Project name

Sashchenko O.

Troyanova A.

Group Research Topic

Why do planets move around the Sun?

Problematic question (research question)

Where does the Universe end?

Objectives of the study

1. Determine the main characteristics of the Universe;

2. Explore the relationship between planets and stars in the solar system.

Research results

How was the Solar System formed?

Scientists have found that the solar system was formed 4.5682 billion years ago - almost two million years earlier than previously thought, allowing astronomers to take a new look at the mechanisms of formation of our planetary system, according to a paper published in the journal Nature .

In particular, the shift in the date of birth solar system 0.3-1.9 million years back in time means that the protoplanetary cloud of matter from which the planets orbiting the intensifying star were formed contained twice as much of the rare isotope iron-60 as previously thought.

The only source of this element in the Universe are supernovae, and therefore scientists now have every reason to claim that the Solar system was born as a result of a series of supernova explosions in close proximity to each other, and not as a result of condensation from an isolated gas and dust cloud, as was previously believed quite recently.

"With this work, we are able to paint a very coherent and exciting picture of a very dynamic period in the history of the solar system," said David Kring of NASA's Lunar and Planetary Institute in Houston, as quoted by Nature News.

The beginning of the existence of the Solar System is considered to be the appearance of the first solid particles in it, rotating in a gas and dust cloud around the nascent star. The main source of knowledge about such particles comes from mineral inclusions in a special type of meteorite called chondrites. These meteorites, according to the dominant theory in cosmology, in their own way chemical composition reflect the distribution of elements and substances in the protoplanetary gas and dust disk of the early Solar System.

The oldest mineral inclusions in them are enriched in calcium and aluminum, and it is the age of these inclusions, according to theory, that should reflect the age of the Solar System.

The main achievement of the team of authors of the new publication, Audrey Bouvier and her mentor Professor Meenakshi Wadhwa from the University of Arizona, is the precise dating of the age of such an inclusion in a chondritic meteorite discovered in the Sahara Desert.

To do this, the scientists used two different techniques based on the isotope ratio of lead, as well as the isotope ratio of aluminum and magnesium. The authors of the article not only managed to identify the most “ancient” age of this inclusion compared to all objects hitherto known to scientists - 4.5682 billion years - but also for the first time brought the chronometric scales of these two dating methods into line.

The fact is that dating by lead isotopes, although considered reliable, does not allow one to obtain a sufficiently accurate age of a particular geological object. Using magnesium and aluminum isotope dating, this age can be determined with much greater accuracy, but until recently this type of dating consistently showed objects to be a million years older than lead isotope dating.

Why do planets revolve around the Sun?

There is an invisible force that makes the planets revolve around the sun. It is called the force of gravity.

Polish scientist Nikolai Copernicus was the first to discover that the orbits of the planets form circles around the Sun.

Galileo Galilei agreed with this hypothesis and proved it through observations.

In 1609, Johannes Kepler calculated that the orbits of the planets are not circular, but elliptical, with the Sun located at one of the focuses of the ellipse. He also established the laws by which this rotation occurs. They were later called Kepler's Laws.

Then the English physicist Isaac Newton discovered the law of universal gravitation and, based on this law, explained how the solar system maintains its shape constant.

Each particle of matter that makes up the planets attracts others. This phenomenon is called gravity.

Thanks to gravity, each planet in the solar system rotates in its orbit around the Sun and cannot fly into outer space.

The orbits are elliptical, so the planets either approach the Sun or move away from it.

Conclusions

The planets orbiting the Sun make up the Solar System. The sun attracts the planets, and this force of attraction holds the planets as if they were tied to a string.

Space has long attracted people's attention. Astronomers began studying the planets of the Solar System back in the Middle Ages, examining them through primitive telescopes. But a thorough classification and description of the structural features and movements of celestial bodies became possible only in the 20th century. With the advent of powerful equipment equipped with last word technology of observatories and spacecraft, several previously unknown objects were discovered. Now every schoolchild can list all the planets of the solar system in order. A space probe has landed on almost all of them, and so far man has only visited the Moon.

