Show the movement of the earth around the sun. Movement of the Earth in space (around the axis and the Sun). Summer and winter solstice

The daily rotation of the globe leads to a successive change of days and nights, and its orbital movement - to the alternation of the seasons and the change of the years themselves. These movements are the most important for earthlings, because they underlie astronomical methods of measuring time, but they are far from the only ones. Rushing along the circumsolar orbit at an average speed of about 30 km / s, our Earth performs many other very diverse movements.

As already mentioned, the axis of rotation of the Earth throughout the year retains a constant position in space, that is, it remains parallel to itself. And the northern end of this axis is directed to a fixed point in the sky near the North Star. And yet this is not entirely true. From century to century, the earth's axis, like the axis of a rotating top, slowly describes a cone, and this movement is caused by the same forces as the sea tides - the attraction of the Moon and the Sun. Only in this case they act not on the waters of the oceans, but on the masses of the Earth, which form its equatorial swelling.

As a result of a change in the direction of the earth's axis in space, the poles of the world slowly move among the stars in a small circle with a radius of 23 degrees 26 minutes of arc. It is at this angle that the axis of rotation of the Earth is deflected from the perpendicular to the plane of the earth's orbit (the plane of the ecliptic), and at the same angle the celestial equator is inclined to the plane of the ecliptic. Recall: the celestial equator is a large circle, 90 degrees from the poles of the world. It intersects the ecliptic at the points of the spring and autumn equinoxes. And as soon as the celestial pole moves, the equinoxes slowly move along the ecliptic towards the apparent movement of the Sun. As a result, spring arrives every year 20 minutes and 24 seconds earlier than the Sun has time to circle the entire ecliptic. Hence this phenomenon is called precession, which in Latin means "walking forward", or anticipation of the equinoxes.

Calculations have shown that the pole of the world makes a full circle on the celestial sphere in 25,770 years, that is, for almost 258 centuries. It is currently located about 46 arc minutes from Polaris. In 2103, he will approach the guiding star at a minimum distance of 27 arc minutes, and then, moving in the direction of the constellation Cepheus, will slowly move away from it.

For a long time, the North Pole of the world will not be "marked" by any bright star, and only about 7500 will pass at a distance of 2 degrees from Alpha Cepheus - a star of the second magnitude, competing in brightness with the Polar. Around the year 13,600, the brightest star in the northern sky, Vega, will act as a guiding light. Finally, the hour will come when, due to the further movement of the pole of the world, the royal Sirius will disappear from the skies of the northern latitudes, but the constellation of the Southern Cross will be visible.

Precession is complicated by the so-called nutation- slight swaying of the earth's axis. Like precession, it comes from the impact of our satellite on the equatorial bulge of the globe. As a result of the addition of these two movements, the movement of the celestial pole is not just in a circle, but along a slightly wavy curve. This is the fourth movement of the Earth.

The inclination of the Earth's axis of rotation to the plane of the orbit does not remain unchanged either. Our planet, although very slowly, is still "swaying", that is, the tilt of the earth's axis changes slightly. It is currently decreasing by about 0.5 arcseconds per year. If this decrease occurred constantly, then somewhere in the year 177,000 earthlings would have an excellent opportunity to live on a planet with a perpendicular axis. What changes would then take place in nature? On a globe with a perpendicular axis, there would no longer be any change of seasons. Its inhabitants could enjoy eternal spring! However, the range of fluctuations in the inclination of the Earth's axis of rotation is quite small - it does not exceed 2-3 degrees. The current "straightening" of the earth's axis will certainly stop, after which its inclination will increase.

Recall that the earth's orbit is an ellipse. And the shape of this ellipse is also subject to slow changes. It becomes more or less elongated. At present, the eccentricity of the earth's ellipse is 0.0167, and in 24,000 the earth's orbit will become almost a circle. Then, over the course of 40 millennia, the eccentricity will begin to increase again, and this will apparently continue as long as our planet itself exists. It's permanent change in the eccentricity of the earth's orbit can be considered as the sixth movement of the Earth.

