"Our planet rotates" - such an approval has long become apparent. Moreover, the rotation is difficult, probably even more complicated than you can imagine and until the very end of the person who has not been studied, because it is not yet known until the borders of the universe, and no one can say - the whole of our turns around peace. However, any rotation, like any movement, is relative, and it seems to us from the ground that it is not us, and the whole world revolves around us, therefore it took so many centuries that a person realize the rotation of his own planet. And what now seems obvious, in fact it was very, very difficult: to look at your world from the outside, especially when it seems that he is the center of the Universe. Let us try to figure out how our planet rotates, and what consequences of this arise.

Rotation around its axis

The Earth revolves around his axis and makes a complete turn in 24 hours. On our side - on Earth - we are watching the movement of the sky, the sun, planets and stars. The sky rotates from the east to the west, so the sun and planets are torn in the east and come in the West. The main celestial body for us, of course, is the sun. The rotation of the Earth around its axis leads to the fact that the sun rises above the horizon every day and falls for him every night. Actually, this is the reason that day and night replace each other. Muana has great importance for our planet. The moon shines lightly reflected by the sun, so that it can not depend on the change of day and night, however, the moon is a very massive heavenly object, so it can attract a liquid shell of the earth -, slightly deforming it. According to cosmic standards, attraction is insignificant, but on our - quite tangible. Twice a day we watch the tide and twice a day - a tump. Tides are observed on the part of the planet over which the moon is located, as well as on the opposite of it. Salves are shifted relative to the tides of 90 °. The moon makes a full turn around the earth for a month (hence the name of the incomplete moon in the sky), during the same time and makes a full turn around his axis, so we always see only one side of the moon. How to know if the moon rolled in our sky, perhaps people would guesses themselves about the rotation of their planet much earlier.
Conclusions: the rotation of the Earth around its axis leads to a change of day and night, the occurrence of tides and sings.

Rotation around the Sun.

Only in the 17th century, the heliocentric model of the world (the land and planets rotate around the sun) finally pushed out a geocentric model (the sun and the planet rotate around the Earth). The development of astronomy and observation of the planets made it impossible to approve the rotation of the world around the Earth. Now it is obvious to all that our planet makes turn around the sun approximately for 365.25 days. Unfortunately, it is not too convenient, and it is impossible to round this date, otherwise the error will accumulate in 4 years. By the way, this feature created a lot of problems with ancient peoples, because the preparation of the calendar because of the uneven numbers of days a year turned into confusion. It was touched by even ancient Rome, she walked such a proverb, which in the free interpretation meant that the Romans always commit great victories, but they definitely do not know what day it happened. The required reform of the calendar spent in 45 BC. Julius Caesar. It is in his honor that the seventh month of the year we still call "July". In the Julian calendar, every 4 year leap, that is, it is 366 days - added on February 29. However, this system was not quite accurate, since over time and the error began to accumulate in it. The year actually has a smaller duration for 11 minutes, which becomes essential for centuries. Approximately 128 years old, the Julian calendar accumulates an error in 1 day. Because of this, I had to introduce a new one - the Grigorian calendar (I was introduced by the Roman Pope Gregory XIII). We still use this calendar. In it, not all the years that are divided into 4 are considered leaps. Years that are more than 100 are visible only if they are divided into 400. But even this calendar is not perfect, it will accumulate a mistake in 1 day in 10,000 years. True, we still suite such an error. In other words, this problem is purely technically solved in the commissioning every 10 thousand years. February 30, we really do not threaten.
So, the Earth rotates around the Sun in one year, while it takes place at the time of year. The reason for this in the slope of the earth axis. The axis of rotation of our planet (and we see on the globe) tilted at an angle of 23.5 °. At the same time, she always "looks" at one point of heaven, next to which the polar star is located, creating the impression that the heavenly sphere revolves around this point. The slope of the earth's axis leads to the fact that six months, the land is tilted by the Northern Hemispheres to the Sun, and half a year - they are turned off the northern and facing southern. This leads to the fact that the height of the sun over the horizon from the month changes - in winter it rises low, we get a little heat, and it becomes cold. But on the opposite hemisphere at this moment, summer - it is crushed to the sun, six months old comes from us. The sun rises above the horizon more and warms our half of the earth, though, on the other side, the planet comes in winter. (See Figure; Source: http://www.rgo.ru/2011/01/kogda-prixodit-osen/)
I would like to note that we consider the slope of the earth axis constant, and by the standards of human life it is so, although not quite. The fact is that the North Pole of the World in Heaven (where the Polar Star is there) is slowly shifting. This phenomenon is called precession poles. The same process is observed at the twisted wag, which we begin to see well when the top starts to stop. Despite the rapid rotation, his handle begins to describe the circles, slowly changing the direction of the tilt of its axis. Of course, the Earth is not a top and strict parallel, it is impossible to hold, but the process goes similar, so after a few thousand years the polar star will no longer be in the "Pole of the World". However, during the life of a person will not be able to observe such processes. Equally as a change in the inclination of the earth's axis. Obviously, for 4.5 billion years of existence, the slope of our planet changed that he had serious consequences for the entire planet, but the change in the axis tilt can occur no faster than 1 ° over hundreds of thousands of years! Some pseudo-contaminated films tell us about a possible almost instantaneous shift of geographic poles, but according to the laws of nature, it cannot physically happen.
Conclusion: the rotation of the Earth around the Sun leads to a change in the seasons, due to the constant slope of the earth axis 23.5 °

