The speed of the earth around the sun is km per second. Planets of the Solar System: eight and one. Does the speed of the Earth's movement around its axis change?

Our planet is in constant motion. Together with the Sun, it moves in space around the center of the Galaxy. And she, in turn, moves in the Universe. But the rotation of the Earth around the Sun and its own axis plays the greatest importance for all living things. Without this movement, conditions on the planet would be unsuitable for supporting life.

solar system

According to scientists, the Earth as a planet in the solar system was formed more than 4.5 billion years ago. During this time, the distance from the luminary practically did not change. The speed of the planet's movement and the gravitational force of the Sun balanced its orbit. It's not perfectly round, but it's stable. If the gravity of the star had been stronger or the speed of the Earth had noticeably decreased, then it would have fallen into the Sun. Otherwise, sooner or later it would fly into space, ceasing to be part of the system.

The distance from the Sun to the Earth makes it possible to maintain 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 at a greater distance, the temperature on it would become negative. If it were closer, all the water would evaporate, since the thermometer would exceed the boiling point.

The path of a planet around a star is called an orbit. The trajectory of this flight is not perfectly circular. It has an ellipse. The maximum difference is 5 million km. The closest point of the orbit to the Sun is at a distance of 147 km. It's called perihelion. Its land passes in January. In July, the planet is at its maximum distance from the star. The greatest distance is 152 million km. This point is called aphelion.

The rotation of the Earth around its axis and the Sun ensures a corresponding change in daily patterns and annual periods.

For humans, the movement of the planet around the center of the system is imperceptible. This is because the mass of the Earth is enormous. Nevertheless, every second we fly about 30 km in space. This seems unrealistic, but these are the calculations. On average, it is believed that the Earth is located at a distance of about 150 million km from the Sun. It makes one full revolution around the star in 365 days. The distance traveled per 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 through space in an elliptical orbit at a speed of 107,000 km/hour. The direction of rotation is from west to east, that is, counterclockwise.

The planet does not complete a 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 “accumulates”; 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 average value. This is due to the elliptical orbit. The difference between the values ​​is most pronounced at the perihelion and aphelion points and is 1 km/sec. These changes are invisible, since we and all the objects around us move in the same coordinate system.

Change of seasons

The Earth's rotation around the Sun and the tilt of the planet's axis make the seasons possible. This is less noticeable at the equator. But closer to the poles, the annual cyclicity 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 orbital points. At the same time, alternately twice during the six-month cycle they find themselves further or closer to it (in December and June - the days of the solstices). Accordingly, in a place where the surface of the planet warms up better, the ambient temperature there is higher. The period in such a territory is usually called summer. In the other hemisphere it is noticeably colder at this time - it is winter there.

After three months of such movement with a periodicity 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, autumn and spring begin.

Earth's axis

Our planet is a rotating ball. Its movement is carried out around a conventional axis and occurs according to the principle of a top. By resting its base on the plane in an untwisted state, it will maintain balance. When the rotation speed weakens, the top falls.

The earth has no support. The planet is affected by the gravitational forces of the Sun, Moon and other objects of the system and the Universe. Nevertheless, it maintains a constant position in space. The speed of its rotation, obtained during the formation of the core, is sufficient to maintain relative equilibrium.

The earth's axis does not pass perpendicularly through the globe of the planet. It is inclined at an angle of 66°33´. The rotation of the Earth around its axis and the Sun makes possible the change of seasons. The planet would “tumble” in space if it did not have a strict orientation. There would be no talk 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 throughout the year. During the day it alternates between day and night. If you look at the Earth's North Pole from space, you can see how it rotates counterclockwise. It completes a full rotation in approximately 24 hours. This period is called a day.

The speed of rotation determines the speed of day and night. In one hour, the planet rotates approximately 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/sec. Closer to the poles this figure decreases. At the thirtieth latitude, the linear speed will already be 1445 km/h (400 m/sec).

Due to its axial rotation, the planet has a somewhat compressed shape at the poles. This movement also “forces” moving objects (including air and water flows) to deviate from their original direction (Coriolis force). Another important consequence of this rotation is the ebb and flow of tides.

the change of night and day

A spherical object is only half illuminated by a single light source at a certain moment. In relation to our planet, in one part of it there will be daylight at this moment. The unlit part will be hidden from the Sun - it is night there. Axial rotation makes it possible to alternate these periods.