The planets don't leave the Earth alone either. Depending on their mass and remoteness, they have a quite tangible effect on it. Thus, the major axis of the earth's orbit, connecting the nearest and the most distant points of the earth's path from the Sun (perihelion and aphelion), due to the combined gravity of the planets, slowly rotates. This cycle, lasting 21 thousand years, is secular change of perihelion and is the seventh movement of the Earth.

As a result of a change in the orientation of the earth's orbit, the timing of the passage of the earth through perihelion is slowly changing. And if now the Earth passes through perihelion in the first days of January, then around 11900 it will be at perihelion on the days of the summer solstice: then the winters will be especially cold, and the summer heat will reach its highest limit.

Popular books on astronomy say that "the moon revolves around the earth," but this expression is not entirely accurate. The fact is that not only the Earth attracts the Moon, but the Moon also attracts the Earth, and both celestial bodies move together, as one whole, around the common center of mass of the Earth-Moon system. The mass of the Moon is 81.3 times less than the mass of the Earth, and therefore this center is 81.3 times closer to the center of the Earth than to the center of the Moon. The average distance between their centers is 384,400 km. Using these data, we get: the center of mass of the Earth-Moon system is located at a distance of 4671 km from the center of the Earth towards the Moon, that is, at a distance of 1707 km under the Earth's surface (Equatorial radius of the Earth is 6378 km). It is around this center that the Earth and the Moon describe their orbits during the month. As a result, the Earth monthly either approaches the Sun or moves away from it, which causes small changes in the apparent diameter of the daylight. This is the eighth movement of the Earth.

Strictly speaking, the center of mass of the Earth-Moon system moves in a circumsolar orbit. Therefore, the Earth's trajectory should look like a slightly wavy line.

If only one Earth revolved around the Sun, then both celestial bodies would describe ellipses around the common center of mass of the Sun-Earth system. But the attraction of the Sun by other large planets causes this center to describe a very complex curve. And when all the planets are located on one side of the central luminary, they attract it to themselves especially strongly and displace the Sun, which is why the center of mass of the entire solar system goes beyond the limits of the solar ball. So there is another, ninth complication in the motion of the Earth.

Finally, our Earth itself easily responds to the attraction of other planets in the solar system. Indeed, according to Newton's law, all celestial bodies are attracted to each other with a force directly proportional to the product of their masses and inversely proportional to the square of their distance. This effect of the planets does not manifest itself in the best way - it deflects the Earth from its elliptical path around the Sun (from the Keplerian orbit) and causes all those irregularities in its orbital motion, which are called indignations or perturbations. The massive giant Jupiter and our neighbor Venus have the greatest perturbation on the Earth. The complication of the trajectory of the Earth's movement under the influence of the attraction of the planets constitutes its tenth movement.

It has long been established that stars move in space at tremendous speeds. Our Sun is no exception. Relative to the nearest stars, it flies in the direction of the constellation Hercules at a speed of about 20 km / s, taking with it all its satellites, including the Earth. The movement of the Earth in space, caused by the forward movement of the Sun, is the eleventh movement of our planet. Thanks to this endless flight, we forever leave that region of the sky where Sirius shines, and approach the unknown depths of the stars, where Vega sparkles brightly. Since the Earth was formed, it has never flown through familiar places and will never return to the point in the Universe where we are at the moment.

Let's depict the direction of the Sun's motion in space with a straight arrow. Then the point in the sky to which it flies will make an angle of about 40 degrees with the pole of the ecliptic. As you can see, our central luminary moves quite obliquely (in relation to the plane of the ecliptic), and the Earth, like a hawk or an eagle, describes a giant spiral around it...

If we could look at our galactic star "island" from the side and recognize our Sun among 200 billion stars, then we would establish that it moves around the center of the Galaxy at a speed of about 220 km / s and completes its path in about 230 million years . In this swift flight around the galactic core, together with the Sun, the entire solar system participates, and for our Earth this is the twelfth movement.

The flight of the Earth together with the Sun around the core of the Galaxy is supplemented by the thirteenth movement of our entire star system relative to the center of the cluster of galaxies closest to us.

It should be noted that the listed thirteen movements of the Earth are far from exhausting all of its possible movements. In the universe, every celestial body must participate in many different relative motions.

