Why does Venus rotate counterclockwise? Hypotheses. Axis of rotation of Venus Period of rotation of Venus around its axis

The latest data about Venus obtained using the Venus Express infrared probe surprised scientists. It turned out that the planet rotates around its axis much more slowly than previously thought, and the day on Venus lasts longer than thought before the latest observations. This may be due to weather processes and the density of the Venusian atmosphere.

Venus Express was launched back in 2006 by the European Space Agency. Its main task is to study the atmosphere, plasma environment and surface of the planet. The automatic space station is equipped with seven types of instruments created by specialists different countries. Spectrometers and a four-channel camera make it possible to map the planet in the spectral range - from ultraviolet to infrared and thus determine the structure and composition of its atmosphere.

In turn, the plasma analyzer and magnetometer help to study the outer space surrounding Venus: to identify the features of the interaction of its atmosphere with the solar wind, the structure of the plasma and the neutral gaseous medium, and the magnetic field. And the radio equipment is designed to study the surface, the neutral atmosphere and ionosphere, the gravitational field and the interplanetary medium. The operation of the equipment is coordinated in such a way that several instruments “work” on one task at once, which makes it possible to reduce the errors in the data obtained and to deeply study the mechanisms of the processes occurring on Venus.

The automatic station makes a revolution in an elliptical polar orbit every 24 hours. Moreover, the pericenter of the orbit is located at an altitude of about 250 kilometers above the North Pole, which allows for the most complete observations at all latitudes. The Venus Express mission is expected to last until 2013.

The researchers compared topographic map Venus, compiled by the VIRTIS mapping spectrometer, with its analogue, compiled in the early nineties of the last century by the Magellan space station. During the comparison process, it was discovered that individual details of the relief of the Venusian surface on the Venus Express map are shifted relative to the calculated points at which they should have been located, according to the Magellan changes, by more than ten kilometers. Consequently, the earlier model of the planet's rotation suffered from inaccuracies.

To correct the error, it was necessary to “decide” that a day on Venus is equal to 243.0185 ± 0.0001 Earth days. These estimates differ markedly from those issued by Magellan. However, the researchers say they are closer to data that existed before Magellan's launch.

Why was there such a discrepancy in the data? According to experts, the length of the day can vary depending on weather cycles.

Despite the fact that the mass and dimensions of Venus are very close to those of Earth, other parameters are very different from ours. Thus, the surface temperature of the planet is about 735 degrees Kelvin, and the atmospheric pressure at the surface is almost a hundred times greater than that on Earth. It is known that the Venusian atmosphere consists of carbon dioxide with a small admixture of nitrogen, water vapor and sulfur dioxide gases. It also contains carbon monoxide, water, heavy water, hydrogen fluoride, hydrochloric acid and sulfur dioxide.

Because Venus is shrouded in 20 kilometers of sulfuric acid clouds, its surface is heated to more than 450 degrees Celsius, and its atmospheric pressure is almost 100 times higher than on Earth. But the change of seasons on the planet practically does not appear, since its axis is inclined to the solar equator by only three degrees (the Earth’s inclination is about 23 degrees). In addition, Venus’s orbit is closer to a circle than to a classic ellipse, so there are no sharp temperature changes in the planet’s atmosphere as it approaches or moves away from the Sun.

There are also no nighttime temperature changes, since the planet simply does not have time to cool down overnight - a dense atmosphere and clouds of sulfuric acid “wrap” it in a “blanket,” and winds from the part facing the Sun deliver heat. By the way, the night on Venus, due to its too slow rotation around the Sun, lasts almost two Earth months. In addition, since Venus has lost almost all its water during its evolution, there is no precipitation there.

uncle_Serg

“Catastrophic” craters without planetary explosions
Constant use of the combination“catastrophic craters” could give the false impression that I am a supporter of the theory of “explosions of planets” in ancient times (including the hypothesis of the death of the planet Phaethon). So, my like-minded person Nikkro wrote the following:
“Generally speaking, the Artifact Mechanism did not really stand on ceremony with planets, and even with satellites, just look at the photographs of the largest impact craters. Everything took place at the limit of the planets’ strength; a little more, and they could have shattered into pieces (like the hypothetical planet Phaeton). In any case, as follows from this, the most important task of the Mechanism was the task of “polishing” the orbits of the celestial bodies of the Solar System, and the damage caused to them in this case was not taken into account.
For example, Venus and Mars have changed very much as a result of these operations, and, from my point of view, not in better side. It’s good that the Earth is luckier in this regard.”(Note: “Artifact Mechanism” is what Nikkro and I call the ancient mechanism of planet formation).
I meant the word “catastrophic” to mean “destructive, having an extremely strong impact on the state of the surface.” Many impact craters actually look like classic impact craters, having a distinct single annular shaft with a hill in the center. But I never believed that such a collision was a consequence of planetary explosions in solar system, followed by a “disorderly” fall of fragments onto planets and satellites.
Purely theoretically, there is nothing “criminal” in the hypothesis of planetary explosions. But when researchers savor “planetary billiards” and describe in detail how the explosion of a particular planet (for example, Phaethon) becomes a real shock for the entire Solar System, I cannot agree with this interpretation.
When bodies of giant masses collide, in addition to damage to the surface (there is no point in denying them - they are clearly visible in photographs), the angular momentum of the planet (satellite, asteroid) must also change.