What is the Solar System

The Universe is huge and includes many galaxies. Our Solar System is part of a galaxy containing more than 100 billion stars. But there are very few that are like the Sun. Basically, they are all red dwarfs, which are smaller in size and do not shine as brightly. Scientists have suggested that the solar system was formed after the emergence of the Sun. Its huge field of attraction captured a gas-dust cloud, from which, as a result of gradual cooling, particles of solid matter formed. Over time, celestial bodies were formed from them. It is believed that the Sun is now in the middle of its life path, therefore, it, as well as all the celestial bodies dependent on it, will exist for several more billions of years. Near space has been studied by astronomers for a long time, and any person knows what planets of the solar system exist. Photos of them taken from space satellites can be found on the pages of various information resources devoted to this topic. All celestial bodies are held by the strong gravitational field of the Sun, which makes up more than 99% of the volume of the Solar System. Large celestial bodies rotate around the star and around its axis in one direction and in one plane, which is called the ecliptic plane.

Planets of the Solar System in order

In modern astronomy, it is customary to consider celestial bodies starting from the Sun. In the 20th century, a classification was created that includes 9 planets of the solar system. But recent space exploration and newest discoveries prompted scientists to revise many provisions in astronomy. And in 2006, at an international congress, due to its small size (a dwarf with a diameter not exceeding three thousand km), Pluto was excluded from the number of classical planets, and there were eight of them left. Now the structure of our solar system has taken on a symmetrical, slender appearance. It includes the four terrestrial planets: Mercury, Venus, Earth and Mars, then comes the asteroid belt, followed by the four giant planets: Jupiter, Saturn, Uranus and Neptune. On the outskirts of the solar system there is also a space that scientists call the Kuiper Belt. This is where Pluto is located. These places are still little studied due to their remoteness from the Sun.

Features of the terrestrial planets

What allows us to classify these celestial bodies as one group? Let us list the main characteristics of the inner planets:

• relatively not large sizes;
• hard surface, high density and similar composition (oxygen, silicon, aluminum, iron, magnesium and other heavy elements);
• presence of atmosphere;
• identical structure: a core of iron with nickel impurities, a mantle consisting of silicates, and a crust of silicate rocks (except for Mercury - it has no crust);
• a small number of satellites - only 3 for four planets;
• rather weak magnetic field.

Features of the giant planets

As for the outer planets, or gas giants, they have the following similar characteristics:

• large sizes and weights;
• they do not have a solid surface and consist of gases, mainly helium and hydrogen (therefore they are also called gas giants);
• liquid core consisting of metallic hydrogen;
• high rotation speed;
• a strong magnetic field, which explains the unusual nature of many processes occurring on them;
• there are 98 satellites in this group, most of which belong to Jupiter;
• the most characteristic feature gas giants are the presence of rings. All four planets have them, although they are not always noticeable.

The first planet is Mercury

It is located closest to the Sun. Therefore, from its surface the star appears three times larger than from the Earth. This also explains the strong temperature changes: from -180 to +430 degrees. Mercury moves very quickly in its orbit. Maybe that's why it got such a name, because in Greek mythology Mercury is the messenger of the gods. There is practically no atmosphere here and the sky is always black, but the Sun shines very brightly. However, there are places at the poles where its rays never hit. This phenomenon can be explained by the tilt of the rotation axis. No water was found on the surface. This circumstance, as well as the abnormally high daytime temperature (as well as the low nighttime temperature) fully explain the fact of the absence of life on the planet.