The Earth revolves around the Sun at an average speed of 29.76 km/sec. It travels all the way in orbit in 365 days 6 hours 9 minutes 9.6 seconds.
The most important consequence of the revolution of the Earth around the Sun with an almost unchanged position of its axis in space is the change of seasons.
The beginning of astronomical summer in the northern hemisphere - June 22 - summer solstice. In the southern hemisphere, astronomical winter begins at this time. On the summer solstice, the Earth is at aphelion. The axis of the Earth is inclined with its northern end to the Sun, and at noon the sun's rays fall vertically at a latitude of 23 ° 27 "N - on the northern tropic, on June 22, the Sun occupies the highest position in the year in the sky of all latitudes of the northern hemisphere. Latitudes north of 66 °33" s. sh. (from the Arctic Circle) are completely on the illuminated half of the Earth (Fig. 14, a), and the Sun does not set beyond the horizon here.
At all latitudes between the Arctic Circle and the Equator, the day is longer than the night. The illumination of the northern hemisphere on the day of the summer solstice is the greatest of the year. In the southern hemisphere on the day of the summer solstice, the Sun is especially low above the horizon. To the south of 66 ° 33 "S (from the southern polar circle) the polar night reigns, corresponding in duration to the polar day of the same latitudes of the northern hemisphere. At all latitudes between the southern polar circle and the equator, the day is shorter than the night. Illumination of the southern hemisphere per day summer solstice is the smallest of the year.

Continuously moving in orbit, on September 23, the Earth takes a position in which the light-separating line passes through the geographical poles, and day is equal to night on the whole Earth. This autumnal equinox. Both hemispheres (northern and southern) are equally illuminated on this day. September 23 - the beginning of astronomical autumn in the northern hemisphere and the beginning of astronomical spring - in the southern.
December 22, at winter solstice The Earth is at perihelion. The southern hemisphere faces the Sun, and astronomical summer begins there, while astronomical winter sets in in the northern hemisphere. The sun's rays at noon fall sheer on the southern tropic (23°27" S). The area near the south pole, bounded by the southern polar circle (66°33" S), is illuminated by the non-setting Sun; over the corresponding area in the northern hemisphere, the Sun does not rise. The illumination of the southern hemisphere is the greatest in the year, the northern hemisphere is the smallest. Like June 22, day equals night only at the equator.

On March 21, on the day of the vernal equinox, the Sun illuminates the Earth in the same way as on September 23: it stands at its zenith above the equator, and at all latitudes day is equal to night. In the northern hemisphere comes astronomical spring, in the southern - autumn.
The earth moves in orbit at different speeds. During the period when it is closest to the Sun (at perihelion), its speed is greatest. The lowest speed is during the passage of the Earth through aphelion. It follows that of all the seasons in the northern hemisphere, the longest is summer, and the shortest is winter, in the southern hemisphere it is vice versa. The differences in the length of the seasons are small. At present, spring in the northern hemisphere lasts 92.8 days, summer - 93.6, autumn - 89.8, winter - 89.0.

The mysterious and magical world of astronomy has attracted the attention of mankind since ancient times. People raised their heads up to the starry sky and asked eternal questions about why the stars change their position, why day and night come, why somewhere a blizzard howls, and somewhere in the desert plus 50 ...

The movement of the luminaries and calendars

Most of the planets in the solar system revolve around themselves. At the same time, they all make revolutions around the Sun. Some do it quickly and swiftly, others slowly and solemnly. Planet Earth is no exception, it is constantly moving in outer space. Even in ancient times, people, knowing the causes and mechanism of this movement, noticed a certain general pattern and began to draw up calendars. Even then, mankind was interested in the question of what is the speed of the Earth's revolution around the Sun.

The sun rises at sunrise

The movement of the Earth around its axis is an Earth day. And the complete passage of our planet in an ellipsoidal orbit around the star is a calendar year.

If you stand on the North Pole and draw an imaginary axis through the Earth to the South Pole, it turns out that our planet moves from west to east. Remember, even in the "Word of Igor's Campaign" it is said that "The sun rises at sunrise"? The east always meets the sun's rays before the west. That is why the new year in the Far East comes earlier than in Moscow.