Mercury recognized as a cosmic donor

“Mercury could have been noticeably larger before some of its matter “precipitated” onto Earth and Venus after collisions with a large celestial body, suggest employees of the University of Bern. They tested the hypothetical scenario using computer simulations and found that "Protomercury" was supposed to participate in the collision, whose mass was 2.25 times the mass of the current planet, and “planetesimal”, that is, a giant asteroid, two times smaller than modern Mercury. The website “Details” reports this.

The hypothesis was supposed to explain the anomalous density of Mercury: it is known that it is noticeably greater than that of other “solid” planets, which implies that the heavy metal core is apparently surrounded by a thin mantle and crust. If the “collision” version is correct, then after the cataclysm a noticeable part of the substance, consisting mainly of silicates, should have left the planet...

Burn does not claim that this version is the only possible one, but hopes that it will be confirmed by probe data. As you know, in 2011, the NASA Messenger probe will visit the planet and build a map of the distribution of minerals on the planet’s surface.” (http://itnews.com.ua/21194.html )

“There are huge chasms on the surface of Mercury, some up to hundreds of kilometers long and up to three kilometers deep. One of the largest features on the surface of Mercury is Caloris pool. Its diameter is approximately 1300 km. It looks like large pools on the moon. Like moon pools , its appearance may have been caused by a very large collision in the early history of the Solar System». http://lenta.ru/articles/2004/08/02/mercury/

“The Caloris Basin is clearly an extensive impact formation. At the end of the crater formation era, approximately 3-4 billion years ago, huge asteroid - possibly the largest ever to hit the surface of Mercury - hit the planet" Unlike previous impacts, which only pockmarked Mercury's surface, this violent impact caused the mantle to rip apart into the planet's molten interior. A huge mass of lava gushed out from there and flooded the giant crater. The lava then froze and hardened, but the “waves” on the sea of ​​molten rock remained forever.
Apparently, the impact that shook the planet and led to the formation of the Caloris Basin had a significant impact on some other areas of Mercury. Diametrically opposite the Caloris Basin(i.e. exactly on the opposite side of the planet from him) there is a wavy area of ​​an unusual appearance. This territory is covered with thousands of closely spaced block-shaped hills with a height of 0.25- 2 km . It is natural to assume that the powerful seismic waves that arose during the impact that formed the Caloris Basin, passing through the planet, were focused on its other side. The ground vibrated and shook with such force that thousands of mountains more than a kilometer high rose in just a matter of seconds. This was apparently the most catastrophic event in the entire history of the planet.”("Mercury - spacecraft research",http://artefact.aecru.org/wiki/348/86 ). Photo: Caloris Pool. Mariner 10 photo. http://photojournal.jpl.nasa.gov/catalog/PIA03102

What do we see after a series of all these catastrophic collisions? The deviation of Mercury's axis from the perpendicular to the plane of its revolution around the Sun (axial deviation) is 0.1 degrees! Not to mention the amazing resonance mentioned at the beginning of the article:

« The movement of Mercury is coordinated with the movement of the Earth. From time to time Mercury is in inferior conjunction with the Earth. This is the name for the position when the Earth and Mercury find themselves on the same side of the Sun, lining up with it on the same straight line.

The inferior conjunction repeats every 116 days, which coincides with the time of two full rotations of Mercury and, when meeting the Earth, Mercury always faces it with the same side. But what force makes Mercury align not with the Sun, but with the Earth. Or is this an accident? » (M. Karpenko. “The Intelligent Universe.” http://karpenko-maksim.viv.ru/cont/univers/28.html ).

Despite the exotic nature of the situation, Mercury, “equal to the Earth,” rotates (albeit very slowly), still in the same direction as most of the planets of the solar system. For example, to achieve a similar resonance with the Earth, Venus would have to rotate also very slow, but V reverse side . The most amazing thing is that Venus rotates just like that.

Reverse rotation of Venus

The incomprehensibly anomalous rotation of Venus also needs explanation:

“In the 80s. XIX century Italian astronomer Giovanni Schiaparelli found that Venus rotates much more slowly. Then he assumed that the planet faces the Sun with one side, like the Moon faces the Earth, and, therefore, its rotation period is equal to the period of revolution around the Sun - 225 days. The same point of view was expressed regarding Mercury. But in both cases this conclusion turned out to be incorrect. Only in the 60s. In the 20th century, the use of radar allowed American and Soviet astronomers to prove that the rotation of Venus is reverse, that is, it rotates in the direction opposite to the direction of rotation of the Earth, Mars, Jupiter and other planets. In 1970, two groups of American scientists made observations for 1962-1969. They accurately determined that the rotation period of Venus is 243 days. Soviet radiophysicists also received similar significance. The rotation around its axis and the orbital motion of the planet determine the apparent movement of the Sun across its horizon. Knowing the periods of rotation and revolution, it is easy to calculate the length of the solar day on Venus. It turns out that they are 117 times longer than those on Earth, and the Venusian year consists of less than two such days.

