Which planet rotates counterclockwise? Solar system. Venus rotates backwards
Color image of Venus
We present to your attention the 10 most interesting facts about Venus, perhaps you already knew some of them, but perhaps others not.
Earth and Venus are similar in size and mass. In addition, they revolve around the Sun in very similar orbits. The size of Venus is only 650 km smaller than the size of Earth. The mass of Venus is 81.5% of the mass of the Earth.
But that's where the similarities end. The atmosphere of Venus consists of 96.5% carbon dioxide(CO2), the temperature on the planet is absolutely unsuitable for flora and fauna, because it reaches 475 °C. There is also very high pressure on Venus, which will crush you if you suddenly want to walk on the surface of this planet.
2. Venus is so bright that it can create shadows.
Astronomers measure the brightness of objects in the night sky by their magnitude. Only the Sun and Moon are brighter than Venus. Its brightness can range between -3.8 and -4.6 magnitudes, but what is clear is that it is always brighter than any of the brightest stars in the sky.
Venus can be so bright that it can actually cause shadows. Wait until it's a dark night when there's no moon in the sky and check it out for yourself.
3. The atmosphere of Venus is extremely hostile.
Although Venus is similar to Earth in size and mass, its atmosphere is unique in its own way. The mass of the atmosphere is 93 times greater than the mass of the Earth's atmosphere. If you suddenly found yourself on the surface of Venus, you would experience 92 times the pressure that you experience on Earth. This is the same as finding yourself almost a kilometer below the surface of the ocean.
And if pressure doesn't kill you, heat and toxic chemicals certainly will. Temperatures on Venus can reach 475° C. Thick clouds of sulfur dioxide on Venus create precipitation consisting of sulfuric acid. This is truly a hellish place...
4. Venus rotates in the opposite direction.
While a day on Earth takes only 24 hours, a day on Venus is equal to 243 of our Earth days. But what's even stranger is that Venus rotates in reverse side compared to the rest of the planets in the solar system. If you had a chance to look at the planets of the solar system from above, you would see that they all rotate counterclockwise. Except for Venus, which rotates clockwise.
5. Many missions have landed on the surface of Venus.
You probably thought that it would be impossible to land any apparatus on the surface of such a hellish world. And you are partially right. During the space race Soviet Union began a series of expeditions to the surface of Venus. But engineers underestimated how terrible the planet's atmosphere was.
The first spaceships were crushed when they entered the atmosphere of Venus. But finally automatic research space station Venera 8 was the first spacecraft to land on the surface of Venus and take and transmit images to Earth. Subsequent missions lasted longer and even returned the first color images of the surface of Venus.
6. People thought that Venus was covered with tropical forests.
Until the United States and the USSR began exploring Venus using spacecraft, no one really knew what was hiding under the planet’s thick clouds. Science fiction writers have described the planet's surface as a lush tropical jungle. The hellish temperatures and dense atmosphere surprised everyone.
7. Venus has no natural satellites.
Unlike, say, Earth, Venus has no natural satellites. Mars has two, and even Pluto has two. But not Venus.
8. Venus has phases.
Looking at Venus through a telescope, you can see that the planet is in one phase or another, like the Moon. When Venus is closest, it actually appears as a thin crescent moon. As Venus becomes fainter and more distant, you see a larger circle through the telescope.
9. There are several impact craters on the surface of Venus.
While the surfaces of Mercury, Mars and the Moon are littered with impact craters, the surface of Venus has relatively few craters. Experts believe that the surface of Venus is only five hundred million years old. Constant volcanism changes the surface, regularly covering any impact craters.
Venus is the second planet of the solar system. Its neighbors are Mercury and Earth. The planet was named after the Roman goddess of love and beauty - Venus. However, it soon turned out that the surface of the planet had nothing in common with beauty.
Knowledge about this celestial body was very scarce until the middle of the 20th century due to dense clouds hiding Venus from the view of telescopes. However, with the development of technical capabilities, humanity has learned many new and interesting facts about this amazing planet. Many of them raised a number of questions that are still unanswered.
Today we will discuss hypotheses that explain why Venus rotates counterclockwise and tell Interesting Facts about it, known planetology today.
What do we know about Venus?
In the 60s, scientists still had hope that the conditions on living organisms. These hopes and ideas were embodied in their works by science fiction writers who told about the planet as a tropical paradise.
However, after the spaceships that provided the first insight were sent to the planet, scientists came to disappointing conclusions.