Rotation around the center of the Galaxy

The earth and the whole solar system are in the galaxy, which we call the Milky Way. It was such a name due to the fact that what is our galaxy in the clean sky outside the city in a moonless night looks like a light elongated strip. Ancient, she resembled milk spilled across the sky, which is actually millions of stars of our galaxy. The galaxy actually has a spiral shape and should be similar to our nearest neighbor - the Galaxy Nebula Andromeda (in the photo.). Unfortunately, we can not yet look at your own galaxy from the side, but modern calculations and observations show that our system is rather closer to the edge of the Milky Way in one of its sleeves. The spiral galaxy sleeves slowly rotate around her center, together with them and we. Full turn around the center of the Galaxy Earth and the entire solar system is made for 225-250 million years. Unfortunately, it is still known about the consequences of this rotation, since the conscious life of humanity on Earth is measured by thousands of years, and serious observations are undergoing only a few centuries, however, the processes occurring in the galaxy also should somehow affect our planet's life, But this is also to find out.

The land is constantly in motion, rotating around the Sun and around its own axis. This movement and permanent tilt of the land axis (23.5 °) defines many effects that we observe as normal phenomena: night and day (due to the rotation of the earth around your axis), the change of seasons (due to the tilt of the land axis), and Different climate in various fields. Globes can be rotated and their axis has a slope as well as the Earth axis (23.5 °), so using the globe you can trace the movement of the earth around your axis quite accurately, and you can trace the movement of the earth around the sun with the help of the Sun system.

Rotation of the Earth around its axis

The Earth rotates around its own axis from the West to the East (counterclockwise, if you look from the North Pole). Earth is required 23 hours, 56 minutes, and 4.09 seconds to finish one full turn around your own axis. Day and night are due to the rotation of the Earth. The angular speed of rotation of the Earth around its axis or an angle to which any point turns on the surface of the Earth, the same. It is 15 degrees in one hour. But the linear speed of rotation anywhere in the equator is approximately 1,669 kilometers per hour (464 m / s), decreasing to zero on the poles. For example, rotation speed on a latitude of 30 ° - 1445 km / h (400 m / s).
We do not notice the rotation of the Earth for the simple reason that in parallel and at the same time with us are moving at the same speed all items around us and there are no "relative" movements of objects around us. If, for example, the ship will go evenly, without accelerating and braking around the sea in calm weather without excitement on the surface of the water, we will not feel at all how such a ship moves, if we are in a cabin without an illuminator, since all items inside the cabins will be Move in parallel with us and ship.

Movement of the Earth around the Sun

While the Earth rotates around his own axis, it turns around the Sun from the West to the East counterclockwise, if you look at the North Pole. Earth requires one starry year (about 365,2564 days) to finish one full turn around the sun. The path of the movement of the Earth around the Sun is called the Earth orbit And this orbit is not perfectly round. The average distance from the ground to the Sun is approximately 150 million kilometers, and this distance varies up to 5 million kilometers, forming small orbits (ellipse). The nearest point of the Earth's orbit, is called - perigelius. The land passes this point in early January. The most remote from the sun is the land orbit of the Earth, called - Aflia. The land passes this point in early July.
Since our land moves around the Sun along the elliptical trajectory, the orbit speed changes. In July, the speed is minimal (29.27 km / s) and after the passage of Afhelia (the upper red point on the animation) it begins to accelerate, and in January the speed is maximum (30.27 km / s) and begins to slow down after passing the perihelia (lower red dot ).
At that time, the Earth makes one turn around the Sun, it overcomes the distance equal to 942 million kilometers in 365 days, 6 hours, 9 minutes and 9.5 seconds, that is, we rush together with the earth around the Sun with an average speed of 30 km per second (or 107 460 km per hour), and at the same time, the Earth rotates around his own axis 24 hours once (for a year 365 times).
In fact, if we consider the movement of the Earth more scrupulously, it is much more complicated, as various factors affect the Earth: the rotation of the moon around the earth, the attraction of other planets and stars.

