Our planet is in constant motion. Together with the Sun, it moves in space around the center of the Galaxy. And that, in turn, moves in the Universe. But the most important thing for all living things is the rotation of the Earth around the Sun and its own axis. Without this movement, conditions on the planet would be unsuitable for supporting life.
solar system
According to scientists' calculations, the Earth as a planet of the solar system was formed more than 4.5 billion years ago. During this time, the distance from the star practically did not change. The planet's speed and the sun's gravitational pull have balanced its orbit. It is not perfectly round, but stable. If the force of gravity of the luminary were stronger or the speed of the Earth decreased noticeably, then it would fall on the Sun. Otherwise, sooner or later, it would fly into space, ceasing to be a part of the system.
The distance from the Sun to the Earth makes it possible to maintain an optimal temperature on its surface. The atmosphere also plays an important role in this. As the Earth rotates around the Sun, the seasons change. Nature has adapted to such cycles. But if our planet were more distant, then the temperature on it would become negative. If she were closer, all the water would have evaporated, since the thermometer would have exceeded the boiling point.
The path of the planet around the star is called the orbit. The trajectory of this flight is not perfectly circular. It is elliptical. The maximum difference is 5 million km. The closest point of the orbit to the Sun is at a distance of 147 km. It is called perihelion. Her land passes in January. In July, the planet is at the maximum distance from the star. The longest distance is 152 million km. This point is called the aphelion.
The rotation of the Earth around its axis and the Sun provides a corresponding change in daily regimes and annual periods.
For a person, the movement of the planet around the center of the system is imperceptible. This is due to the fact that the mass of the Earth is enormous. Nevertheless, every second we fly about 30 km in space. It seems unrealistic, but these are the calculations. On average, it is believed that the Earth is located from the Sun at a distance of about 150 million km. It makes one complete revolution around the star in 365 days. The distance covered in a year is almost a billion kilometers.
The exact distance that our planet travels in a year, moving around the star, is 942 million km. Together with her we move in space in an elliptical orbit at a speed of 107,000 km / h. The direction of rotation is from west to east, that is, counterclockwise.
The planet does not complete its full revolution in exactly 365 days, as is commonly believed. In this case, about six more hours pass. But for the convenience of chronology, this time is taken into account in total for 4 years. As a result, one additional day "runs up", it is added in February. This year is considered a leap year.
The speed of rotation of the Earth around the Sun is not constant. It has deviations from the mean. This is due to the elliptical orbit. The difference between the values is most pronounced at the points of perihelion and aphelion and is 1 km / s. These changes are imperceptible, since we and all objects around us move in the coordinate system in the same way.
Change of seasons
The rotation of the Earth around the Sun and the tilt of the planet's axis make it possible to change the seasons. It is less noticeable at the equator. But closer to the poles, the annual cyclicality is more pronounced. The northern and southern hemispheres of the planet are heated unevenly by the energy of the Sun.
Moving around the star, they pass four conventional points of the orbit. At the same time, alternately twice during a six-month cycle, they turn out to be farther or closer to it (in December and June - the days of the solstices). Accordingly, in a place where the planet's surface warms up better, the ambient temperature there is higher. The period in such a territory is usually called summer. In the other hemisphere at this time it is noticeably colder - there is winter.
After three months of such movement with a frequency of six months, the planetary axis is positioned in such a way that both hemispheres are in the same conditions for heating. At this time (in March and September - the days of the equinox) the temperature regimes are approximately equal. Then, depending on the hemisphere, fall and spring come.
Earth axis
Our planet is a spinning ball. Its movement is carried out around a conventional axis and occurs according to the principle of a top. Leaning with the base on a plane in an untwisted state, it will maintain balance. When the rotation speed decreases, the top falls.
The ground does not have an emphasis. The forces of attraction of the Sun, Moon and other objects of the system and the Universe act on the planet. Nevertheless, it maintains a constant position in space. Its rotation speed, obtained during the formation of the nucleus, is sufficient to maintain relative equilibrium.
The earth's axis passes through the planet's ball not perpendicularly. It is tilted at an angle of 66 ° 33 '. The rotation of the Earth around its axis and the Sun makes it possible to change the seasons of the year. The planet would "tumble" in space if it did not have a strict orientation. There would be no question of any constancy of environmental conditions and life processes on its surface.
Axial rotation of the Earth
The rotation of the Earth around the Sun (one revolution) occurs during the year. During the day, day and night change on it. If you look at the North Pole of the Earth from space, you can see how it rotates counterclockwise. It makes a complete revolution in about 24 hours. This period is called days.