At the same time, scientists determined that only two points on our planet are in a static position relative to the North and South Poles.

crazy speed

All other places on the planet are in perpetual motion. What is the speed of the Earth's revolution around the Sun? At the equator, it is the highest and reaches 1670 km per hour. Closer to the middle latitudes, for example, in Italy, the speed is already much lower - 1200 km per hour. And the closer to the poles, the smaller and smaller it is.

The period of rotation of the Earth around its axis is 24 hours. That's what scientists say. We call it easier - a day.

How fast does the earth revolve around the sun?

350 times faster than a racing car

In addition to rotating around its axis, the Earth also makes an ellipsoidal movement around a star called the Sun. With what speed Scientists have long ago calculated this indicator using complex formulas and calculations. The speed of the Earth around the Sun is 107 thousand kilometers per hour.

It's hard to even imagine these crazy, unrealistic numbers. For example, even the most racing car - 300 kilometers per hour - is 356 times less than the speed of the Earth in orbit.

It seems to us that it rises and rises, that the Earth is motionless, and the luminary makes a circle in the sky. For a very long time, humanity thought just that, until scientists proved that everything happens the other way around. Today, even a schoolboy knows what is happening in the world: the planets smoothly and solemnly move around the Sun, and not vice versa. The Earth revolves around the Sun, and not at all in the way that ancient people previously believed.

So, we found out that the speed of rotation of the earth around its axis and the Sun are respectively 1670 km per hour (at the equator) and 107 thousand kilometers per hour, respectively. Wow, we're flying!

solar and sidereal year

A full circle, or rather, an elliptical oval, the planet Earth goes around the Sun in 356 days 5 hours 48 minutes 46 seconds. Astronomers call these numbers the "astrological year". Therefore, to the question "What is the frequency of the Earth's revolution around the Sun?" we answer simply and concisely: "Year". This indicator remains unchanged, but for some reason, every four years we have a leap year in which there is one more day.

It's just that astronomers have long agreed that the extra 5 and a half hours are not counted every year, but have chosen the number of the astronomical year, a multiple of days. Thus, the year is 365 days. But so that over time there is no failure, so that natural rhythms do not shift in time, every four years a single extra day appears in the calendar in February. These quarter days for 4 years are "gathered" into a full day - and we celebrate a leap year. Thus, answering the question of what is the frequency of the Earth's revolution around the Sun, feel free to say that one year.

In the scientific world, there are concepts of "solar year" and "stellar (sidereal) year". The difference between them is about 20 minutes and it occurs due to the fact that our planet orbits faster than the Sun returns to the place that astronomers have identified as the vernal equinox. We already know the speed of the Earth's revolution around the Sun, and the total period of the Earth's revolution around the Sun is 1 year.

Days and years on other planets

The nine planets of the solar system have their own "concepts" about speed, about what a day is and what an astronomical year is.

The planet Venus, for example, revolves around itself for 243 Earth days. Can you imagine how much you can do there in one day? And how long is the night!

But on Jupiter, the opposite is true. This planet spins around its axis at a gigantic speed and manages to complete a 360-degree rotation in 9.92 hours.

The speed of the passage of the Earth in orbit around the Sun is a year (365 days), but Mercury is only 58.6 Earth days. On Mars, the planet closest to Earth, a day lasts almost as long as on Earth - 24 and a half hours, but a year is almost twice as long - 687 days.

The revolution of the Earth around the Sun is 365 days. Now let's multiply this figure by 247.7 and get one year on the planet Pluto. We have a millennium, and on the most distant planet in the solar system - only four years.

Here are such paradoxical values ​​and figures frightening in their scale.

Mysterious ellipse

To understand why the seasons periodically change on the planet Earth, why it is cold in our middle lane, and it is cold in winter, it is important not only to answer the question of how fast the Earth rotates around the Sun, and in what way. You also need to understand how she does it.

And she does this not in a circle, but in an ellipse. If we draw the orbit of the Earth around the Sun, then we will see that it is closest to the luminary in January, and farthest - in July. The closest point of the Earth's position in orbit is called perihelion, and the farthest point is called aphelion.

Since the earth's axis is not in a strictly vertical position, but is deviated by about 23.4 degrees, and with respect to the ellipsoidal orbit, the angle of inclination increases to 66.3 degrees, it turns out that in different positions the Earth exposes different sides to the Sun.