Even in ancient times, watching the starry sky, people noticed that in the afternoon the sun, and on the night sky - almost all the stars - from time to time they repeat their way. It brought to the idea that there are two reasons for this phenomenon. Or happens on the background of a fixed starry sky, or the sky rotates around the Earth. Claudius Ptolemy, an outstanding ancient Greek astronomer, a scientist and geographer, as if he decided to make this question, convincing everyone that the sun was rotating and the sky around the fixed land. Despite the fact that he could not explain many of many with this.

The heliocentric system based on another version won their recognition in long and dramatic struggle. Died at the fire of Jordan Bruno, the elderly Galilee recognized the "right-way" of the Inquisition, but "... after all, she spins!"

Today, the rotation of the Earth around the Sun is considered quite proven. In particular, the movement of our planet in the near-bearer orbit is proved by the aberration of the star light and the parallact displacement with a frequency of one year. Today it has been established that the direction of rotation of the Earth, more precisely, its barycenter, in orbit coincides with the direction of its rotation around the axis, that is, it comes from west to the east.

There are many facts telling that the Earth moves in space in a very difficult orbit. The rotation of the Earth around the Sun is accompanied by its movement around the axis, precession, nouting oscillations and rapid flight along with the sun on a spiral within the galaxy, which also does not stand still.

Rotation of the Earth around the Sun, like other planets, passes through an elliptical orbit. Therefore, once a year, January 3, the Earth is as close as possible from the Sun and once, July 5, removes from him to the largest distance. The difference between the periecelium (147 million km) and Appliances (152 million km), compared with the distance from the Sun to the Earth, was very small.

Moving along the near-bearer orbit, our planet makes 30 km per second, and the turnover of the Earth around the Sun is completed for 365 d. 6 h. This is the so-called Siderician, or Star, year. For practical amenities, it is considered to be 365 days a year. "Extension" 6 hours in 4 years in the amount give 24 hours, that is, one more day. These (who came, superfluous) and add to February once every 4 years. Therefore, in our calendar 3 years include 365 days, and the leap - the fourth year, contains 366 days.

The axis of its own rotation of the Earth is under the inclination to the orbital plane in 66.5 °. In this regard, during the year, the rays of the sun fall for each point of the earth's surface under

corners. Thus, at different times of the year, the point on different is obtained at the same time the unequal amount of light and heat. Because of this, in moderate latitudes of the seasons, they have a sharply pronounced character. At the same time, throughout the year, the sun's rays at the equator fall to the ground at the same angle, therefore, and the seasons there are slightly different from each other.

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Planet Earth

The main movements of the earth in space

© Vladimir Kalanov,
website "Knowledge is power".

Our planet rotates around its own axis from the West to the East, that is, counterclockwise (if you look from the North Pole). The axis is a conditional straight line crossing the globe in the area of \u200b\u200bthe Northern and South Poles, that is, the poles have a fixed position and "do not participate" in the rotational motion, while all other location points on the earth's surface rotate, and the linear speed of rotation on The surface of the globe depends on the position in relation to the equator - the closer to the equator, the linear speed of rotation is higher (we will explain that the angular speed of rotation of any ball is the same at different points and is measured in rad / s, we discuss the speed of moving the object located on The surface of the earth and it is higher than the more object removed from the rotation axis).

For example, on the average latitudes of Italy, the speed of rotation is approximately 1200 km / h, at the equator it is maximum and amounts to 1670 km / h, whereas on the poles it is zero. The consequences of the rotation of the Earth around their axis are the change of day and night and the visible movement of the heavenly sphere.

Indeed, it seems that the stars and other celestial bodies of the night sky are moving in the opposite of our direction with the planet direction (that is, from the east to the west). It seems that the stars are around the polar star, which is located on the imaginary line - the continuation of the earth's axis in the northern direction. The movement of the stars is not proof that the Earth revolves around its axis, because this movement could be a consequence of the rotation of the heavenly sphere, if we assume that the planet occupies a fixed, immobile position in space, as thought before.

Day. What is Sideric and Sunny Day?