Now let's assume that we are observing Venus in superior conjunction, that is, when the Sun is located between the Earth and Venus. This configuration will be repeated after 585 Earth days: being at other points in their orbits, the planets will take the same position relative to each other and the Sun. During this time, exactly five local solar days will pass on Venus (585 = 117 x 5). And this means that it will be turned towards the Sun (and therefore towards the Earth) with the same side as at the time of the previous conjunction. This mutual motion of the planets is called resonant; it is apparently caused by the long-term influence of the Earth's gravitational field on Venus. That is why astronomers of the past and the beginning of this century believed that Venus always faces the Sun with one side.” http://planets2001.narod.ru/venvr.html

“The direction of rotation of Venus around its axis is reverse, that is, opposite to the direction of its rotation around the Sun. For all other planets (excluding Uranus), including our Earth, the direction of rotation is direct, that is, it coincides with the direction of rotation of the planet around the Sun...
It is interesting to note that the rotation period of Venus is very close to the period of the so-called resonant rotation of the planet relative to the Earth, equal to 243.16 Earth days. During the resonant rotation between each inferior and superior conjunction, Venus makes exactly one revolution relative to the Earth, and therefore at the conjunction it faces the Earth with the same side." (A.D. Kuzmin. “Planet Venus”, p. 38).Venusno way could not form from a protoplanetary cloud, having a reverse rotation, - therefore, she changed the direction of rotation later . This is not to say that scientists have not tried to come up with anything to explain this phenomenon. But their models turned out to be confusing and contradictory:
“Based on a systematic analysis of the facts related to this issue, we state that Venus faces the Earth always with the same side during the era of inferior conjunction, as well as its retrograde rotation are a consequence of the law of gravity acting between the Earth and the “displacement of the center of the figure of Venus relative to the center of mass by 1.5 km in the direction of the Earth.” http://muz1.narod.ru/povenvrobr.htm . «… During an inferior conjunction (i.e., when the distance between Venus and Earth is minimal), Venus always faces the Earth with the same side...
Mercury also has this feature... If the slow rotation of Mercury can still be explained by the action of solar tides, then the same the explanation for Venus faces significant difficulties... It is hypothesized that Venus was slowed down by Mercury, which was once its satellite...
Just as in the case of the Earth-Moon system, at first the current two inner planets formed a very close pair with rapid axial rotation. Due to the tides, the distance between the planets increased and the axial rotation slowed down. When the semi-major axis of the orbit reached approx. 500 thousand km, this pair “broke”, i.e. the planets ceased to be gravitationally bound... The separation of the Earth-Moon pair did not occur due to the relatively small mass of the Moon and the greater distance to the Sun. As a trace of these long-past events, a significant eccentricity of Mercury's orbit remained and common orientation of Venus and Mercury in inferior conjunction. This hypothesis also explains the lack of satellites of Venus and Mercury and the complex topography of Venus's surface, which can be explained by the deformation of its crust by powerful tidal forces from the rather massive Mercury." (I. Shklovsky. “The Universe, Life, Mind.” 6th ed., 1987, p. 181).“Not so long ago, on the pages of the scientific press, the question was discussed about Wasn't Mercury a satellite of Venus in the past?, then moving under the influence of the powerful gravitational attraction of the Sun into orbit around it. If Mercury was indeed previously a satellite of Venus, then even earlier it must have moved to the orbit of Venus from an orbit around the Sun, located between the orbits of Venus and the Earth. Having greater relative braking than Venus, Mercury could come close to it and move into its orbit, while changing the direct direction of rotation to the reverse. Mercury could not only stop the slow and direct axial rotation of Venus under the influence of tidal friction, but also force it to slowly rotate in the opposite direction. Thus, Mercury automatically changed the direction of its circulation relative to Venus to direct, and Venus approached the Sun. As a result of capture by the Sun, Mercury returned to its circumsolar orbit, ending up ahead of Venus. However, a number of questions arise here that need to be resolved. Question one: why was Mercury able to force Venus to rotate in the opposite direction, but Charon was unable to force Pluto to rotate in the opposite direction? After all, the ratio of their masses is approximately the same - 15:1. This question can still be answered somehow, for example, by assuming that Venus had another large satellite like the moon which, having approached under the influence of tidal friction(as Phobos and Triton are now approaching their planets) to the surface of Venus, crashed onto it and, transferring its angular momentum to Venus, caused it to rotate in the opposite direction, since this hypothetical satellite orbited Venus in the opposite direction.
But a second, more serious question arises: if Mercury was a satellite of Venus, it should not be moving away from Venus, like the Moon from the Earth, but approaching it, since, firstly, Venus rotates slowly and its rotation period would be less than its orbital period Mercury, secondly, Venus rotates in the opposite direction. However, the answer can also be found here, for example, by assuming that the second satellite, falling on the surface of Venus, caused it to rapidly rotate in the opposite direction, so that the period of rotation of Venus became less than the period of revolution of Mercury, which, as a result, began to move away from it faster and, having gone beyond the sphere of influence of Venus, moved into a circumsolar orbit...” (M.V. Grusha. Abstract “The Origin and Development of the Solar System”). http://artefact.aecru.org/wiki/348/81

Not very convincing. And yet, again and again, scientists resort to their favorite “catastrophic” scenarios:

“The long-known phenomenon - the absence of a natural satellite for the planet Venus - is explained in their own way by young scientists at the California Institute of Technology (Caltech). “The model, presented last Monday at the Division for Planetary Sciences conference in Pasadena by Alex Alemi and Caltech fellow David Stevenson, suggests that Venus once had a satellite, but it split apart. There is one more planet in the solar system without a satellite - Mercury (there was once a version put forward that it is former companion Venus). And it, like Venus, rotates slowly, and this fact, as well as the absence of a magnetic field on Venus and the extremely weak magnetic field of Mercury, were considered the main explanation for the mysterious phenomenon that Californian planetary scientists paid attention to. Venus completes a full revolution around its axis in 243 Earth days, but, according to the authors of the model, this is not the only thing. Unlike Earth and other planets, Venus rotates clockwise when viewed from the planet's north pole. And this may be evidence that she suffered not one, but two strong collisions - the first knocked the satellite out of her, and from the second the satellite itself, which had been knocked out earlier, suffered.
According to Alemi and Stevenson, from the first impact, Venus spun counterclockwise, and the piece knocked out of it became a satellite, just as our Moon was formed from the collision of the Earth with a celestial body the size of Mars. The second blow returned everything to its place, and Venus began to spin clockwise, as it does now. However, solar gravity contributed to slowing down the rotation of Venus and even reversing the direction of its motion. This circulation, in turn, influenced the gravitational interactions between the satellite and the planet, as a result of which the satellite began to move inward, as it were, i.e. approaching a planet with an inevitable collision with it. The second collision could also have produced a satellite, or it might not have arisen, notes the ScientificAmerican.com newswire, which reported on the Alemi-Stevenson model. And this hypothetical satellite, if it had arisen, could have been blown to pieces by the first satellite falling on the planet. According to Stevenson, their model can be tested by looking at isotopic signatures in Venusian rock - their exotic nature could be interpreted as evidence of a collision with a foreign celestial body." (“Why Doesn’t Venus Have a Moon?”http://www.skyandtelescope.com/news/4353026.html ).

It is clear why the authors of the hypothesis needed such a complex scenario. Indeed, the first collision should have led to a random rotation of Venus, and only the second “impact” could give it its current rotation. Another thing is that in order to achieve resonance with the Earth, the force, direction and angle of the impacts had to be calculated so accurately that Alemi and Stevenson are resting. How “filigree” the adjustment of the resonant rotation of Venus relative to the Earth is possible, based on random factors - judge for yourself.

No matter what cataclysms and “explosions of planets” shook the Solar System in the past, I want to state: without careful and subtle adjustments simultaneously for the two planets of the Solar System (Venus and Mercury), such a resonance will not be “tuned” in any way. And the fact that such an adjustment is carried out by a powerful and, most importantly, reasonable force is obvious to me.

As for the almost “zero” axial deflection of Mercury, it led to a very interesting result.

Extraordinarily high reflection of radio waves by Mercury's polar regions

“Probing of Mercury with radars from Earth showed unusually high reflection of radio waves by the polar regions of Mercury. What is this, ice, as the popular explanation says? No one knows.
But where does ice come from on the planet closest to the Sun, where daytime temperatures at the equator reach 400 degrees Celsius? The fact is that in the region of the poles, in craters, where they never get Sun rays temperature – 200. And ice brought by comets could well have been preserved there.” (skyer.ru/planets/mercury/articles/mercu ry_transit.htm).

“Radar studies of the planet’s circumpolar regions have shown the presence there of a substance that strongly reflects radio waves, the most likely candidate for which is ordinary water ice. Entering the surface of Mercury when comets hit it, water evaporates and travels around the planet until it freezes in the polar regions at the bottom of deep craters, where the Sun never looks, and where ice can persist almost indefinitely.” (“Mercury. Physical characteristics.” athens.kiev.ua/pages/solarsystem/korchin skiy/Mercuri/m%20fh.htm).

“It would seem absurd to talk about the possibility of the existence of ice on Mercury. But in 1992, during radar observations from the Earth near the north and south poles of the planet, areas that very strongly reflect radio waves were discovered for the first time. It was these data that were interpreted as evidence of the presence of ice in the near-surface layer of Mercury. Radar measurements from the Arecibo radio observatory located on the island of Puerto Rico, as well as from the NASA Deep Space Communications Center in Goldstone (California) revealed about 20 round spots several tens of kilometers across with increased radio reflection. Presumably these are craters, into which, due to their close location to the poles of the planet, the sun's rays fall only briefly or not at all. Such craters, called permanently shadowed ones, are also present on the Moon; measurements from satellites have revealed the presence of some amount of water ice in them. Calculations have shown that in the depressions of permanently shadowed craters at the poles of Mercury it can be cold enough (–175 ° C) for ice to exist there for a long time. Even in flat areas near the poles, the estimated daily temperature does not exceed –105°C. There are still no direct measurements of the surface temperature of the polar regions of the planet.

Despite observations and calculations, the existence of ice on the surface of Mercury or at a small depth beneath it has not yet received unambiguous evidence, since Rocks containing compounds of metals with sulfur also have increased radio reflection, and possible metal condensates on the surface of the planet, for example, sodium ions deposited on it as a result of the constant “bombardment” of Mercury by particles solar wind.

But here the question arises: why is the distribution of areas that strongly reflect radio signals clearly confined specifically to the polar regions of Mercury? Maybe the rest of the territory is protected from the solar wind by the planet's magnetic field? Hopes for clarifying the mystery of ice in the kingdom of heat are connected only with the flight to Mercury of new automatic space stations equipped measuring instruments, allowing us to determine the chemical composition of the planet’s surface.” (“Around the World”, No. 12 (2759), December 2003. vokrugsveta.ru/publishing/vs/archives/?i tem_id=625). Photo of Mercury's south pole. Mariner 10 photo. http://photojournal.jpl.nasa.gov/catalog/PIA02941

The point is not even the fact of the existence of ice. Obviously, the poles of Mercury are an ideal place for the possible location of artifacts sensitive to high temperatures. If ice has been preserved on the planet for many millions of years, then could the active elements of the “Artifact Mechanism” remain there?