Due to the tilt of the orbit, the Earth turns to the star in different hemispheres, hence the change in weather. When winter rages in the Northern Hemisphere, hot summers bloom in the Southern Hemisphere. Six months later, the situation will change exactly the opposite.

Spin, earthly luminary!

Does the sun revolve around something? Of course! There are no absolutely motionless objects in space. All the planets, all their satellites, all comets and asteroids spin like clockwork. Of course, different celestial bodies have different speeds of rotation, and the angle of inclination of the axis, but still they are always in motion. And the Sun, which is a star, is no exception.

The solar system is not an independent closed space. It enters a huge spiral galaxy called the Milky Way. It, in turn, includes as many as 200 billion more stars. The sun moves in a circle around the center of this galaxy. The speed of rotation of the Sun around its axis and the Milky Way galaxy, scientists also calculated using long-term observations and mathematical formulas.

Today there is such data. The Sun completes its full cycle of circular motion around the Milky Way in 226 million years. In astronomical science, this figure is called the "galactic year". Moreover, if we imagine the surface of the galaxy as flat, then our luminary makes small fluctuations up and down, ending up alternately in the Northern and Southern hemispheres of the Milky Way. The frequency of such fluctuations is 30-35 million years.

Scientists believe that the Sun during the existence of the Galaxy managed to make 30 complete revolutions around the Milky Way. Thus, the Sun has lived only 30 galactic years so far. At least that's what scientists say.

Most scientists believe that life on Earth began 252 million years ago. Thus, it can be argued that the first living organisms on Earth appeared when the Sun made its 29th revolution around the Milky Way, that is, in the 29th year of its galactic life.

Body and gases move at different speeds

We learned a lot of interesting facts. We already know the rate of rotation of the Earth around the Sun, we found out what the astronomical and galactic year is, how fast the Earth and the Sun move in their orbits, and now we will determine how fast the Sun rotates around the axis.

The fact that the Sun rotates was noticed by ancient researchers. Similar spots periodically appeared on it, then disappeared, which made it possible to conclude that it rotates around its axis. But at what speed? Scientists, having the most modern methods of research, argued about this for a very long time.

After all, our luminary has a very complex composition. His body is solid. Inside is a solid core, around which is located a hot liquid mantle. Above it is hard bark. In addition to all this, the surface of the Sun is shrouded in hot gas, which is constantly burning. It is a heavy gas that consists mainly of hydrogen.

So, the body of the Sun itself rotates slowly, and this burning gas - quickly.

25 days and 22 years

The outer shell of the Sun makes a complete rotation around its axis in 27 and a half days. Astronomers have been able to determine this by observing sunspots. But this is an average. For example, at the equator they rotate faster and make a revolution around the axis in 25 days. At the poles, sunspots move at a rate of 31 to 36 days.

The body of the star itself rotates around its axis in 22.14 years. In general, in a hundred years of earthly life, the Sun will turn around its axis only four and a half times.

Why do scientists study the speed of rotation of our star so accurately?

Because it gives answers to many questions of evolution. After all, the star Sun is the source of life for all life on Earth. It is because of the flares on the Sun, according to many researchers, life appeared on Earth (252 million years ago). And it was because of the behavior of the Sun that dinosaurs and other reptiles died in ancient times.

Shine brightly on us, Sun!

People are constantly wondering if the Sun will exhaust its energy, will it go out? Of course, it will go out - there is nothing eternal in the world. And for such massive stars there is a time of birth, activity and decay. But so far the Sun is in the middle of the evolutionary cycle and it has enough energy. By the way, at the very beginning this star was less bright. Astronomers have determined that in the earliest stages of development, the brightness of the Sun was 70 percent lower than it is now.

The Earth, as you know, is constantly moving and this movement consists of its rotation around its axis and, along an ellipse, around the Sun. Thanks to these rotations, the seasons change on our planet, and the day is replaced by night. What is the speed of the earth's rotation?

The speed of the earth's rotation around its axis

If we consider the rotation of the Earth around its axis (of course, imaginary), then it makes one complete 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 a change of day and night, and it is called diurnal.