A day is a segment of time for which the Earth makes a complete turn around the own axis. There are two definitions of the concept of "day". "Sunny day" is a lapse of the rotation time of the Earth, in which the sun is taken for the starting point. Another concept is "Sideric Day" (from Lat. sidus. - Genitive sideris - Star, heavenly shovel) - implies another starting point - "fixed" star, the distance to which is directed toward infinity, in connection with which we admit that its rays are mutually acceptable. The duration of two types of day differs from each other. Sideric Days make up 23 h 56 min 4 s, the duration of the sunny day is slightly longer and is equal to 24 hours. The difference is related to the fact that the Earth, rotating around its own axis, performs orbital rotation around the Sun. To deal with this is easier with the drawing.

Sun and Sideric Days. Explanation.

Consider two positions (see Fig.), Which land takes, making promotion on its orbit around the Sun, " BUT"- the place of the observer on the earth's surface. 1 - The situation that occupies the Earth (at the beginning of the countdown of the day) or from the Sun, or from any star that we define as a reference point. 2 - The position of our planet after turning around the turn around the own axis relative to this star: the light of this star, and it is on a great distance, it will come to us in parallel 1 . When the earth will occupy 2 , you can talk about "Sideric Days", because The Earth made a complete turn around his axis relative to the long star, but not yet relative to the sun. The direction of surveillance for the Sun has changed somewhat due to the appeal of the Earth. In order for the Earth to make a complete turn around the own axis relative to the sun ("Sunny Day"), you need to wait for it to "trust" about 1 ° (equivalent to the daily movement of the Earth at an angle - it passes 360 ° 55 days), it is It will take just about four minutes.

In principle, the duration of the sunny day (although it is accepted in 24 hours) - the value is non-permanent. This is due to the fact that the movement of the Earth in orbit actually occurs at variable speed. When the Earth is closer to the Sun, the speed of her movement in orbit is higher, as it removes the speed drops down. In this regard, this concept is introduced as "Average sunny day", It is their duration twenty-four hours.

In addition, it has now been reliably established that the period of rotation of the Earth increases under the influence of the change of marine tides and sings caused by the Moon. The slowdown is approximately 0.002 s per century. The accumulation of such, at first glance, imperceptible abnormalities means, however, that since the beginning of our era, until today, the total slowdown is about 3.5 hours.

Appeal around the Sun is the second major movement of our planet. Earth moves along an elliptical orbit, i.e. Orbit has the form of an ellipse. When the moon is in close proximity to the Earth and falls into its shadow, eclipses occur. The average distance between the Earth and the Sun is approximately 149.6 million kilometers. In astronomy, an unit of measurement of distances inside the solar system is used; It is called "Astronomical unit" (A.E.). The speed with which the Earth moves in orbit is approximately 107,000 km / h. The angle formed by the earth's axis and the plane of the ellipse is approximately 66 ° 33, and stored on the entire orbit.

From the point of view of the observer located on Earth, the appeal leads to the visible movement of the sun on ecliptic through the stars and constellations presented in the zodiac. In fact, the Sun also passes through the constellation of the serpent, but it does not apply to the zodiacal circle.

Seasons

The change of seasons is a consequence of the earth's appeal around the Sun. The cause of seasonal changes is the slope of the axis of rotation of the Earth to the plane of its orbit. Moving along the elliptical orbit, the land in January is located in the most close to the sun point (perigelium), and in July, in the most distant point from him - Aflia. The reason for changing the time of the year is the tilt of the orbit, as a result of which the Earth bends to the Sun. one hemispheres, then another and, accordingly, it receives a different amount of sunlight. In the summer, the sun reaches the highest point of the ecliptic. This means that the sun exercises over the horizon the longest movement per day, and the duration of the day is maximum. In winter, on the contrary, the sun is low above the horizon, the sun's rays fall on the ground not straight, but oblique. The duration of the day is short.

Depending on the time of year, different parts of the planet are under the action of sunlight. Rays are perpendicular to the tropics during the solstice.

Seasons in the northern hemisphere

Annual movement of land

The definition of the year, the main calendar unit, is not as simple as it seems at first glance, and depends on the chosen reference system.

The time interval for which our planet makes a complete turnover in orbit around the Sun is called a year. Nevertheless, the duration of the year varies depending on whether it is taken for the point of reference when measured infinitely distant star or The sun.

In the first case mean "Starry year" ("Siderician Year") . He is equal 365 days 6 o'clock 9 minutes and 10 seconds And it is the time required for the full circulation of the Earth around the Sun.

But if we measure the time required in order for the sun again at the same point in the system of celestial coordinates, for example, at the point of spring equinox, then we will receive duration "Sunny year" 365 days 5 hours 48 minutes 46 seconds . The difference between the star and a sunny year is due to the precession of the equinoxpies, each year the days of the equinox (and, accordingly, the sun standing) occur "earlier" approximately 20 minutes. Compared to the previous year. Thus, the Earth bypasses its orbit just faster than the sun in his visible movement through the stars returns to the point of spring equinox.