In addition to the light regime, the conditions for heating the surface of the planet with the energy of the luminary change. This cyclicality is important. The speed of change of light and thermal regimes is carried out relatively quickly. In 24 hours, the surface does not have time to either heat up excessively or cool down below the optimal level.

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 a constant orbit, the planet would not remain 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 origin and preservation of life.

Uneven rotation

Throughout its history, humanity 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 is influenced to a certain extent by the ellipse of the orbit and other planets in the system.

Another feature is the change in the length of the day. The Earth's axial rotation occurs unevenly. There are several main reasons. Seasonal variations associated with atmospheric dynamics and precipitation distribution are important. In addition, a tidal wave directed against the direction of the planet’s movement constantly slows it down. This figure is negligible (for 40 thousand years per 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 Earth's rotation 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 influence human life processes and natural phenomena in hydrometeorology and other areas.

Our planet is in constant motion, it rotates around the Sun and its own axis. The Earth's axis is an imaginary line drawn from the North to the South Pole (they remain motionless during rotation) at an angle of 66 0 33 ꞌ relative to the plane of the Earth. People cannot notice the moment of rotation, because all objects move in parallel, their speed is the same. It would look exactly the same as if we were sailing on a ship and did not notice the movement of objects and objects on it.

A full revolution around the axis is completed within one sidereal day, consisting of 23 hours 56 minutes and 4 seconds. During this period, first one or the other side of the planet turns towards the Sun, receiving different amounts of heat and light from it. In addition, the rotation of the Earth around its axis affects its shape (flattened poles are the result of the planet’s rotation around its axis) and the deviation when bodies move in the horizontal plane (rivers, currents and winds of the Southern Hemisphere deviate to the left, of the Northern Hemisphere to the right).

Linear and angular rotation speed

(Earth Rotation)

The linear speed of rotation of the Earth around its axis is 465 m/s or 1674 km/h in the equator zone; as you move away from it, the speed gradually slows down, at the North and South Poles it is zero. For example, for citizens of the equatorial city of Quito (the capital of Ecuador in South America), the rotation speed is exactly 465 m/s, and for Muscovites living at the 55th parallel north of the equator, it is 260 m/s (almost half as much) .

Every year, the speed of rotation around the axis decreases by 4 milliseconds, which is due to the influence of the Moon on the strength of sea and ocean tides. The Moon's gravity "pulls" the water in the opposite direction to the Earth's axial rotation, creating a slight frictional force that slows the rotation speed by 4 milliseconds. The speed of angular rotation remains the same everywhere, its value is 15 degrees per hour.

Why does day give way to night?

(The change of night and day)

The time for a complete revolution of the Earth around its axis is one sidereal day (23 hours 56 minutes 4 seconds), during this time period the side illuminated by the Sun is first “in the power” of the day, the shadow side is under the control of the night, and then vice versa.

If the Earth rotated differently and one side of it was constantly turned towards the Sun, then there would be a high temperature (up to 100 degrees Celsius) and all the water would evaporate; on the other side, on the contrary, frost would rage and the water would be under a thick layer of ice. Both the first and second conditions would be unacceptable for the development of life and the existence of the human species.

Why do the seasons change?

(Change of seasons on Earth)

Due to the fact that the axis is tilted relative to the earth's surface at a certain angle, its parts receive different amounts of heat and light at different times, which causes the change of seasons. According to the astronomical parameters necessary to determine the time of year, certain points in time are taken as reference points: for summer and winter these are the Solstice Days (June 21 and December 22), for spring and autumn - the Equinoxes (March 20 and September 23). From September to March, the Northern Hemisphere faces the Sun for less time and, accordingly, receives less heat and light, hello winter-winter, the Southern Hemisphere at this time receives a lot of heat and light, long live summer! 6 months pass and the Earth moves to the opposite point of its orbit and the Northern Hemisphere receives more heat and light, the days become longer, the Sun rises higher - summer comes.

If the Earth were located in relation to the Sun in an exclusively vertical position, then the seasons would not exist at all, because all points on the half illuminated by the Sun would receive the same and uniform amount of heat and light.

Our planet is constantly in motion:

• rotation around its own axis, movement around the Sun;
• rotation with the Sun around the center of our galaxy;
• movement relative to the center of the Local Group of galaxies and others.