Venus is not only uninhabitable, it has a very aggressive atmosphere that destroyed the first few spaceships sent into its orbit. But despite the fact that contact with them was lost, the researchers still managed to get an idea of chemical composition atmosphere of the planet and its surface.
Researchers were also interested in the question of why Venus rotates counterclockwise, just like Uranus.
Twin Planet
Today it is known that Venus and Earth are very similar in physical characteristics. Both of them belong to the terrestrial group of planets, like Mars and Mercury. These four planets have few or no satellites and have weak magnetic field and lack a ring system.
Venus and Earth have similar masses and are only slightly smaller than our Earth) and also rotate in similar orbits. However, this is where the similarities end. Otherwise, the planet is in no way similar to Earth.
The atmosphere on Venus is very aggressive and consists of 95% carbon dioxide. The temperature of the planet is absolutely unsuitable for life, as it reaches 475 °C. In addition, the planet has very high pressure (92 times higher than on Earth), which will crush a person if he suddenly decides to walk on its surface. Clouds of sulfur dioxide that create precipitation from sulfuric acid will also destroy all living things. The layer of these clouds reaches 20 km. Despite its poetic name, the planet is a hellish place.
What is the speed of rotation of Venus around its axis? As a result of research, one Venusian day is equal to 243 Earth days. The planet rotates at a speed of only 6.5 km/h (for comparison, the rotation speed of our Earth is 1670 km/h). Moreover, one Venusian year is 224 Earth days.
Why does Venus rotate counterclockwise?
This question has been worrying scientists for decades. However, so far no one has been able to answer it. There have been many hypotheses, but none of them have yet been confirmed. However, we will look at some of the most popular and interesting of them.
The fact is that if you look at the planets of the solar system from above, Venus rotates counterclockwise, while all other celestial bodies (except Uranus) rotate clockwise. These include not only planets, but also asteroids and comets.
When viewed from north pole, Uranus and Venus rotate clockwise, and all other celestial bodies rotate counterclockwise.
Reasons why Venus rotates counterclockwise
However, what was the reason for such a deviation from the norm? Why does Venus rotate counterclockwise? There are several popular hypotheses.
- Once upon a time, at the dawn of the formation of our solar system, there were no planets around the Sun. There was only one disk of gas and dust that rotated clockwise, which was eventually transmitted to other planets. A similar rotation was observed in Venus. However, the planet likely soon collided with a huge body that crashed into it against its rotation. Thus, the space object seemed to “launch” the movement of Venus in the opposite direction. Perhaps Mercury is to blame for this. This is one of the most interesting theories that explains several surprising facts. Mercury was probably once a satellite of Venus. However, later he collided with it tangentially, giving Venus part of his mass. He himself flew into a lower orbit around the Sun. That is why its orbit has a curved line, and Venus rotates in the opposite direction.
- Venus can be rotated by its atmosphere. The width of its layer reaches 20 km. At the same time, its mass is slightly less than that of the Earth. The density of Venus's atmosphere is very high and literally squeezes the planet. Perhaps it is the dense atmosphere that rotates the planet in a different direction, which explains why it rotates so slowly - only 6.5 km/hour.
- Other scientists, observing how Venus rotates on its axis, came to the conclusion that the planet is turned upside down. It continues to move in the same direction as the other planets, but due to its position it rotates in the opposite direction. Scientists believe that a similar phenomenon could be caused by the influence of the Sun, which caused strong gravitational tides in combination with friction between the mantle and the core of Venus itself.
Conclusion
Venus is a planet terrestrial group, unique in nature. The reason why it rotates in the opposite direction is still a mystery to mankind. Perhaps someday we will solve it. For now, we can only make assumptions and hypotheses.
We've been studying the solar system for hundreds of years, and you'd think we'd have answers to every frequently asked question about it. Why do the planets rotate, why are they in such orbits, why does the Moon not fall to the Earth... But we cannot boast of this. To see this, just look at our neighbor, Venus.
Scientists began to study it closely in the middle of the last century, and at first it seemed relatively dull and uninteresting. However, it soon became clear that this is the most natural hell with acid rain, which also rotates in the opposite direction! More than half a century has passed since then. We've learned a lot about Venus's climate, but we still haven't figured out why it spins differently than everyone else. Although there are many hypotheses on this matter.
In astronomy, rotation in the opposite direction is called retrograde. Since all solar system formed from one rotating gas cloud, all the planets move in orbits in the same direction - counterclockwise, if you look at this whole picture from above, from the north pole of the Earth. In addition, these celestial bodies also rotate around their own axis - also counterclockwise. But this does not apply to the two planets of our system - Venus and Uranus.