The speed of rotation determines how quickly day and night change. In one hour, the planet turns about 15 degrees. The speed of rotation at different points on its surface is different. This is due to the fact that it has a spherical shape. At the equator, the linear speed is 1669 km / h, or 464 m / s. Closer to the poles, this indicator decreases. At the thirtieth latitude, the linear speed will already be 1445 km / h (400 m / s).
Due to axial rotation, the planet has a shape somewhat compressed from the poles. Also, this movement "forces" moving objects (including air and water currents) to deviate from the original direction (Coriolis force). Another important consequence of this rotation is the ebb and flow.
the change of night and day
A spherical object is only half illuminated by a single source of light at a given moment. With regard to our planet, in one of its parts at this moment there will be a day. The unlit part will be hidden from the Sun - there is night. Axial rotation makes it possible to alternate between these periods.
In addition to the light regime, the conditions for heating the planet's surface by the energy of the luminary change. This cyclicality is important. The rate of change of light and thermal modes is carried out relatively quickly. In 24 hours, the surface does not have time to either heat up excessively or cool below the optimal indicator.
The rotation of the Earth around the Sun and its axis at a relatively constant speed is of decisive importance for the animal world. Without the constancy of its orbit, the planet would not have kept itself in the optimal heating zone. Without axial rotation, day and night would last for six months. Neither one nor the other would contribute to the emergence and preservation of life.
Irregularity of rotation
Throughout its history, mankind has become accustomed to the fact that the change of day and night occurs constantly. This served as a kind of standard of time and a symbol of the uniformity of life processes. The period of rotation of the Earth around the Sun, to a certain extent, is influenced by the ellipticity of the orbit and other planets of the system.
Another feature is the change in the length of the day. The axial rotation of the Earth is uneven. There are several main reasons. Seasonal fluctuations related to atmospheric dynamics and rainfall distribution are important. In addition, the tidal wave directed against the direction of the planet's movement constantly slows it down. This indicator is negligible (for 40 thousand years for 1 second). But over 1 billion years under the influence of this, the length of the day increased by 7 hours (from 17 to 24).
The consequences of the rotation of the Earth around the Sun and its axis are being studied. These studies are of great practical and scientific importance. They are used not only to accurately determine stellar coordinates, but also to identify patterns that can affect the processes of human life and natural phenomena in hydrometeorology and other fields.
The earth rotates on an inclined axis from west to east. Half of the globe is illuminated by the sun, it is day there at this time, the other half is in the shade, there is night. Due to the rotation of the Earth, there is a change of day and night. The Earth makes one revolution around its axis in 24 hours - a day.
Due to rotation, there is a deviation of moving streams (rivers, winds) in the northern hemisphere - to the right, and in the southern - to the left.
The rotation of the earth around the sun
Around the sun, the Earth revolves in a circular orbit, a full revolution is completed in 1 year. The Earth's axis is not vertical, it is tilted at an angle of 66.5 ° to the orbit, this angle remains constant throughout the rotation. The main consequence of this rotation is the change of seasons.
Consider the rotation of the Earth around the Sun.
- December 22- winter solstice. Closest to the sun (the sun is at its zenith) at this moment is the southern tropic - therefore, in the southern hemisphere it is summer, in the northern hemisphere - winter. The nights in the southern hemisphere are short, in the southern polar circle on December 22, a day lasts 24 hours, night does not come. In the Northern Hemisphere, on the contrary, in the Arctic Circle, the night lasts 24 hours.
- June, 22- the day of the summer solstice. Closest to the sun is the northern tropic, summer in the northern hemisphere, winter in the southern. In the southern polar circle, night lasts 24 hours, and in the northern polar circle, night does not occur at all.
- March 21, September 23- the days of the vernal and autumnal equinoxes The equator is closest to the sun; day is equal to night in both hemispheres.
For a long time, people have wondered why night gives way to day, winter in spring, and summer in autumn. Later, when the first questions were answered, scientists began to consider the Earth as an object in more detail, trying to find out at what speed the Earth rotates around the Sun and around its axis.
In contact with
Earth movement
All celestial bodies are in motion, the Earth is no exception. Moreover, it simultaneously has axial movement and movement around the Sun.
To visualize the movement of the Earth, just look at the top, which simultaneously rotates around its axis and quickly moves along the floor. If this movement did not exist, the Earth would not be habitable. So, our planet without rotation around its axis would be constantly turned to the Sun by one of its sides, on which the air temperature would reach +100 degrees, and all the water available in this area would turn into steam. On the other side, the temperature would be constantly minus and the entire surface of this part would be covered with ice.