Movement of the Earth around its own axis

Rotation of the Earth around its axis(Fig. 1). The earth's axis is taken to be an imaginary line around which it rotates. This axis is deviated by 23°27" from the perpendicular to the ecliptic plane. The Earth's axis intersects with the Earth's surface at two points - the poles - North and South. When viewed from the North Pole, the Earth's rotation occurs counterclockwise, or, as is commonly believed, with west to east. The planet completes a full rotation around its axis in one day.

Rice. 1. Rotation of the Earth around its axis

A day is a unit of time. There are sidereal and solar days.

Sidereal day- this is the period of time during which the Earth will turn around its axis in relation to the stars. They are equal to 23 hours 56 minutes 4 seconds.

Sunny day- this is the period of time during which the Earth turns around its axis in relation to the Sun.

The angle of rotation of our planet around its axis is the same at all latitudes. In one hour, each point on the Earth's surface moves 15° from its original position. But at the same time, the speed of movement is inversely proportional to the geographic latitude: at the equator it is 464 m/s, and at a latitude of 65° it is only 195 m/s.

The rotation of the Earth around its axis in 1851 was proved in his experiment by J. Foucault. In Paris, in the Pantheon, a pendulum was hung under the dome, and under it a circle with divisions. With each subsequent movement, the pendulum ended up on new divisions. This can only happen if the surface of the Earth under the pendulum rotates. The position of the pendulum's swing plane at the equator does not change, because the plane coincides with the meridian. The Earth's axial rotation has important geographical consequences.

When the Earth rotates, centrifugal force arises, which plays an important role in shaping the shape of the planet and reduces the force of gravity.

Another of the most important consequences of axial rotation is the formation of a rotational force - Coriolis forces. In the 19th century it was first calculated by a French scientist in the field of mechanics G. Coriolis (1792-1843). This is one of the inertia forces introduced to take into account the influence of rotation of a moving frame of reference on the relative motion of a material point. Its effect can be briefly expressed as follows: every moving body in the Northern Hemisphere is deflected to the right, and in the Southern Hemisphere - to the left. At the equator, the Coriolis force is zero (Fig. 3).

Rice. 3. Action of the Coriolis force

The action of the Coriolis force extends to many phenomena of the geographical envelope. Its deflecting effect is especially noticeable in the direction of movement of air masses. Under the influence of the deflecting force of the Earth's rotation, the winds of temperate latitudes of both hemispheres take a predominantly western direction, and in tropical latitudes - eastern. A similar manifestation of the Coriolis force is found in the direction of movement of ocean waters. The asymmetry of river valleys is also associated with this force (the right bank is usually high in the Northern Hemisphere, and the left bank in the Southern Hemisphere).

The rotation of the Earth around its axis also leads to the movement of solar illumination across the earth's surface from east to west, i.e., to the change of day and night.

The change of day and night creates a daily rhythm in living and inanimate nature. The circadian rhythm is closely related to light and temperature conditions. The daily variation of temperature, day and night breezes, etc. are well known. Circadian rhythms also occur in living nature - photosynthesis is possible only during the day, most plants open their flowers at different hours; Some animals are active during the day, others at night. Human life also flows in a circadian rhythm.

Another consequence of the Earth’s rotation around its axis is the time difference at different points on our planet.

Since 1884, zone time was adopted, that is, the entire surface of the Earth was divided into 24 time zones of 15° each. Behind standard time take the local time of the middle meridian of each zone. Time in neighboring time zones differs by one hour. The boundaries of the belts are drawn taking into account political, administrative and economic boundaries.

The zero belt is considered to be the Greenwich belt (named after the Greenwich Observatory near London), which runs on both sides of the prime meridian. The time of the prime, or prime, meridian is considered Universal time.

Meridian 180° is taken as international date line- a conventional line on the surface of the globe, on both sides of which the hours and minutes coincide, and the calendar dates differ by one day.

For a more rational use of daylight in summer, in 1930, our country introduced maternity time, one hour ahead of the time zone. To achieve this, the clock hands were moved forward one hour. In this regard, Moscow, being in the second time zone, lives according to the time of the third time zone.

Since 1981, from April to October, time has been moved forward one hour. This is the so called summer time. It is introduced to save energy. In summer, Moscow is two hours ahead of standard time.