Venus

If you study the planets of the solar system in order, then Venus comes second. People could observe it in the sky back in ancient times, but since it was shown only in the morning and evening, it was believed that these were 2 different objects. By the way, our Slavic ancestors called it Mertsana. It is the third brightest object in our solar system. Previously people They called it the morning and evening star, because it is best visible before sunrise and sunset. Venus and Earth are very similar in structure, composition, size and gravity. This planet moves very slowly around its axis, making a full revolution in 243.02 Earth days. Of course, conditions on Venus are very different from those on Earth. It is twice as close to the Sun, so it is very hot there. High temperature is also explained by the fact that thick clouds of sulfuric acid and an atmosphere of carbon dioxide create on the planet greenhouse effect. In addition, the pressure at the surface is 95 times greater than on Earth. Therefore, the first ship that visited Venus in the 70s of the 20th century stayed there for no more than an hour. Another peculiarity of the planet is that it rotates in the opposite direction compared to most planets. Astronomers still know nothing more about this celestial object.

Third planet from the Sun

The only place in the Solar System, and indeed in the entire Universe known to astronomers, where life exists is Earth. In the terrestrial group it has the largest size. What else are her

1. The highest gravity among the terrestrial planets.
2. Very strong magnetic field.
3. High density.
4. It is the only one among all the planets that has a hydrosphere, which contributed to the formation of life.
5. It has the largest satellite compared to its size, which stabilizes its tilt relative to the Sun and influences natural processes.

Planet Mars

This is one of the smallest planets in our Galaxy. If we consider the planets of the solar system in order, then Mars is the fourth from the Sun. Its atmosphere is very rarefied, and the pressure on the surface is almost 200 times less than on Earth. For the same reason, very strong temperature changes are observed. The planet Mars has been little studied, although it has long attracted the attention of people. According to scientists, this is the only celestial body on which life could exist. After all, in the past there was water on the surface of the planet. This conclusion can be drawn from the fact that there are large ice caps at the poles, and the surface is covered with many grooves, which could be dried up river beds. In addition, there are some minerals on Mars that can only be formed in the presence of water. Another feature of the fourth planet is the presence of two satellites. What makes them unusual is that Phobos gradually slows down its rotation and approaches the planet, while Deimos, on the contrary, moves away.

What is Jupiter famous for?

The fifth planet is the largest. The volume of Jupiter would fit 1300 Earths, and its mass is 317 times that of Earth. Like all gas giants, its structure is hydrogen-helium, reminiscent of the composition of stars. Jupiter is the most interesting planet, which has many characteristic features:

• it is the third brightest celestial body after the Moon and Venus;
• Jupiter has the strongest magnetic field of any planet;
• it completes a full revolution around its axis in just 10 Earth hours - faster than other planets;
• An interesting feature of Jupiter is the large red spot - this is how an atmospheric vortex rotating counterclockwise is visible from Earth;
• like all giant planets, it has rings, although not as bright as Saturn’s;
• this planet has the largest number of satellites. He has 63 of them. The most famous are Europa, where water was found, Ganymede - the largest satellite of the planet Jupiter, as well as Io and Calisto;
• Another feature of the planet is that in the shadow the surface temperature is higher than in places illuminated by the Sun.

Planet Saturn

It is the second largest gas giant, also named after the ancient god. It is composed of hydrogen and helium, but traces of methane, ammonia and water have been found on its surface. Scientists have found that Saturn is the rarest planet. Its density is less than that of water. This gas giant rotates very quickly - it makes one revolution in 10 Earth hours, as a result of which the planet is flattened from the sides. Huge speeds on Saturn and the wind - up to 2000 kilometers per hour. This is faster than the speed of sound. Saturn has another one distinctive feature- it holds 60 satellites in its field of attraction. The largest of them, Titan, is the second largest in the entire solar system. The uniqueness of this object lies in the fact that by examining its surface, scientists for the first time discovered a celestial body with conditions similar to those that existed on Earth about 4 billion years ago. But the most main feature Saturn is the presence of bright rings. They circle the planet around the equator and reflect more light than the planet itself. Four is the most amazing phenomenon in the Solar System. What's unusual is that the inner rings move faster than the outer rings.

