The earth is constantly in motion, revolving around the sun and around its own axis. This movement and the constant tilt of the Earth's axis (23.5°) determines many of the effects that we observe as normal phenomena: night and day (due to the rotation of the Earth on its axis), the change of seasons (due to the tilt of the Earth's axis), and different climate in different areas. Globes can be rotated and their axis has an inclination like the Earth's axis (23.5 °), so with the help of a globe you can trace the movement of the Earth around its axis quite accurately, and with the help of the "Earth - Sun" system you can trace the movement of the Earth around the Sun.

Rotation of the Earth around its axis

The earth rotates on its own axis from west to east (counterclockwise as viewed from the North Pole). It takes the Earth 23 hours, 56 minutes, and 4.09 seconds to complete one complete revolution on its own axis. Day and night are due to the rotation of the earth. The angular velocity of the Earth's rotation around its axis, or the angle by which any point on the Earth's surface turns, is the same. It is 15 degrees in one hour. But the linear speed of rotation anywhere on the equator is approximately 1,669 kilometers per hour (464 m/s), decreasing to zero at the poles. For example, the rotation speed at a latitude of 30° is 1445 km/h (400 m/s).
We do not notice the rotation of the Earth for the simple reason that all the objects around us are moving in parallel and simultaneously with us at the same speed and there are no "relative" movements of objects around us. If, for example, a ship moves evenly, without acceleration and deceleration across the sea in calm weather, without waves on the surface of the water, we will not feel at all how such a ship moves if we are in a cabin without a porthole, since all objects inside the cabin will be move in parallel with us and the ship.

Movement of the Earth around the Sun

While the Earth rotates on its own axis, it also rotates around the Sun from west to east counterclockwise, as viewed from the north pole. It takes the Earth one sidereal year (about 365.2564 days) to complete one complete revolution around the Sun. The path of the Earth around the Sun is called the Earth's orbit. and this orbit is not perfectly round. The average distance from the Earth to the Sun is about 150 million kilometers, and this distance varies up to 5 million kilometers, forming a small oval orbit (ellipse). The point in the Earth's orbit closest to the Sun is called Perihelion. Earth passes this point in early January. The point in the Earth's orbit that is farthest from the Sun is called Aphelion. Earth passes this point in early July.
Since our Earth moves around the Sun in an elliptical trajectory, the orbital speed changes. In July, the speed is minimal (29.27 km/s) and after passing aphelion (upper red dot in the animation) it starts to accelerate, and in January the speed is maximum (30.27 km/s) and starts to slow down after passing perihelion (lower red dot). ).
While the Earth makes one revolution around the Sun, it covers a distance equal to 942 million kilometers in 365 days, 6 hours, 9 minutes and 9.5 seconds, that is, we rush along with the Earth around the Sun at an average speed of 30 km per second (or 107 460 km per hour), and at the same time the Earth rotates around its own axis in 24 hours once (365 times in a year).
In fact, if we consider the movement of the Earth more scrupulously, then it is much more complicated, since various factors influence the Earth: the rotation of the Moon around the Earth, the attraction of other planets and stars.

Our planet is constantly in motion:

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

Earth's motion around its own axis

Rotation of the Earth around its axis(Fig. 1). An imaginary line is taken for the earth's axis, around which it rotates. This axis is deviated by 23 ° 27 "from the perpendicular to the plane of the ecliptic. The earth's axis intersects with the earth's surface at two points - the poles - the 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 makes a complete rotation around its axis in one day.

Rice. 1. Rotation of the Earth around its axis

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

sidereal day is the amount of time it takes the earth to rotate on its axis with respect to the stars. They are equal to 23 hours 56 minutes 4 seconds.

solar day is the amount of time it takes for the earth to rotate on its axis with respect 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 surface of the Earth moves 15° from its original position. But at the same time, the speed of movement is inversely proportional to the geographical latitude: at the equator it is 464 m / s, and at a latitude of 65 ° - only 195 m / s.

The rotation of the Earth around its axis in 1851 was proved by J. Foucault in his experiment. 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 turned out to be on new divisions. This can only happen if the surface of the Earth under the pendulum rotates. The position of the swing plane of the pendulum at the equator does not change, because the plane coincides with the meridian. The axial rotation of the Earth has important geographic implications.

When the Earth rotates, a 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 turning 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 inertial forces introduced to take into account the influence of the 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 deviates to the right, and in the Southern - 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 geographic 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 - east. 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, in the Southern - the left).

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 animate and inanimate nature. The daily rhythm is closely related to light and temperature conditions. The daily course of temperature, day and night breezes, etc. are well known. Daily rhythms also occur in wildlife - 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 proceeds in a daily rhythm.

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

Since 1884, a zone time account 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. Neighboring time zones differ by one hour. The boundaries of the belts are drawn taking into account political, administrative and economic boundaries.

