how to find Venus in the starry sky. Use our online star map or carefully study the lower diagrams, where the constellations, planets and auxiliary stars are indicated.

In order not to miscalculate with the place, you can use special applications for phones. Or, let's follow the ancient astronomers and use natural clues.

To find Venus, start at the ecliptic. When you follow the passage of the Sun across the sky, then this line is called the ecliptic. Depending on the season, this route changes: it rises and falls. The maximum is observed during the summer solstice, and the minimum falls on the winter.

Many celestial bodies are easiest to find by lengthening. These are the points where the planets are set closer to the Sun in relation to us. There are two varieties: eastern - located in the evening sky and western - in the morning. Naturally, all this concerns only the perspective of the terrestrial observer. Admire what Venus looks like through a non-professional telescope.

Because of our turnover, the movement of bodies covers 15 degrees per hour. Venus becomes visible only when it approaches 5 degrees to the Sun, so you will not see it 20 minutes after the appearance of the Sun or before it disappears. The planet is located between 45-47 degrees from the star and moves 3 hours and 8 minutes after / in front of the Sun.

If you want to see something other than the bright spot, you need to buy a telescope. In addition, you will need a planetary filter or an off-axis mask. It is good if the mechanism is endowed with an automatic tracking system.