I think that's the point one of the reasons the painful “polishing” of its orbit for Mercury by the ancient mechanism of planet formation. If the planet's axial deviation exceeded 0.1 degrees, seasonal temperature fluctuations would inevitably occur in the protected areas of Mercury, and the “protected areas” would not be able to survive for millions of years. No other planet in the Solar System has such a strict perpendicular to the rotation axis to the orbital plane. Think, it is at the poles of Mercury that the active elements of the “Artifact Mechanism” can be found. It was not for nothing that the authors of the article in the magazine “Around the World” pointed out that not only ice, but also metal has increased radio reflection. Well, let's wait until 2011 for answers.

Second reason changes in the orbit of Mercury, like Venus, were orientation to the Earth in the lower connection. It would be interesting to know what relief details are located in the center of the disk of these planets during inferior conjunction with the Earth. Perhaps these objects hide artifacts of the Forerunners (the conventional name for the creators of the ancient mechanism of planet formation), left by them in ancient times to observe (possibly and not only) the Earth.
("The mechanism of artificial intervention in the formation of the Solar system." Internet research results "An Artifact Called Solar System",http://artefact.aecr u.org/wiki/393/116 ). Photo of Venus. http://www.solarviews.com/browse/venus/venus2.jpg

Light stripes in the area South Pole Mercury

“A field of bright rays-created by ejecta from a crater-radiating to the north (top) from off camera (lower right) is seen in this view of Mercury taken 1975, September 21 by “Mariner 10”.Source of the rays is a large new crater to the south, near Mercury's South Pole. "Mariner 10" was about 48,000 kilometers (30,000 miles) from Mercury when the picture (FDS 166749) was taken at 2:01 p.m. PDT, just three minutes after the spacecraft was closest to the planet. Largest crater in this picture is 100 kilometers (62 miles) in diameter."

The second planet from the Sun, Venus, is the closest to Earth and, perhaps, the most beautiful of the planets terrestrial group. For thousands of years she has attracted curious glances from scientists of ancient and modern times to mere mortal poets. No wonder she has the name greek goddess love. But its study rather adds questions than gives any answers.

One of the first observers, Galileo Galilei, observed Venus with a telescope. With the advent of more powerful optical devices such as telescopes in 1610, people began to observe the phases of Venus, which closely resembled the phases of the moon. Venus is one of the brightest stars in our sky, so at dusk and in the morning, you can see the planet with the naked eye. Watching its passage in front of the Sun, Mikhailo Lomonosov in 1761 examined a thin rainbow rim surrounding the planet. This is how the atmosphere was discovered. It turned out to be very powerful: the pressure near the surface reached 90 atmospheres!
The greenhouse effect explains the high temperatures of the lower layers of the atmosphere. It is also present on other planets, for example on Mars, due to it, the temperature can rise by 9°, on Earth - up to 35°, and on Venus - it reaches its maximum, among planets - up to 480° C.

Internal structure of Venus

The structure of Venus, our neighbor, is similar to other planets. It includes the crust, mantle and core. The radius of the liquid core containing a lot of iron is approximately 3200 km. The structure of the mantle - molten matter - is 2800 km, and the thickness of the crust is 20 km. It is surprising that with such a core, the magnetic field is practically absent. This is most likely due to the slow rotation. The atmosphere of Venus reaches 5500 km, the upper layers of which consist almost entirely of hydrogen. The Soviet automatic interplanetary stations (AMS) Venera-15 and Venera-16 back in 1983 discovered mountain peaks with lava flows on Venus. Now the number of volcanic objects reaches 1600 pieces. Volcanic eruptions indicate activity in the planet's interior, which is locked under thick layers of basalt shell.

Rotation around its own axis

Most of the planets in the solar system rotate around their axis from west to east. Venus, like Uranus, is an exception to this rule, and rotates in the opposite direction, from east to west. This non-standard rotation is called retrograde. Thus, full turn around its axis, lasts 243 days.

Scientists believe that after the formation of Venus, there was a large number of water. But, with the advent of the greenhouse effect, the evaporation of the seas began and the release of carbon dioxide anhydrite, which is part of various rocks, into the atmosphere. This led to an increase in water evaporation and an overall increase in temperature. After some time, the water disappeared from the surface of Venus and entered the atmosphere.

Now, the surface of Venus looks like a rocky desert, with occasional mountains and undulating plains. From the oceans, only huge depressions remained on the planet. Radar data taken from interplanetary stations recorded traces of a recent volcanic activity.
In addition to the Soviet spacecraft, the American Magellan also visited Venus. He produced an almost complete mapping of the planet. During the scanning process, a huge number of volcanoes, hundreds of craters and numerous mountains were discovered. Based on their characteristic elevations, relative to the average level, scientists have identified 2 continents - the land of Aphrodite and the land of Ishtar. On the first continent, the size of Africa, there is an 8-kilometer Mount Maat - a huge extinct volcano. The continent of Ishtar is comparable in size to the United States. Its attraction is the 11-kilometer Maxwell Mountains, the highest peaks on the planet. The composition of the rocks resembles terrestrial basalt.
On the Venusian landscape, impact craters filled with lava can be found with a diameter of about 40 km. But this is an exception, because there are about 1 thousand of them in total.