The zero belt is Greenwich (by the name of the Greenwich Observatory near London), which runs on both sides of the zero meridian. The time of the zero, or initial, meridian is considered World time.

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

For a more rational use of daylight in summer in 1930, our country introduced maternity time, ahead of the zone by one hour. To do this, the hands of the clock 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, between April and October, the time has been moved forward one hour. This so-called summer time. It is introduced to save energy. In summer, Moscow is two hours ahead of standard time.

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 considered 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, around and helios- Sun) - the closest point of the orbit to the Sun - on January 3, the distance is 147 million km. It is winter in the Northern Hemisphere at this time. The farthest distance from the Sun in aphelion(from Greek. aro- away from and helios- Sun) - the greatest distance from the Sun - July 5. It is equal to 152 million km. At this time, it is summer in the Northern Hemisphere.

Rice. 4. 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 height of the Sun and the position of its sunrise and sunset change, the duration of the bright 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 a change 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 during the year. This is how the seasons change, which is typical for all planets that have an inclination of the axis of rotation 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, and the summer half-year - 186 days.

As a result of the movement of the Earth around the Sun and the inclination of the earth's axis to the plane of its orbit by 66.5 °, not only the change of seasons is observed on our planet, 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 according to the seasons in the Northern Hemisphere).

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

Equinox- the moment 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 inclination of the Earth's axis of rotation around the Sun on the equinoxes of March 20-21 and September 22-23 is neutral with respect to the Sun, and the parts of the planet facing it are uniformly 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 of passage by the center of the Sun of the points of the ecliptic, the most distant from the equator (solstice points). There are summer and winter solstices.

On the day of the summer solstice on June 21-22, the Earth takes 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, whose latitude is 23 ° 27 "All day and night, not only the polar regions are illuminated, but also the space beyond them up to latitude 66 ° 33" (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 ") turns out to be illuminated. Beyond it, on this day, the earth's surface is not illuminated.

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

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

At two parallels of the Earth on the days of the solstice, the Sun at noon is directly above the head of the observer, that is, at the zenith. Such parallels are called tropics. On the Tropic of the North (23° N), the Sun is at its zenith on June 22, on the Tropic of the South (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 expressed.

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 from the Arctic Circle near the pole, the longer the polar day. At the latitude of the Arctic Circle (66.5°) it lasts only one day, and at the Pole it lasts 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 dawn 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 belts. The hot belt lies between the Northern and Southern tropics (the Tropic of Cancer and the 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 zones of illumination. The seasons of the year are already expressed here: the farther from the tropics, the shorter and cooler the summer, the longer and colder the winter. The polar belts in the Northern and Southern Hemispheres are limited by the Arctic Circles. Here, the height of the Sun above the horizon during the year is low, 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, there are not only the change of seasons and the associated uneven illumination of the earth's surface across latitudes, but also a significant part of the processes in the geographical envelope: seasonal weather changes, the regime of rivers and lakes, the rhythm in the life of plants and animals, types and terms 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, the change in the 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 duration of the Julian year is longer than the astronomical one by 11 minutes 14 seconds, by the 16th century. an “error” of 10 days accumulated - the day of the vernal equinox did not come on March 21, but on March 11. This mistake was corrected in 1582 by a decree of Pope Gregory XIII. The count of days was moved forward by 10 days, and the day after October 4 was prescribed to be considered Friday, but not October 5, but October 15. The spring equinox was again returned to March 21, and the calendar became known as the Gregorian. It was introduced in Russia in 1918. However, it also has a number of drawbacks: uneven length of months (28, 29, 30, 31 days), inequality of quarters (90, 91, 92 days), inconsistency of numbers of months by days of the week.

The average distance from the Earth to the Sun is approximately 150 million kilometers. But since rotation of the earth around the sun occurs not in a circle, but in an ellipse, then at different times of the year the Earth is either a little further from the Sun, or a little closer to it.

In this real time-lapse photo, we see the path the Earth makes in 20-30 minutes relative to other planets and galaxies, rotating around its axis.

Change of seasons

It is known that in summer, in the hottest time of the year - in June, the Earth is about 5 million kilometers farther from the Sun than in winter, in the coldest season - in December. Hence, change of seasons happens not because the Earth is further or closer to the Sun, but for another reason.

The Earth, in its translational motion around the Sun, constantly maintains the same direction of its axis. And with the translational rotation of the Earth around the Sun in orbit, this imaginary earth's axis is always inclined to the plane of the earth's orbit. The reason for the change of seasons is precisely the fact that the Earth's axis is always inclined to the plane of the Earth's orbit in the same way.