Uranus is actually lying on its side, most likely due to a couple of collisions with large objects. Venus rotates clockwise, and this is even more problematic to explain. One early hypothesis suggested that Venus collided with an asteroid, and the impact was so strong that the planet began to spin in the other direction. This theory was introduced to the public in 1965 by two astronomers processing radar data. Moreover, the definition of “thrown in” is in no way a derogation. As the scientists themselves stated, quote: “This possibility is dictated only by imagination. It is hardly possible to obtain evidence to support it.” Extremely convincing, isn't it? Be that as it may, this hypothesis does not stand up to the test of simple mathematics - it turns out that an object whose size is sufficient to reverse the rotation of Venus will simply destroy the planet. His kinetic energy will be 10,000 times more than what is needed to smash the planet into dust. In this regard, the hypothesis was sent to the distant shelves of scientific libraries.
It was replaced by several theories that had some kind of evidence base. One of the most popular, proposed in 1970, suggested that Venus originally rotated this way. It’s just that at some point in its history it turned upside down! This could have happened due to processes occurring inside Venus and in its atmosphere.
This planet, like the Earth, is multi-layered. There is also a core, mantle and crust. As the planet rotates, the core and mantle experience friction in the area of their contact. The atmosphere of Venus is very thick, and, thanks to the heat and gravity of the Sun, it is subject, like the rest of the planet, to the tidal influence of our star. According to the described hypothesis, friction between the crust and the mantle, coupled with atmospheric tidal fluctuations, created a torque, and Venus, losing stability, capsized. Simulations showed that this could only happen if Venus had an axis tilt of about 90 degrees from the moment of its formation. Later this number decreased somewhat. In any case, this is a highly unusual hypothesis. Just imagine - a tumbling planet! This is some kind of circus, not space.
In 1964, a hypothesis was put forward according to which Venus changed its rotation gradually - it slowed down, stopped, and began to spin in the other direction. This could be caused by several factors, including interaction with the Sun's magnetic field, atmospheric tides, or a combination of several forces. The atmosphere of Venus, according to this theory, spun in the other direction first. This created a force that first slowed down Venus and then spun it retrograde. As a bonus, this hypothesis also explains the long length of the day on the planet.
In the debate between the last two, there is no clear favorite yet. To understand which one to choose, we need to know much more about the dynamics of early Venus, in particular about its rotation speed and axis tilt. According to a 2001 paper published in the journal Nature, Venus would be more likely to capsize if it had a high initial rotation speed. But, if it was less than one revolution in 96 hours with a small axial tilt (less than 70 degrees), the second hypothesis looks more plausible. Unfortunately, it is quite difficult for scientists to look back four billion years. Therefore, until we invent a time machine or carry out computer simulations of unrealistically high quality today, progress in this matter is not expected.
It is clear that this is not Full description discussions regarding the rotation of Venus. For example, the very first of the hypotheses we described—the one that dates back to 1965—received an unexpected development not long ago. In 2008, it was suggested that our neighbor could have spun in the opposite direction at a time when she was still a small, unintelligent planetesimal. An object approximately the same size as Venus itself should have crashed into it. Instead of the destruction of Venus, there would be a merger of two celestial bodies into one full-fledged planet. The main difference from the original hypothesis here is that scientists may have evidence in favor of such a turn of events.
Based on what we know about the topography of Venus, there is very little water on it. Compared to Earth, of course. The moisture could disappear from there as a result of a catastrophic collision of cosmic bodies. That is, this hypothesis would also explain the dryness of Venus. Although there are also, no matter how ironic it may sound in this case, pitfalls. Water from the surface of the planet could simply evaporate under the rays of the hot Sun here. To clarify this issue, a mineralogical analysis of rocks from the surface of Venus is needed. If water is present in them, the hypothesis of an early collision will disappear. The problem is that such analyzes have not yet been carried out. Venus is extremely unfriendly to the robots we send to it. Destroys without any hesitation.
Be that as it may, building an interplanetary station with a Venus rover capable of working here is still easier than a time machine. Therefore, let's not lose hope. Perhaps humanity will receive an answer to the riddle about the “wrong” rotation of Venus in our lifetime.
From the course school astronomy, 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 sunny 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, for retrograde ones this 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 influence of mass celestial body 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 the gravitational field (interference 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 Venus's retrograde motion 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.