- Uranus

So, we continue to consider the planets of the solar system in order. The seventh planet from the Sun is Uranus. It is the coldest of all - the temperature drops to -224 °C. In addition, scientists did not find metallic hydrogen in its composition, but found modified ice. Therefore, Uranus is classified as separate category ice giants. An amazing feature of this celestial body is that it rotates while lying on its side. The change of seasons on the planet is also unusual: winter reigns there for as many as 42 Earth years, and the Sun does not appear at all; summer also lasts 42 years, and the Sun does not set during this time. In spring and autumn, the star appears every 9 hours. Like all giant planets, Uranus has rings and many satellites. As many as 13 rings revolve around it, but they are not as bright as those of Saturn, and the planet contains only 27 satellites. If we compare Uranus with the Earth, then it is 4 times larger than it, 14 times heavier and is located at a distance from the Sun of 19 times the path to the star from our planet.

Neptune: the invisible planet

After Pluto was excluded from the number of planets, Neptune became the last from the Sun in the system. It is located 30 times further from the star than the Earth, and is not visible from our planet even with a telescope. Scientists discovered it, so to speak, by accident: observing the peculiarities of the movement of the planets closest to it and their satellites, they concluded that there must be another large celestial body beyond the orbit of Uranus. After discovery and research it became clear interesting features of this planet:

• due to the presence in the atmosphere large quantity methane, the color of the planet from space appears blue-green;
• Neptune's orbit is almost perfectly circular;
• the planet rotates very slowly - it makes one circle every 165 years;
• Neptune 4 times more than Earth and 17 times heavier, but the force of gravity is almost the same as on our planet;
• the largest of the 13 satellites of this giant is Triton. It is always turned to the planet with one side and slowly approaches it. Based on these signs, scientists suggested that it was captured by the gravity of Neptune.

Throughout the galaxy Milky Way- about one hundred billion planets. So far, scientists cannot study even some of them. But the number of planets in the solar system is known to almost all people on Earth. True, in the 21st century, interest in astronomy has faded a little, but even children know the names of the planets of the solar system.

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24.04.2015

Thanks to astronomical observations, we know that everything The planets of the solar system rotate around their own axis. And it is also known that everything planets have one or another angle of inclination of the rotation axis to the ecliptic plane. It is also known that during the year, each of the two hemispheres of any of the planets changes its distance to , but by the end of the year the position of the planets relative to the Sun turns out to be the same as a year ago (or, more precisely, almost the same). There are also facts that are unknown to astronomers, but which nevertheless exist. For example, there is a constant but smooth change in the angle of inclination of the axis of any planet. The angle increases. And, in addition to this, there is a constant and smooth increase in the distance between the planets and the Sun. Is there a connection between all of these phenomena?

The answer is yes, without a doubt. All these phenomena are due to the existence of planets as Fields of Attraction, so Repulsion Fields, the peculiarities of their location within the planets, as well as changes in their size. We are so accustomed to the knowledge that our rotates around its axis, and also to the fact that the northern and southern hemispheres of the planet alternately move away and then approach the Sun throughout the year. And with the rest of the planets everything is the same. But why do planets behave this way? What motivates them? Let's start with the fact that any of the planets can be compared to an apple skewered and roasted over a fire. The role of "fire" in in this case performed by the Sun, and the “skewer” is the axis of rotation of the planet. Of course, people often fry meat, but here we turn to the experience of vegetarians, because fruits often have a round shape, which brings them closer to the planets. If we roast an apple over a fire, we do not turn it around the source of the flame. Instead, we rotate the apple and also change the position of the skewer relative to the fire. The same thing happens with the planets. They rotate and change the position of the “skewer” relative to the Sun throughout the year, thus warming up their “sides”.