Rotation orbit
Rotation around the Sun follows a certain trajectory - an orbit, which was established due to the attraction of the Sun and the speed of movement of our planet. If the attraction were several times stronger or the speed was much lower, then the Earth fell into the Sun. And if the attraction disappeared or greatly decreased, then the planet, driven by its centrifugal force, flew tangentially into space. It would be like rotating an object tied to a rope over your head and then releasing it abruptly.
The trajectory of the Earth's motion has the shape of an ellipse, not an ideal circle, and the distance to the star is not the same throughout the year. In January, the planet approaches the point closest to the star - it is called perihelion - and is 147 million km away from the star. And in July, the Earth moves away from the sun by 152 million km, approaching a point called aphelion. The average distance is taken as 150 million km.
The Earth moves in its orbit from west to east, which corresponds to a counterclockwise direction.
For 1 revolution around the center of the solar system, the Earth needs 365 days 5 hours 48 minutes 46 seconds (1 astronomical year). But for convenience, it is customary to count 365 days for a calendar year, and the remaining time "accumulates" and adds one day to each leap year.
The orbital distance is 942 million km. Based on calculations, the speed of the Earth is 30 km per second or 107,000 km / h. For people, it remains invisible, since all people and objects move in the same way in the coordinate system. And yet it is very large. For example, the fastest speed of a racing car is 300 km / h, which is 365 times slower than the speed of the Earth in its orbit.
However, the value of 30 km / s is not constant due to the fact that the orbit is an ellipse. The speed of our planet during the entire journey fluctuates somewhat. The greatest difference is achieved when passing the points of perihelion and aphelion and is 1 km / s. That is, the assumed speed of 30 km / s is average.
Axial rotation
The earth's axis is a conditional line that can be drawn from the north to the south pole. It passes at an angle of 66 ° 33 relative to the plane of our planet. One revolution occurs in 23 hours 56 minutes and 4 seconds, this time is indicated by sidereal days.
The main result of axial rotation is the change of day and night on the planet. In addition, due to this movement:
- The earth is shaped with flattened poles;
- bodies (river flow, wind) moving in a horizontal plane are slightly displaced (in the Southern Hemisphere - to the left, in the Northern - to the right).
The speed of axial movement in different sections is significantly different. The highest at the equator is 465 m / s or 1674 km / h, it is called linear. Such speed, for example, in the capital of Ecuador. In areas north or south of the equator, the rotation rate decreases. For example, in Moscow it is almost 2 times lower. These speeds are called angular, their exponent becomes smaller as they approach the poles. At the poles themselves, the speed is zero, that is, the poles are the only parts of the planet that are motionless about the axis.
It is the location of the axis at a certain angle that determines the change of the seasons. Being in exactly this position, different regions of the planet receive different amounts of heat at different times. If our planet were located strictly vertically relative to the Sun, then there would be no seasons at all, since the northern latitudes illuminated by the luminary in the daytime received as much heat and light as the southern latitudes.
Axial rotation is influenced by the following factors:
- seasonal changes (precipitation, atmospheric movement);
- tidal waves against the direction of axial movement.
These factors slow down the planet, as a result of which its speed decreases. The indicator of this decrease is very small, only 1 second in 40,000 years, however, in 1 billion years, the days have lengthened from 17 to 24 hours.
The movement of the Earth continues to be studied to this day.... This data helps to compile more accurate stellar maps, as well as to determine the connection of this movement with natural processes on our planet.
For billions of years, day after day, the Earth revolves on its axis. This makes sunrises and sunsets a commonplace for life on our planet. The Earth has been doing this since it formed 4.6 billion years ago. And it will continue to do so until it ceases to exist. This is likely to happen when the Sun turns into a red giant and swallows our planet. But why Earth?
Why does the Earth rotate?
The earth was formed from a disk of gas and dust that revolved around the newborn Sun. Thanks to this spatial disk, dust and rock particles were combined to form the Earth. As the Earth grew, the space rocks continued to collide with the planet. And they had an impact on it, which made our planet rotate. And since all the debris in the early solar system revolved around the sun in roughly the same direction, the collisions that caused the Earth (and most of the rest of the solar system's bodies) to spin spun it in that same direction.