Characteristics of Venus

Weight: 4.87*1024 kg (0.815 earth)
Diameter at the equator: 12102 km
Axle tilt: 177.36°
Density: 5.24 g/cm3
Average surface temperature: +465 °C
Period of rotation around the axis (days): 244 days (retrograde)
Distance from the Sun (average): 0.72 a. e. or 108 million km
Orbital period around the Sun (year): 225 days
Orbital speed: 35 km/s
Orbital eccentricity: e = 0.0068
Orbital inclination to the ecliptic: i = 3.86°
Gravity acceleration: 8.87m/s2
Atmosphere: carbon dioxide (96%), nitrogen (3.4%)
Satellites: no

>> Rotation axis of Venus

Rotation of Venus around its axis: description of the axis of an inverted planet with a photo, retrograde Venus, comparison with the Earth, seasons, counterclockwise rotation.

You will be surprised, but the tilt of Venus’s axis reaches 177.3°. Yes, it seems too strange, so let's figure it out. The Earth's index is 23.5°. This leads to the formation of the seasons, so we expect Venus' rotation axis to create some real madness there.

Oh no. Let's brush up on your geometry knowledge a little. A full circle is 360° and half a circle is 180°. So if we subtract 177.3° from 180°, we get 2.7°. In fact, this is how Venus is tilted relative to the solar system's ecliptic plane because it is perfectly inverted.

Venus is unique because it is the only one among solar planets rotates in the opposite direction (Venus retrograde). If you observe from above, then everyone rotates counterclockwise, and Venus follows it.

Perhaps everything on the planet turned upside down due to a strong blow in the past. Or Venus has slowed down due to tidal locking with our star.

We know that the axis is responsible on Earth for the change of seasons. Winter comes to the northern hemisphere when the north pole is tilted away from sunlight. In summer the situation changes. Devoid of seasonality, Venus is forced to exist with a constant temperature heating of 462°C.

And the third brightest object in the sky after the Sun and Moon. This planet is sometimes called sister of the earth, which is associated with a certain similarity in weight and size. The surface of Venus is covered with a completely impenetrable layer of clouds, the main component of which is sulfuric acid.

Naming Venus The planet was named after the Roman goddess of love and beauty. Back in the days of the ancient Romans, people already knew that this Venus is one of four planets different from Earth. It was the planet's highest luminosity, the prominence of Venus, that played a role in its being named after the goddess of love, and this allowed the planet to be associated with love, femininity and romance for years.

For a long time it was believed that Venus and Earth are twin planets. The reason for this was their similarity in size, density, mass and volume. However, later scientists found out that despite the obvious similarity of these planetary characteristics, the planets are very different from each other. We are talking about such parameters as atmosphere, rotation, surface temperature and the presence of satellites (Venus does not have them).

As with Mercury, humanity's knowledge of Venus increased significantly in the second half of the twentieth century. Before the US and Soviet Union began organizing their missions in the 1960s, scientists still had hope that the conditions beneath Venus's incredibly dense clouds might be suitable for life. But the data collected as a result of these missions proved the opposite - the conditions on Venus are too harsh for living organisms to exist on its surface.

A significant contribution to the study of both the atmosphere and surface of Venus was made by the USSR mission of the same name. The first spacecraft sent to the planet and to fly past the planet was Venera-1, developed by the S.P. Rocket and Space Corporation Energia. Korolev (today NPO Energia). Despite the fact that communication with this ship, as well as with several other mission vehicles, was lost, there were those that were able not only to study the chemical composition of the atmosphere, but even to reach the surface itself.

The first spacecraft, launched on June 12, 1967, that was able to conduct atmospheric research was Venera 4. The spacecraft's descent module was literally crushed by pressure in the planet's atmosphere, but the orbital module managed to complete whole line the most valuable observations and obtain the first data on Venus’s temperature, density and chemical composition. The mission determined that the planet's atmosphere consists of 90% carbon dioxide with minor amounts of oxygen and water vapor.

The orbiter's instruments indicated that Venus has no radiation belts, and a magnetic field 3000 times weaker than the Earth's magnetic field. An indicator of ultraviolet radiation from the Sun on board the ship revealed the hydrogen corona of Venus, the hydrogen content of which was approximately 1000 times less than in the upper layers of the Earth's atmosphere. The data were later confirmed by the Venera 5 and Venera 6 missions.

Thanks to these and subsequent studies, today scientists can distinguish two broad layers in the atmosphere of Venus. The first and main layer is the clouds, which cover the entire planet in an impenetrable sphere. The second is everything below those clouds. The clouds surrounding Venus extend from 50 to 80 kilometers above the planet's surface and consist mainly of sulfur dioxide (SO2) and sulfuric acid (H2SO4). These clouds are so dense that they reflect 60% of all the sunlight Venus receives back into space.

The second layer, which is below the clouds, has two main functions: density and composition. The combined effect of these two functions on the planet is enormous - it makes Venus the hottest and least hospitable of all the planets in the solar system. Due to the greenhouse effect, the temperature of the layer can reach 480°C, which allows the surface of Venus to be heated to the maximum temperatures in our system.

Clouds of Venus

Using observations from the European Space Agency's (ESA) Venus Express satellite, scientists have been able to show for the first time how weather conditions in Venus' thick cloud layers are linked to its surface topography. It turned out that the clouds of Venus can not only prevent observation of the surface of the planet, but also give clues about what exactly is located on it.

It is believed that Venus is very hot due to the incredible greenhouse effect that heats its surface to temperatures of 450 degrees Celsius. The climate on the surface is depressing, and it itself is very dimly lit, as it is covered with an incredibly thick layer of clouds. At the same time, the wind that is present on the planet has a speed not exceeding the speed of an easy jog - 1 meter per second.