Considering that the duration of the year is in close connection with the Sun, when drawing up calendars as a basis is taken precisely "Sunny year" .

Also, in astronomy, instead of the usual astronomical time, determined by the period of rotation of the Earth relative to the stars, a new uniformly current time, not related to the rotation of the Earth and called with ephemeride time.

Read more about ephemeride in the section: .

Dear visitors!

In astronomy, earth orbit is the movement of the Earth around the Sun with an average distance of 149,597,870 km. The land completely envelopes the sun every 365.2563666 days (1 star year). With this movement, the Sun is moved relative to the stars per 1 ° per day (or the diameter of the sun or the moon every 12 hours) to the east, as can be seen from the ground. In order to make a complete turn around its land axle, it takes 24 hours, after which the sun returns to its meridian. The orbital speed of the Earth when driving around the Sun on average is 30 km per second (108,000 km per hour), which is fast enough to cover the diameter of the Earth (about 12700 km) in 7 minutes or the distance to the Moon (384,000 km) for 4 hours .

When studying the northern poles of the Sun and the Earth, it was found that the Earth rotates towards the Sun in the direction counterclockwise. Also, the sun and the land rotate counterclockwise around their axes.

Earth orbit, rich sun, passes between approximately 940 million km in one year.

Story study

Heliocentrism is the theory, which says that the sun is located in the center of the solar system. Historically, Heliocentrism is contrary to geocentrism, which states that the land is located in the center of the Solar System. In the 16th century, Nikolai Copernicus presented the full work on the heliocentric model of the universe, which was largely similar to the Geocentric model of the Almagest Ptolemy, represented in the 2nd century. This Copernikovsky revolution argued that the retrograde movement of the planets only seemed so, and was not obvious.

Impact on the ground

Because of the tilt axis of the earth (also known as the slope of the ecliptic) the slope of the trajectory of the sun in the sky (as can be seen on the surface of the earth) changes throughout the year. When observing the northern latitude, when the North Pole is tilted to the Sun, you can see that the day becomes longer, and the sun goes back above. This position leads to an increase in average temperatures, since the amount of sunlight reaching the surface increases. When the North Pole deviates from the Sun, then in general the temperature becomes cooler. In extreme cases, when the sun's rays do not reach the northern polar circle, during a certain period during the day there is no light (this phenomenon is called polar night). Such changes in the climate (due to the direction of inclination of the axis of the Earth) occur depending on the seasons.

Events in orbit

For one astronomical agreement, four seasons are determined by the solstice - an orbital point with a maximum tilt of the axis to the Sun or from it and the equinox, in which the direction of inclination and the direction of the sun is perpendicular to each other. In the northern hemisphere, the winter solstice occurs on December 21, the summer solstice - July 21, the spring equinox is March 20 and the autumn equinox on September 23. The tilt of the axis in the southern hemisphere is completely opposite to its direction in the northern hemisphere. Therefore, the seasons in the south are opposite to the North.

In our time, the Earth passes the perieghelium on January 3, and through Aflia July 4 (for other eras, see Precessions and Milankovich cycles). The change in the direction of the Earth and the Sun leads to an increase in solar energy by 6.9%, which reaches the Earth in perihelials relative to Aplia. Since the southern hemisphere bends to the Sun at about the same time when the earth reaches the most nearest point from the sun, during the year the southern hemisphere gets a little more solar energy than the northern hemisphere. However, such an effect is less significant than the overall change in energy due to an inclination of the axis: most of the resulting energy absorb the water of the southern hemisphere.

The Hilla (gravitational sphere of influence) of the Earth within a radius is 1500,000 kilometers. This is the maximum distance where the gravitational effect of the land is stronger than the power of more distant planets and the sun. Objects rotating around the Earth should fall into this radius, otherwise they can become unrelated due to the gravitational excitement of the Sun.

The following diagram shows the ratio between the solstice line and the line of aspida of the ELLIPTIC Earth orbit. The orbital ellipse (the eccentricity is exaggerated for the effect) is shown in the six images of the Earth in the perihelion (perihali perihal, the nearest point to the Sun) from 2 to 5 January: here you can also see Martov Equinox from March 20 to 21, the point of the June Solstice from June 20 to 21, Aflia (Apocenter - Far Dot from the Sun) From July 4 to July 7, September equinox from September 22 to September 23 and December Solstice from December 21 to December 22. Please note that the diagram shows the exaggerated form of the earth's orbit. In fact, the path of the earth orbit is not such an eccentric, as shown in the diagram.