The reason why the planets rotate around their axes, and also during the year their poles periodically change their distance from the Sun, is approximately the same as why we turn an apple over a fire. The analogy with a spit was not chosen by chance here. We always keep the least cooked (least heated) area of ​​the apple over the fire. The planets also always tend to turn towards the Sun with their least heated side, the total Attraction Field of which is maximum compared to the other sides. However, the expression “striving to turn around” does not mean that this is what actually happens. The trouble is that any of the planets simultaneously has two sides at once, whose desire for the Sun is greatest. These are the poles of the planet. This means that from the very moment of the birth of the planet, both poles simultaneously sought to take such a position as to be closest to the Sun.

Yes, yes, when we talk about the attraction of a planet to the Sun, we should take into account that different areas of the planet are attracted to it in different ways, i.e. to varying degrees. At the smallest is the equator. At the greatest - the poles. Please note - there are two poles. Those. two regions at once tend to be at the same distance from the center of the Sun. The poles continue to balance throughout the planet's existence, constantly competing with each other for the right to occupy a position closer to the Sun. But even if one pole temporarily wins and turns out to be closer to the Sun compared to the other, this other one continues to “graze” it, trying to turn the planet in such a way that it itself is closer to the sun. This struggle between the two poles directly affects the behavior of the entire planet as a whole. It is difficult for the poles to get closer to the Sun. However, there is a factor that makes their task easier. This factor is existence angle of inclination of rotation to the ecliptic plane.

However, at the very beginning of the life of the planets, they did not have any axial tilt. The reason for the appearance of the tilt is the attraction of one of the poles of the planet by one of the poles of the Sun.

Let's consider how the tilt of the planets' axes appears?

When the material from which planets form is ejected from the Sun, the ejection does not necessarily occur in the plane of the Sun's equator. Even a slight deviation from the plane of the Sun's equator leads to the fact that the resulting planet is closer to one of the Sun's poles than to the other. To be more precise, only one of the poles of the resulting planet turns out to be closer to one of the poles of the Sun. For this reason, it is this pole of the planet that experiences greater attraction from the pole of the Sun, to which it happens to be closer.

As a result, one of the planet’s hemispheres immediately turned in the direction of the Sun. This is how the planet acquired an initial tilt of its rotation axis. The hemisphere that was closer to the Sun, accordingly, immediately began to receive more solar radiation. And because of this, this hemisphere began to warm up to a greater extent from the very beginning. Greater heating of one of the planet's hemispheres causes the total Gravitational Field of this hemisphere to decrease. Those. As the hemisphere that approached the Sun warmed up, its desire to approach the pole of the Sun began to decrease, the gravity of which caused the planet to tilt. And the more this hemisphere warmed up, the more the tendency of both poles of the planet became equal - each towards its nearest pole of the Sun. As a result, the warming hemisphere increasingly turned away from the Sun, and the cooler hemisphere began to move closer. But pay attention to how this change of poles happened (and is happening). Very peculiar.

Once a planet has formed from material ejected by the Sun and now orbits it, it immediately begins to be heated by solar radiation. This heating causes it to rotate around its own axis. Initially there was no tilt of the rotation axis. Because of this, the equatorial plane warms up to the greatest extent. Because of this, it is in the equatorial region that the non-vanishing Repulsion Field appears first and its magnitude is greatest from the very beginning. In the areas adjacent to the equator, a non-disappearing Repulsion Field also appears over time. The size of the area of ​​the areas in which there is a Repulsion Field is demonstrated by the angle of inclination of the axis.
But the Sun also has a constantly existing Repulsion Field. And, like the planets, in the region of the Sun’s equator the magnitude of its Repulsion Field is greatest. And since all the planets at the moment of ejection and formation ended up approximately in the region of the Sun’s equator, they thus revolved in the zone where the Sun’s Repulsion Field is greatest. It is precisely because of this, due to the fact that there will be a collision of the largest Repulsion Fields of the Sun and the planet, a change in the position of the hemispheres of the planet cannot occur vertically. Those. the lower hemisphere cannot simply go back and up, and the upper hemisphere cannot simply go forward and down.