However, when viewed from afar, the planet, which is also called Earth's sister, looks very different - smooth, bright clouds surround the planet. These clouds form a thick twenty-kilometer layer that lies above the surface and is thus much colder than the surface itself. The typical temperature of this layer is about -70 degrees Celsius, which is comparable to temperatures on the cloud tops of the Earth. In the cloud's upper layer, weather conditions are much more extreme, with winds blowing hundreds of times faster than on the surface and even faster than the rotation speed of Venus itself.

With the help of Venus Express observations, scientists were able to significantly improve the climate map of Venus. They were able to identify three aspects of the planet's cloudy weather: how quickly the winds on Venus can circulate, how much water is contained in the clouds, and how bright these clouds are distributed across the spectrum (in ultraviolet light).

“Our results showed that all these aspects: wind, water content and cloud composition are somehow related to the properties of the surface of Venus itself,” said Jean-Loup Berto of the LATMOS Observatory in France, lead author of the new Venus Express study. "We used observations from the spacecraft that spanned a period of six years, from 2006 to 2012, and this allowed us to study patterns of long-term weather change on the planet."

Surface of Venus

Before radar studies of the planet, the most valuable data on the surface was obtained with the help of the same Soviet space program "Venus". The first vehicle to make a soft landing on the surface of Venus was the Venera 7 space probe, launched on August 17, 1970.

Despite the fact that even before landing, many of the ship’s instruments were already out of order, he was able to identify pressure and temperature indicators on the surface, which amounted to 90 ± 15 atmospheres and 475 ± 20 ° C.

1 – descent vehicle;
2 – solar panels;
3 – celestial orientation sensor;
4 – protective panel;
5 – corrective propulsion system;
6 – pneumatic system manifolds with control nozzles;
7 – cosmic particle counter;
8 – orbital compartment;
9 – radiator-cooler;
10 – low-directional antenna;
11 – highly directional antenna;
12 – pneumatic system automation unit;
13 – compressed nitrogen cylinder

The subsequent mission "Venera 8" turned out to be even more successful - it was possible to obtain the first surface soil samples. Thanks to the gamma spectrometer installed on the ship, it was possible to determine the content of radioactive elements such as potassium, uranium, and thorium in the rocks. It turned out that the soil of Venus resembles terrestrial rocks in its composition.

The first black-and-white photographs of the surface were taken by the Venera 9 and Venera 10 probes, which were launched almost one after the other and soft-landed on the surface of the planet on October 22 and 25, 1975, respectively.

After this, the first radar data of the Venusian surface were obtained. The pictures were taken in 1978, when the first of the American spacecraft Pioneer Venus arrived in orbit of the planet. Maps created from the images showed that the surface consists mainly of plains, the formation of which is caused by powerful lava flows, as well as two mountainous regions, called Ishtar Terra and Aphrodite. The data was subsequently confirmed by the Venera 15 and Venera 16 missions, which mapped the planet's northern hemisphere.

The first color images of the surface of Venus and even recordings of sound were obtained using the Venera 13 lander. The module's camera took 14 color and 8 black and white photographs of the surface. Also, an X-ray fluorescence spectrometer was used for the first time to analyze soil samples, which made it possible to identify the priority rock at the landing site - leucite alkali basalt. The average surface temperature during module operation was 466.85 °C and the pressure was 95.6 bar.

The module launched after the Venera-14 spacecraft was able to transmit the first panoramic images of the planet’s surface:

Despite the fact that the photographic images of the planet’s surface obtained with the help of the Venus space program are still the only and unique ones and represent the most valuable scientific material, these photographs could not give a large-scale idea of ​​the planet’s topography. After analyzing the results obtained, the space powers focused on radar research of Venus.

In 1990, he began his work in orbit of Venus spacecraft called Magellan. He managed to take better radar images, which turned out to be much more detailed and informative. For example, it turned out that of the 1,000 impact craters that Magellan discovered, not a single one was larger than two kilometers in diameter. This led scientists to believe that any meteorite with a diameter of less than two kilometers simply burned up when passing through the dense Venusian atmosphere.

Due to the thick clouds that shroud Venus, details of its surface cannot be seen using simple photographic means. Fortunately, scientists were able to use the radar method to obtain the necessary information.

While both photography and radar work by collecting radiation that bounces off an object, they have a big difference in how they reflect forms of radiation. Photography captures visible light, while radar mapping captures microwave radiation. The advantage of using radar in the case of Venus was obvious, since microwave radiation can pass through the planet's thick clouds, whereas the light needed for photography is not able to do this.

Thus, additional studies of crater sizes have helped shed light on factors that indicate the age of the planet's surface. It turned out that small impact craters are practically absent on the surface of the planet, but there are also no craters of large diameter. This led scientists to believe that the surface was formed after a period of heavy bombardment between 3.8 and 4.5 billion years ago, when large numbers of impact craters were formed on the inner planets. This indicates that the surface of Venus has a relatively small geological age.

The study of the planet's volcanic activity revealed even more characteristic features of the surface.

The first feature is the huge plains described above, created by lava flows in the past. These plains cover about 80% of the entire Venusian surface. Second characteristic feature are volcanic formations that are very numerous and diverse. In addition to shield volcanoes that also exist on Earth (for example, Mauna Loa), many flat volcanoes have been discovered on Venus. These volcanoes are different from those on Earth because they have a distinctive flat disc-shaped shape due to the fact that all the lava contained in the volcano erupted at once. After such an eruption, the lava comes out in a single stream, spreading in a circular manner.