The time of the time zone in which Moscow is located is Moscow.

Movement of the Earth around the Sun

Rotating around its axis, the Earth simultaneously moves around the Sun, going around the circle in 365 days 5 hours 48 minutes 46 seconds. This period is called astronomical year. For convenience, it is believed that there are 365 days in a year, and every four years, when 24 hours out of six hours “accumulate”, there are not 365, but 366 days in a year. This year is called leap year and one day is added to February.

The path in space along which the Earth moves around the Sun is called orbit(Fig. 4). The Earth's orbit is elliptical, so the distance from the Earth to the Sun is not constant. When the Earth is in perihelion(from Greek peri- near, near and helios- Sun) - the point of orbit closest to the Sun - on January 3, the distance is 147 million km. It is winter in the Northern Hemisphere at this time. Greatest distance from the Sun in aphelion(from Greek aro- away from and helios- Sun) - greatest distance from the Sun - July 5th. It is equal to 152 million km. It's summer in the Northern Hemisphere at this time.

Rice. 4. The movement of the Earth around the Sun

The annual movement of the Earth around the Sun is observed by the continuous change in the position of the Sun in the sky - the midday altitude of the Sun and the position of its sunrise and sunset change, the duration of the light and dark parts of the day changes.

When moving in orbit, the direction of the earth's axis does not change; it is always directed towards the North Star.

As a result of changes in the distance from the Earth to the Sun, as well as due to the inclination of the Earth's axis to the plane of its movement around the Sun, an uneven distribution of solar radiation is observed on Earth throughout the year. This is how the change of seasons occurs, which is characteristic of all planets whose axis of rotation is tilted to the plane of its orbit. (ecliptic) different from 90°. The orbital speed of the planet in the Northern Hemisphere is higher in winter and lower in summer. Therefore, the winter half-year lasts 179 days, and the summer half-year - 186 days.

As a result of the Earth's movement around the Sun and the tilt of the Earth's axis to the plane of its orbit by 66.5°, our planet experiences not only a change of seasons, but also a change in the length of day and night.

The rotation of the Earth around the Sun and the change of seasons on Earth are shown in Fig. 81 (equinoxes and solstices in accordance with the seasons in the Northern Hemisphere).

Only twice a year - on the days of the equinox, the length of day and night throughout the Earth is almost the same.

Equinox- the moment in time at which the center of the Sun, during its apparent annual movement along the ecliptic, crosses the celestial equator. There are spring and autumn equinoxes.

The tilt of the Earth's rotation axis around the Sun on the days of the equinoxes March 20-21 and September 22-23 turns out to be neutral with respect to the Sun, and the parts of the planet facing it are evenly illuminated from pole to pole (Fig. 5). The sun's rays fall vertically at the equator.

The longest day and shortest night occur on the summer solstice.

Rice. 5. Illumination of the Earth by the Sun on the days of the equinox

Solstice- the moment the center of the Sun passes the points of the ecliptic most distant from the equator (solstice points). There are summer and winter solstices.

On the day of the summer solstice, June 21-22, the Earth occupies a position in which the northern end of its axis is tilted towards the Sun. And the rays fall vertically not on the equator, but on the northern tropic, the latitude of which is 23°27". Not only the polar regions are illuminated around the clock, but also the space beyond them up to a latitude of 66°33" (the Arctic Circle). In the Southern Hemisphere at this time, only that part of it that lies between the equator and the southern Arctic Circle (66°33") is illuminated. Beyond it, the earth's surface is not illuminated on this day.

On the day of the winter solstice, December 21-22, everything happens the other way around (Fig. 6). The sun's rays are already falling vertically on the southern tropics. The areas that are illuminated in the Southern Hemisphere are not only between the equator and the tropics, but also around the South Pole. This situation continues until the spring equinox.

Rice. 6. Illumination of the Earth on the winter solstice

On two parallels of the Earth on solstice days, the Sun at noon is directly above the observer’s head, i.e. at the zenith. Such parallels are called the tropics. In the Northern Tropic (23° N) the Sun is at its zenith on June 22, in the Southern Tropic (23° S) - on December 22.

At the equator, day is always equal to night. The angle of incidence of the sun's rays on the earth's surface and the length of the day there change little, so the change of seasons is not pronounced.

Arctic Circles remarkable in that they are the boundaries of areas where there are polar days and nights.