During the process of changing hemispheres, the planet follows a “detour maneuver.” She makes a turn in such a way that her own equatorial Repulsion Field collides least with the equatorial Repulsion Field of the Sun. Those. the plane in which the equatorial Repulsion Field of the planet manifests itself turns out to be at an angle to the plane in which the equatorial Repulsion Field of the Sun manifests itself. This allows the planet to maintain its existing distance from the Sun. Otherwise, if the planes in which the Repulsion Fields of the planet and the Sun appear coincided, the planet would be sharply thrown away from the Sun.

This is how the planets change the position of their hemispheres relative to the Sun - sideways, sideways...

The time from the summer solstice to the winter solstice for any hemisphere represents a period of gradual heating of that hemisphere. Accordingly, the time from the winter solstice to the summer solstice is a period of gradual cooling. The very moment of the summer solstice corresponds to the lowest total temperature chemical elements of this hemisphere.
And the moment of the winter solstice corresponds to the highest total temperature of the chemical elements in the composition of a given hemisphere. Those. At the moments of the summer and winter solstices, the hemisphere that is coolest at that moment faces the Sun. Amazing, isn't it? After all, everything, as our everyday experience tells us, should be the other way around. After all, it is warm in summer and cold in winter. But in this case we are not talking about the temperature of the surface layers of the planet, but about the temperature of the entire thickness of the substance.

But the moments of the spring and autumn equinoxes precisely correspond to the time when the total temperatures of both hemispheres are equal. That is why at this time both hemispheres are at the same distance from the Sun.

And finally, I’ll say a few words about the role of heating planets by solar radiation. Let's do a little thought experiment to see what would happen if stars didn't emit elementary particles and thereby did not heat the planets around them. If the Sun had not heated the planets, they would all always be turned to the Sun with one side, just as the Moon, the Earth’s satellite, always faces the Earth with the same side. The absence of heating, firstly, would deprive the planets of the need to rotate around their own axis. Secondly, if there were no heating, there would be no consistent rotation of the planets towards the Sun by one or the other hemisphere during the year.

Thirdly, if there were no heating of the planets by the Sun, the axis of rotation of the planets would not be inclined to the ecliptic plane. Although with all this, the planets would continue to revolve around the Sun (around the star). And fourthly, the planets would not gradually increase their distance to .

Tatiana Danina

It took man many millennia to understand that the Earth is not the center of the Universe and is in constant motion.


Galileo Galilei's phrase “And yet it turns!” went down in history forever and became a kind of symbol of that era when scientists from different countries tried to refute the theory of the geocentric system of the world.

Although the rotation of the Earth was proven about five centuries ago, the exact reasons that motivate it to move are still unknown.

Why does the Earth spin around its axis?

In the Middle Ages, people believed that the Earth was motionless, and the Sun and other planets revolved around it. Only in the 16th century did astronomers manage to prove the opposite. Despite the fact that many associate this discovery with Galileo, in fact it belongs to another scientist - Nicolaus Copernicus.

It was he who wrote the treatise “On the Revolution of the Celestial Spheres” in 1543, where he put forward a theory about the movement of the Earth. For a long time this idea did not receive support from either his colleagues or the church, but in the end it had a huge impact on scientific revolution in Europe and became fundamental in further development astronomy.


After the theory about the rotation of the Earth was proven, scientists began to look for the causes of this phenomenon. Over the past centuries, many hypotheses have been put forward, but even today not a single astronomer can accurately answer this question.

Currently, there are three main versions that have the right to life - theories of inertial rotation, magnetic fields and the impact of solar radiation on the planet.

The theory of inertial rotation

Some scientists are inclined to believe that once upon a time (back at the time of its appearance and formation) the Earth spun, and now rotates by inertia. Formed from cosmic dust, she began to attract other bodies to her, which gave her additional impulse. This assumption also applies to other planets of the solar system.