Therefore, on June 22, when our hemisphere has the longest day of the year, the Sun also illuminates the North Pole, and the South Pole remains in darkness, since the sun's rays do not illuminate it. While summer in the Northern Hemisphere has long days and short nights, in the Southern Hemisphere, on the contrary, there are long nights and short days. There, therefore, it is winter, where the rays fall "obliquely" and have a low calorific value.

Time difference between day and night

It is known that the change of day and night occurs as a result of the rotation of the Earth around its axis, (more details:). BUT time difference between day and night depends on the rotation of the earth around the sun. In winter, December 22, when the longest night and the shortest day begin in the Northern Hemisphere, the North Pole is not illuminated by the Sun at all, it is “in darkness”, and the South Pole is illuminated. In winter, as you know, the inhabitants of the Northern Hemisphere have long nights and short days.

On March 21–22, the day is equal to the night, the vernal equinox; the same equinox autumn- happens on September 23rd. These days, the Earth occupies such a position in its orbit relative to the Sun that the sun's rays simultaneously illuminate both the North and South Poles, and they fall vertically on the equator (the Sun is at its zenith). Therefore, on March 21 and September 23, any point on the surface of the globe is illuminated by the Sun for 12 hours and is in darkness for 12 hours: day and night all over the world.

Climatic zones of the Earth

The rotation of the Earth around the Sun explains the existence of various climatic zones of the Earth. Due to the fact that the Earth has a spherical shape and its imaginary axis is always inclined to the plane of the earth's orbit at the same angle, different parts of the earth's surface are heated and illuminated by the sun's rays in different ways. They fall on separate areas of the earth's surface at different angles of inclination, and as a result, their calorific value in different zones of the earth's surface is not the same. When the Sun is low above the horizon (for example, in the evening) and its rays fall on the earth's surface at a small angle, they heat very little. On the contrary, when the Sun is high above the horizon (for example, at noon), its rays fall on the Earth at a large angle, and their calorific value increases.

Where the Sun is at its zenith on some days and its rays fall almost vertically, there is the so-called hot belt. In these places, animals have adapted to the hot climate (for example, monkeys, elephants and giraffes); tall palm trees, bananas grow there, pineapples ripen; there, under the shadow of the tropical Sun, spreading their crowns wide, there are gigantic baobab trees, the thickness of which in girth reaches 20 meters.

Where the sun never rises high above the horizon, there are two cold zones with poor flora and fauna. Here the animal and plant world is monotonous; large areas are almost devoid of vegetation. Snow covers boundless expanses. Between the hot and cold zones are two temperate belts, which occupy the largest areas of the surface of the globe.

The rotation of the Earth around the Sun explains the existence five climatic zones: one hot, two moderate and two cold.

The hot belt is located near the equator, and its conditional boundaries are the northern tropic (the tropic of Cancer) and the southern tropic (the tropic of Capricorn). The conditional boundaries of the cold belts are the northern and southern polar circles. Polar nights last there for almost 6 months. Days are the same length. There is no sharp boundary between the thermal zones, but there is a gradual decrease in heat from the equator to the South and North Poles.

Around the North and South Poles, huge spaces are occupied by continuous ice fields. In the oceans washing these inhospitable shores, colossal icebergs float (more:).

North and South Pole explorers

Reach North or South Pole has long been a daring dream of man. Brave and tireless Arctic explorers have made these attempts more than once.

So was the Russian explorer Georgy Yakovlevich Sedov, who in 1912 organized an expedition to the North Pole on the ship St. Foca. The tsarist government was indifferent to this great undertaking and did not provide adequate support to the brave sailor and experienced traveler. Due to lack of funds, G. Sedov was forced to spend the first winter on Novaya Zemlya, and the second on. In 1914, Sedov, together with two companions, finally made the last attempt to reach the North Pole, but the state of health and strength changed this daring man, and in March of that year he died on the way to his goal.

More than once, large expeditions on ships to the Pole were equipped, but even these expeditions failed to reach their goal. Heavy ice “fettered” the ships, sometimes breaking them and taking them away with their drift far in the direction opposite to the intended path.

Only in 1937, for the first time, was a Soviet expedition delivered to the North Pole by airships. The brave four - astronomer E. Fedorov, hydrobiologist P. Shirshov, radio operator E. Krenkel and the old sailor, expedition leader I. Papanin - lived on a drifting ice floe for 9 months. The huge ice floe sometimes gave cracks and collapsed. Brave researchers were more than once threatened with the danger of dying in the waves of the cold Arctic sea, but, despite this, they carried out their scientific research where no man had ever set foot before. Important research has been carried out in the fields of gravimetry, meteorology and hydrobiology. The fact of the existence of five climatic zones associated with the rotation of the Earth around the Sun has been confirmed.

The earth is always in motion. Although it seems that we are standing motionless on the surface of the planet, it is constantly rotating around its axis and the Sun. This movement is not felt by us, as it resembles flying in an airplane. We are moving at the same speed as the plane, so we don't feel like we are moving at all.