Polar day- the period when the Sun does not fall below the horizon. The farther the pole is from the Arctic Circle, the longer the polar day. At the latitude of the Arctic Circle (66.5°) it lasts only one day, and at the pole - 189 days. In the Northern Hemisphere, at the latitude of the Arctic Circle, the polar day is observed on June 22, the day of the summer solstice, and in the Southern Hemisphere, at the latitude of the Southern Arctic Circle, on December 22.

polar night lasts from one day at the latitude of the Arctic Circle to 176 days at the poles. During the polar night, the Sun does not appear above the horizon. In the Northern Hemisphere at the latitude of the Arctic Circle, this phenomenon is observed on December 22.

It is impossible not to note such a wonderful natural phenomenon as white nights. White Nights- these are bright nights at the beginning of summer, when the evening dawn converges with the morning and twilight lasts all night. They are observed in both hemispheres at latitudes exceeding 60°, when the center of the Sun at midnight falls below the horizon by no more than 7°. In St. Petersburg (about 60° N) white nights last from June 11 to July 2, in Arkhangelsk (64° N) - from May 13 to July 30.

The seasonal rhythm in connection with the annual movement primarily affects the illumination of the earth's surface. Depending on the change in the height of the Sun above the horizon on Earth, there are five lighting zones. The hot zone lies between the Northern and Southern tropics (Tropic of Cancer and Tropic of Capricorn), occupies 40% of the earth's surface and is distinguished by the largest amount of heat coming from the Sun. Between the tropics and the Arctic Circles in the Southern and Northern Hemispheres there are moderate light zones. The seasons of the year are already pronounced here: the further from the tropics, the shorter and cooler the summer, the longer and colder the winter. The polar zones in the Northern and Southern Hemispheres are limited by the Arctic Circles. Here the height of the Sun above the horizon is low throughout the year, so the amount of solar heat is minimal. The polar zones are characterized by polar days and nights.

Depending on the annual movement of the Earth around the Sun, not only the change of seasons and the associated unevenness of illumination of the earth’s surface across latitudes, but also a significant part of the processes in the geographical envelope: seasonal changes in weather, the regime of rivers and lakes, rhythms in the life of plants and animals, types and timing of agricultural work.

Calendar.Calendar- a system for calculating long periods of time. This system is based on periodic natural phenomena associated with the movement of celestial bodies. The calendar uses astronomical phenomena - the change of seasons, day and night, and changes in lunar phases. The first calendar was Egyptian, created in the 4th century. BC e. On January 1, 45, Julius Caesar introduced the Julian calendar, which is still used by the Russian Orthodox Church. Due to the fact that the length of the Julian year is 11 minutes 14 seconds longer than the astronomical one, by the 16th century. an “error” of 10 days accumulated - the day of the vernal equinox did not occur on March 21, but on March 11. This error was corrected in 1582 by decree of Pope Gregory XIII. The counting of days was moved forward 10 days, and the day after October 4 was prescribed to be considered Friday, but not October 5, but October 15. The vernal equinox was again returned to March 21, and the calendar began to be called the Gregorian calendar. It was introduced in Russia in 1918. However, it also has a number of disadvantages: unequal length of months (28, 29, 30, 31 days), inequality of quarters (90, 91, 92 days), inconsistency of the numbers of months by day of the week.

The Earth, as we know, is constantly moving and this movement consists of its rotation around its axis and, in an ellipse, around the Sun. Thanks to these rotations, the seasons of the year change on our planet, and day gives way to night. What is the speed of rotation of the Earth?

Speed ​​of rotation of the Earth around its axis

If we consider the rotation of the Earth around its axis (of course, imaginary), then it makes one full revolution in 24 hours (more precisely, 23 hours, 56 minutes and 4 seconds), and it is generally accepted that at the equator the speed of this rotation is 1670 kilometers per hour. The rotation of our planet around its axis causes the change of day and night, and it is called diurnal.

The speed of rotation of the Earth around the Sun

The Earth rotates around our star along a closed elliptical trajectory, and completes a full revolution in 365 days, 5 hours, 48 ​​minutes and 46 seconds (this period of time is called a year). Hours, minutes and seconds make up another ¼ of a day, and over four years these “quarters” add up to a full day. Therefore, every fourth year consists of exactly 366 days and is called