The theory has many opponents, since it cannot explain why different times the speed of the Earth either increases or decreases. It is also unclear why some planets in the solar system rotate in the opposite direction, such as Venus.

Theory about magnetic fields

If you try to connect two magnets with an equally charged pole, they will begin to repel each other. The theory of magnetic fields suggests that the Earth's poles are also equally charged and seem to repel each other, which causes the planet to rotate.


Interestingly, scientists recently made a discovery that the Earth's magnetic field pushes its internal core from west to east and causes it to rotate faster than the rest of the planet.

Sun Exposure Hypothesis

The theory of solar radiation is considered to be the most probable. It is well known that it warms the surface shells of the Earth (air, seas, oceans), but the heating occurs unevenly, resulting in the formation of sea and air currents.

It is they, when interacting with the solid shell of the planet, that cause it to rotate. Continents act as a kind of turbines that determine the speed and direction of movement. If they are not monolithic enough, they begin to drift, which affects the increase or decrease in speed.

Why does the Earth move around the Sun?

The reason for the Earth's revolution around the Sun is called inertia. According to the theory about the formation of our star, about 4.57 billion years ago, a huge amount of dust appeared in space, which gradually turned into a disk, and then into the Sun.

The outer particles of this dust began to connect with each other, forming planets. Even then, by inertia, they began to rotate around the star and continue to move along the same trajectory today.


According to Newton's law, all cosmic bodies move in a straight line, that is, in fact, the planets of the solar system, including the Earth, should have long ago flown into outer space. But this doesn't happen.

The reason is that the Sun has a large mass and, accordingly, a huge gravitational force. The Earth, while moving, constantly tries to rush away from it in a straight line, but gravitational forces attract it back, so the planet is kept in orbit and revolves around the Sun.

From the school astronomy course, which is included in the geography lesson program, we all know about the existence of the solar system and its 8 planets. They “circle” around the Sun, but not everyone knows that there are celestial bodies with retrograde rotation. Which planet rotates in the opposite direction? In fact, there are several of them. These are Venus, Uranus and a recently discovered planet located on the far side of Neptune.

Retrograde rotation

The movement of each planet follows the same order, and solar wind, meteorites and asteroids, colliding with it, are forced to rotate around their axis. However, gravity plays the main role in the movement of celestial bodies. Each of them has its own inclination of the axis and orbit, the change of which affects its rotation. Planets move counterclockwise with an orbital inclination angle of -90° to 90°, and celestial bodies with an angle of 90° to 180° are classified as bodies with retrograde rotation.

Axis tilt

As for the axis tilt, retrograde given value is 90°-270°. For example, the axis tilt angle of Venus is 177.36°, which does not allow it to move counterclockwise, and the recently discovered space object Nika has an inclination angle of 110°. It should be noted that the effect of the mass of a celestial body on its rotation has not been fully studied.

Fixed Mercury

Along with retrograde ones, there is a planet in the solar system that practically does not rotate - this is Mercury, which has no satellites. Reverse rotation of planets is not such a rare phenomenon, but it is most often found outside the solar system. Today there is no generally accepted model of retrograde rotation, which makes it possible for young astronomers to make amazing discoveries.

Causes of retrograde rotation

There are several reasons why planets change their course of motion:

• collision with larger space objects
• change in orbital inclination angle
• change in axis tilt
• changes in gravitational field(intervention of asteroids, meteorites, space debris, etc.)

Also, the cause of retrograde rotation may be the orbit of another cosmic body. There is an opinion that the reason for the reverse movement of Venus could be solar tides, which slowed down its rotation.

Formation of planets

Almost every planet during its formation was subjected to many asteroid impacts, as a result of which its shape and orbital radius changed. An important role is also played by the fact that a group of planets and a large accumulation of space debris are formed nearby, resulting in a minimum distance between them, which, in turn, leads to a disruption of the gravitational field.