Geology of Venus

As with other terrestrial planets, Venus is essentially made up of three layers: crust, mantle and core. However, there is something that is very intriguing - the interior of Venus (unlike or) is very similar to the interior of the Earth. Due to the fact that it is not yet possible to compare the true composition of the two planets, such conclusions were made based on their characteristics. It is currently believed that Venus' crust is 50 kilometers thick, its mantle 3,000 kilometers thick, and its core 6,000 kilometers in diameter.

In addition, scientists still do not have an answer to the question of whether the planet’s core is liquid or is solid. All that remains is to assume, in view of the similarity of the two planets, that it is the same liquid as that of the Earth.

However, some studies indicate that Venus's core is solid. To prove this theory, researchers cite the fact that the planet significantly lacks a magnetic field. In other words, planetary magnetic fields are the result of heat transfer from inside the planet to its surface, and a necessary component of this transfer is the liquid core. The insufficient strength of magnetic fields, according to this concept, indicates that the existence of a liquid core on Venus is simply impossible.

Orbit and rotation of Venus

The most remarkable aspect of Venus's orbit is its uniform distance from the Sun. The orbital eccentricity is only .00678, which means that Venus's orbit is the most circular of all the planets. Moreover, such a small eccentricity indicates that the difference between Venus's perihelion (1.09 x 10 8 km) and its aphelion (1.09 x 10 8 km) is only 1.46 x 10 6 kilometers.

Information about the rotation of Venus, as well as data about its surface, remained a mystery until the second half of the twentieth century, when the first radar data were obtained. It turned out that the planet's rotation around its axis is counterclockwise when viewed from the "upper" plane of the orbit, but in fact Venus's rotation is retrograde, or clockwise. The reason for this is currently unknown, but there are two popular theories that explain this phenomenon. The first indicates a 3:2 spin-orbit resonance of Venus with the Earth. Proponents of the theory believe that over billions of years, Earth's gravity changed the rotation of Venus to its current state.

Proponents of another concept doubt that Earth's gravitational force was strong enough to change Venus's rotation in such a fundamental way. Instead they refer to early period existence of the solar system, when the formation of planets took place. According to this view, Venus's original rotation was similar to that of the other planets, but was changed to its current orientation by the collision of the young planet with a large planetesimal. The collision was so powerful that it turned the planet upside down.

The second unexpected discovery related to the rotation of Venus is its speed.

In order to make a full revolution around its axis, the planet requires about 243 Earth days, that is, a day on Venus is longer than on any other planet and a day on Venus is comparable to a year on Earth. But even more scientists were struck by the fact that a year on Venus is almost 19 Earth days less than one day on Venus. Again, no other planet in the solar system has such properties. Scientists associate this feature precisely with the reverse rotation of the planet, the features of the study of which were described above.

• Venus is the third brightest natural object in the Earth's sky after the Moon and the Sun. The planet has a visual magnitude of -3.8 to -4.6, making it visible even on a clear day.
  Venus is sometimes called " morning star" and "evening star". This is due to the fact that representatives of ancient civilizations mistook this planet for two different stars, depending on the time of day.
  One day on Venus is longer than one year. Due to the slow rotation around its axis, a day lasts 243 Earth days. A revolution around the planet's orbit takes 225 Earth days.
  Venus is named after the Roman goddess of love and beauty. It is believed that the ancient Romans named it this way because of the planet's high brightness, which in turn may have come from the times of Babylon, whose inhabitants called Venus "the bright queen of the sky."
  Venus has no satellites or rings.
  Billions of years ago, Venus' climate may have been similar to Earth's. Scientists believe Venus once had abundant water and oceans, but high temperatures and the greenhouse effect have boiled away the water and the planet's surface is now too hot and hostile to support life.
  Venus rotates in opposite direction in relation to other planets. Most other planets rotate counterclockwise on their axis, but Venus, like Venus, rotates clockwise. This is known as retrograde rotation and may have been caused by an impact with an asteroid or other space object that changed the direction of its rotation.
  Venus is the hottest planet in the solar system with an average surface temperature of 462°C. Additionally, Venus does not have a tilt on its axis, which means the planet has no seasons. The atmosphere is very dense and contains 96.5% carbon dioxide, which traps heat and causes Greenhouse effect, which evaporated water sources billions of years ago.
  The temperature on Venus practically does not change with the change of day and night. This occurs due to the solar wind moving too slowly across the entire surface of the planet.
  The age of the Venusian surface is about 300-400 million years. (The age of the Earth's surface is about 100 million years.)
  The atmospheric pressure on Venus is 92 times stronger than on Earth. This means that any small asteroids entering Venus's atmosphere will be crushed by the enormous pressure. This explains the absence of small craters on the surface of the planet. This pressure is equivalent to the pressure at a depth of about 1000 km. in the oceans of the Earth.

Venus has a very weak magnetic field. This surprised scientists, who had expected Venus to have a magnetic field similar in strength to Earth's. One possible reason for this is that Venus has a solid inner core or that it does not cool.
Venus is the only planet in the solar system named after a woman.
Venus is the closest planet to Earth. The distance from our planet to Venus is 41 million kilometers.

Photos of Venus

The first and only photographic photographs of the surface of Venus to date were obtained spaceships Soviet space program "Venus". But there are also images of the planet obtained by the Akatsuki probe.

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