Gas and dust disk
A reasonable question arises - why did the gas-dust disk itself rotate? The sun and solar system were formed at the moment when the cloud of dust and gas began to thicken under its own weight. Most of the gas came together to become the Sun, and the remaining material created the planetary disk surrounding it. Before it took shape, gas molecules and dust particles moved within its boundaries evenly in all directions. But at some point, randomly, some gas and dust molecules put their energy in one direction. This established the direction of rotation of the disc. When the gas cloud began to compress, its rotation accelerated. The same process occurs when the skaters begin to spin faster if they press their hands to the body.
In space, there are not many factors capable of planetary rotation. Therefore, as soon as they begin to rotate, this process does not stop. The rotating young solar system has a large angular momentum. This characteristic describes the tendency of an object to continue rotating. It can be assumed that all exoplanets, too, probably begin to rotate in the same direction around their stars when their planetary system forms.
And we are spinning the other way around!
Interestingly, in the solar system, some planets have a direction of rotation opposite to the movement around the sun. Venus rotates in the opposite direction to Earth. And the axis of rotation of Uranus is tilted 90 degrees. Scientists do not fully understand the processes that caused these planets to obtain such directions of rotation. But they have some guesses. Venus may have received such a rotation as a result of a collision with another cosmic body at an early stage of its formation. Or perhaps Venus began to rotate just like other planets. But over time, the sun's gravity began to slow down its rotation due to its dense clouds. Which, combined with the friction between the planet's core and its mantle, caused the planet to rotate the other way.
In the case of Uranus, scientists theorized that there was a collision of the planet with a huge rocky debris. Or perhaps with several different objects that changed the axis of its rotation.
Despite such anomalies, it is clear that all objects in space rotate in one direction or another.
Everything revolves
Asteroids rotate. The stars are turning. According to NASA, galaxies rotate too. The solar system takes 230 million years to complete one revolution around the center of the Milky Way. Some of the fastest rotating objects in the universe are dense, circular objects called pulsars. They are the remnants of massive stars. Some pulsars, which are the size of a city, can orbit around their axis hundreds of times per second. The fastest and most famous of them, discovered in 2006 and dubbed Terzan 5ad, rotates 716 times per second.
Black holes can do this even faster. It is assumed that one of them, named GRS 1915 + 105, can rotate at a speed of 920 to 1150 times per second.
However, the laws of physics are unforgiving. All rotations eventually slow down. When, it rotated on its axis at a rate of one revolution every four days. Today our star takes about 25 days to complete one revolution. Scientists believe the reason for this is because the sun's magnetic field interacts with the solar wind. This is what slows down its rotation.
The rotation of the Earth is also slowing down. The gravity of the moon acts on the earth in such a way that it slowly slows down its rotation. Scientists have calculated that the Earth's rotation has slowed by about 6 hours in total over the past 2,740 years. This is only 1.78 milliseconds over a century.
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When I was little I learned that The earth is turning... My grandfather once told me about a sundial and what is its principle. It's so customary to watch the sunrise and sunset Suns, but what if The earth will stop?
Which way does the earth rotate
It all depends on how you look at it. Relatively South Pole, the globe will rotate in the direction clockwise, and quite the opposite on North Pole... It is logical that the rotation occurs in the direction of the east - after all, the Sun appears from the east and disappears in the west. Scientists have found that the planet is gradually slows down by thousandths of a second per year. Most of the planets in our system have the same direction of rotation, the only exceptions are Uranus and Venus... When looking at the Earth from space, two types of motion can be noted: around its axis, and around the star - the Sun.
Few did not notice maelstrom water in the bathroom. This phenomenon, despite its routine, is a rather big mystery for the scientific world. Indeed, in Northern hemisphere the vortex is directed counterclock-wise, but in the opposite - the opposite is true. Most scholars regard this as a manifestation of power. Coriolis(inertia caused by rotation Of the earth). Some other manifestations of this power can be cited in favor of this theory:
- v northern hemisphere central winds cyclone blow counterclockwise, in the south - vice versa;
- the left rail of the railroad is most worn out in Southern hemisphere, while in the opposite - right;
- by rivers in Northern hemisphere pronounced right steep bank, in the South - on the contrary.
What if she stops
It is interesting to assume what will happen if our planet stop spinning... For the average person, this would be equivalent to driving cars at a speed of 2000 km / h, followed by hard braking... I don't think it's worth explaining the consequences of such an event, but it won't be the worst. If you are at this moment on equator, the human body will continue to "fly" at a speed of almost 500 meters per second, but those who are lucky enough to be closer to poles, will be able to survive, but not for long. The wind will become so strong that the strength of its action will be comparable to the strength explosion of a nuclear bomb, and the friction of the winds will cause fires all over the planet.
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