The speed of rotation of the Earth around the Sun

Around our luminary, the Earth rotates in a closed elliptical trajectory, and makes a complete 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 in four years such “quarters” add up to a full day. Therefore, every fourth year consists of exactly 366 days and is called

What is an orbit? How long does it take the earth to complete one revolution around the sun? How is the earth's axis positioned relative to the plane of the orbit?

1. Annual motion of the Earth. Like other planets, the Earth in its orbit rotates along a vicious circle around the Sun. But the Earth's orbit is not a regular, but a slightly elongated circle. Therefore, the Earth comes close to the Sun once a year (January 3), once a year it retreats to the farthest point of the orbit (July 5). The difference in distance between the closest (147 million km) and the farthest (152 million km) points is only 5 million km. This is a very small value compared to the average distance from the Earth to the Sun.
The Earth completes its orbit around the Sun in 365 days and 6 hours. It is generally accepted that there are 365 days in a year. The remaining 6 hours in total for 4 years is 24 hours or one day, which is added every 4 years to February. Then 3 years consist of 365 days, and the fourth year consists of 366 days. A year of 366 days is called leap year". February in such a year consists of 29 days, and in the remaining 3 years - of 28 days.

2. The difference in the distribution of heat on the surface of the Earth. The amount of heat coming to the Earth from the Sun directly depends on the position of the Earth's axis to the plane of the orbit. If the earth's axis is perpendicular to the plane of the orbit, then throughout the entire territory the day would be equal to the night during the year. Therefore, there would be no change of seasons. We would not know either summer or winter, or spring or autumn. In the equatorial zone, it would be hot summer all the time, in the middle zones - autumn or spring, closer to the poles - frosty winters would stand all year round.
In this regard, the natural belts and zones of the Earth would also be located differently than now.
Instead of the dense forests of North America and Eurasia, there would be an evergreen tundra. And the polar sides would be covered by an eternal shield of snow and ice.
But since the earth's axis is not located perpendicular to the plane of the orbit, but at an angle of 66.5 °, the solar heat is distributed on the surface of the Earth differently. The tilt of the earth's axis does not change as it moves around the sun. Therefore, at any point on the Earth, the angle of incidence of the sun's rays and the duration of the fall during the year are constantly changing. As a result, the amount of incoming heat changes and the seasons change.
In May-August, the Earth is directed towards the Sun by the northern hemisphere (Fig. 10), and more heat and light enter this side of the planet. Therefore, in the northern hemisphere it is summer, and in the southern hemisphere, on the contrary, it is winter.

Rice. 10. Change of seasons depending on the location of the Earth in orbit.

In December-February, the Earth is on the opposite side. Now the Sun heats more the southern hemisphere, there is summer, and in the northern hemisphere it is winter.
In September-November, March-May, the globe is turned sideways to the Sun, light and heat are distributed to both hemispheres. On one of the hemispheres - spring, on the other - autumn.

1. Why does the Earth approach the Sun once and move away once during the year?

2. How long does it take the Earth to complete one revolution around the Sun?

3. Why does February sometimes have 28 days and sometimes 29 days?

4. Why does the seasons change?

5. Which months correspond to winter, spring, summer and autumn in your area? 6. In what cases would there be no change of seasons?

7. It's autumn in your area. What season is it at this latitude in the southern hemisphere?

8. Draw a diagram of the location of the Earth in orbit in winter, summer, spring, autumn in your area.

Questions and tasks for summarizing the section "Earth - a planet of the solar system"
1. What celestial bodies are included in the solar system?

2. What is the importance of the location of the Earth in the solar system?

3. Why are there no conditions for life on other planets except the Earth?

4. Why are asteroids called minor planets?
5. Why did the ancient people consider the Earth at first flat, then disk-shaped?
6. What evidence is there for the spherical shape of the Earth? Name everything in full. Which of them have you observed yourself?

7. Why do we not notice the spherical shape of the Earth?

8. What effect does the spherical shape of the Earth have on the spread of heat?

9. What is the significance of the length of day and night for life on Earth?

10. What would happen on the Earth if it did not rotate around its axis?

11. At what age do people born on February 29 celebrate their birthday 1 time, and why?

12. Why and how does the seasons change on Earth?