At what speed does the earth rotate on its axis?

The earth rotates once on its axis every 24 hours. (to be precise, in 23 hours 56 minutes 4.09 seconds or 23.93 hours). Since the circumference of the Earth is 40075 km, any object at the equator rotates at a speed of approximately 1674 km per hour or approximately 465 meters (0.465 km) per second (40075 km divided by 23.93 hours and we get 1674 km per hour).

At (90 degrees north latitude) and (90 degrees south latitude), the speed is effectively zero because the pole points rotate at a very slow speed.

To determine speed at any other latitude, simply multiply the cosine of latitude by the planet's rotational speed at the equator (1674 km per hour). The cosine of 45 degrees is 0.7071, so multiply 0.7071 by 1674 km per hour and get 1183.7 km per hour.

The cosine of the required latitude is easy to determine using a calculator or look in the cosine table.

Earth rotation speed for other latitudes:

• 10 degrees: 0.9848×1674=1648.6 km per hour;
• 20 degrees: 0.9397×1674=1573.1 km per hour;
• 30 degrees: 0.866×1674=1449.7 km/h;
• 40 degrees: 0.766×1674=1282.3 km per hour;
• 50 degrees: 0.6428×1674=1076.0 km per hour;
• 60 degrees: 0.5×1674=837.0 km/h;
• 70 degrees: 0.342×1674=572.5 km per hour;
• 80 degrees: 0.1736×1674=290.6 km per hour.

Cyclic braking

Everything is cyclical, even the speed of rotation of our planet, which geophysicists can measure to within milliseconds. The Earth's rotation typically has five-year cycles of deceleration and acceleration, and the final year of the deceleration cycle is often correlated with a surge in earthquakes around the world.

Since 2018 is the last year in a slowdown cycle, scientists expect an increase in seismic activity this year. Correlation is not causation, but geologists are always looking for tools to try and predict when the next big earthquake is going to happen.

Oscillation of the earth's axis

The earth wobbles slightly as it rotates as its axis drifts at the poles. It has been observed that the drift of the earth's axis has accelerated since 2000, moving eastward at a rate of 17 cm per year. Scientists have found that the axis is still moving east instead of moving back and forth due to the combined effect of the melting of Greenland and, as well as the loss of water in Eurasia.

Axis drift is expected to be particularly sensitive to changes occurring at 45 degrees north and south latitude. This discovery led to the fact that scientists were finally able to answer the long-standing question of why the axis drifts at all. The wobble to the East or West was caused by dry or wet years in Eurasia.

Even in ancient times, observing the starry sky, people noticed that during the day the sun, and in the night sky - almost all the stars - repeat their path from time to time. This suggested that there were two reasons for this phenomenon. Either it takes place against the background of a fixed starry sky, or the sky revolves around the Earth. Claudius Ptolemy, an outstanding ancient Greek astronomer, scientist and geographer, seemed to have solved this issue by convincing everyone that the Sun and the sky revolve around the motionless Earth. Despite the fact that she could not explain, many resigned themselves to this.

The heliocentric system, based on another version, won its recognition in a long and dramatic struggle. Giordano Bruno died at the stake, the aged Galileo recognized the "correctness" of the Inquisition, but "... it still spins!"

Today, the rotation of the Earth around the Sun is considered fully proven. In particular, the movement of our planet in a near-solar orbit is proved by the aberration of starlight and parallactic displacement with a periodicity equal to one year. Today it has been established that the direction of rotation of the Earth, more precisely, its barycenter, along the orbit coincides with the direction of its rotation around its axis, that is, it occurs from west to east.

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

The rotation of the Earth around the Sun, like other planets, takes place in an elliptical orbit. Therefore, once a year, on January 3, the Earth is as close as possible to the Sun and once, on July 5, it moves away from it at the greatest distance. The difference between perihelion (147 million km) and aphelion (152 million km), compared to the distance from the Sun to the Earth, is very small.

Moving in a near-solar orbit, our planet makes 30 km per second, and the revolution of the Earth around the Sun is completed within 365 days 6 hours. This is the so-called sidereal, or stellar, year. For practical convenience, it is customary to consider 365 days a year. The "additional" 6 hours in 4 years add up to 24 hours, that is, one more day. These (running, extra) days are added to February once every 4 years. Therefore, in our calendar, 3 years include 365 days, and a leap year - the fourth year, contains 366 days.

The Earth's own rotation axis is tilted to the orbital plane by 66.5°. In this regard, during the year, the sun's rays fall on every point on the earth's surface under

corners. Thus, at different times of the year, points on different sites receive at the same time an unequal amount of light and heat. Because of this, in temperate latitudes, the seasons have a pronounced character. At the same time, throughout the year, the sun's rays at the equator fall on the earth at the same angle, so the seasons there differ slightly from each other.