Unified State Exam
Relationship between earth and sun. The size of the earth in comparison with the objects of our galaxy. Comparison with other celestial bodies

Relationship between earth and sun. The size of the earth in comparison with the objects of our galaxy. Comparison with other celestial bodies

Jupiter is the fifth planet from the Sun, the largest in the Solar System. The stripes and swirls on its surface represent cold, wind-driven clouds consisting of ammonia and water. The atmosphere is primarily composed of helium and hydrogen, and the famous Great Red Spot is a giant storm larger than Earth that lasts for hundreds of years. Jupiter is surrounded by 53 confirmed moons, as well as 14 temporary ones, for a total of 67. Scientists are most interested in the four largest objects discovered in 1610 by Galileo Galilei: Europa, Callisto, Ganymede and Io. Jupiter also has three rings, but they are very difficult to see and are not as elegant as Saturn's. The planet is named after the supreme Roman god.

Comparative sizes of the Sun, Jupiter and Earth

The planet is located an average of 778 million km from the star, which is 5.2. At this distance, light takes 43 minutes to reach the gas giant. The size of Jupiter compared to the Sun is so impressive that their barycenter extends beyond the surface of the star by 0.068 of its radius. The planet is much larger than Earth and much less dense. Their volume ratio is 1:1321, and their mass is 1:318. From the center to the surface, the size of Jupiter in km is 69911. This is 11 times wider than our planet. and the Earth can be compared as follows. If our planet was the size of a nickel, then the gas giant would be the size of a basketball. The size of the Sun and Jupiter in diameter are in a ratio of 10:1, and the mass of the planet is 0.001 that of the star.

Orbit and rotation

The gas giant has the shortest day in the solar system. Despite the size of Jupiter, a day on the planet lasts about 10 hours. A year, or revolution around the Sun, takes about 12 Earth years. The equator is tilted relative to its orbital path by only 3 degrees. This means that Jupiter rotates almost vertically and does not have the pronounced changes of seasons that occur on ours and other planets.

Formation

The planet formed along with the entire solar system 4.5 billion years ago, when gravity caused it to form from swirling dust and gas. Jupiter's size is due to the fact that it captured most of the mass remaining after the formation of the star. Its volume was twice that of the rest of the matter in other objects. solar system. It is made of the same material as a star, but the size of the planet Jupiter has not grown enough to launch thermonuclear reaction. About four billion years ago, the gas giant ended up in its current position in the outer solar system.

Structure

Jupiter's composition is similar to the sun's - mostly helium and hydrogen. Deep in the atmosphere, pressure and temperature rise, compressing hydrogen gas into liquid. Because of this, Jupiter has the largest ocean in the solar system, made of hydrogen instead of water. Scientists believe that at depths perhaps halfway to the center of the planet, the pressure becomes so great that electrons are squeezed out of the hydrogen atoms, turning it into a liquid, electrically conductive metal. The rapid rotation of a gas giant causes it electric currents, generating a strong magnetic field. It is still unknown whether the planet has a central core of hard material, or it is a thick, super-hot soup of iron and silicate minerals (like quartz) with temperatures up to 50,000 °C.

Surface

As a gas giant, Jupiter has no true surface. The planet consists mainly of rotating gases and liquids. Since the spacecraft will not be able to land on Jupiter, it will not be able to fly away unscathed. The extreme pressures and temperatures deep inside the planet will crush, melt and vaporize any ship that tries to reach it.

Atmosphere

Jupiter appears as a colorful tapestry of cloud streaks and spots. The gas planet likely has three separate cloud layers in its "sky" that together cover about 71 km. The top one consists of ammonia ice. The middle layer is most likely formed by crystals of ammonium hydrosulfide, and the inner layer is formed by water ice and steam. The bright colors of the thick streaks on Jupiter may be emissions of sulfur and phosphorus-containing gases rising from its interior. The planet's rapid rotation creates strong vortex flows, dividing the clouds into long dark belts and light zones.

The lack of a solid surface to slow them down allows Jupiter's spots to persist for many years. The planet is covered by more than a dozen prevailing winds, some reaching speeds of 539 km/h at the equator. The size of the Red Spot on Jupiter is twice as wide as the Earth. The formation of a twisted oval shape is observed on giant planet for more than 300 years. More recently, three small ovals formed a small Red Spot, about half the size of its larger cousin. Scientists do not yet know whether these ovals and stripes encircling the planet are shallow or extend far into the depths.

Potential for life

Jupiter's environment is probably not conducive to life as we know it. The temperatures, pressures and substances that characterize this planet are likely too extreme and lethal for living organisms. While Jupiter is an unlikely place for living things, the same cannot be said for some of its many moons. Europa is one of the most likely places to search for life in our solar system. There is evidence of a huge ocean beneath the icy crust that could support life.

Satellites

Many small ones and four large ones form the Solar System in miniature. The planet has 53 confirmed satellites, as well as 14 temporary ones, for a total of 67. These newly discovered satellites have been reported by astronomers and given a temporary designation by the International Astronomical Union. Once their orbits are confirmed, they will be included in the permanent ones.

The four largest moons - Europa, Io, Callisto and Ganymede - were first discovered in 1610 by astronomer Galileo Galilei using an early version of a telescope. These four moons represent one of the most exciting areas of research today. Io is the most volcanically active body in the Solar System. Ganymede is the largest of them (even larger than the planet Mercury). The second largest satellite from Jupiter - Callisto - has few small craters, which indicates small degree current surface activity. Ocean liquid water with the ingredients for life may lie beneath Europa's icy crust, making it a tempting subject for study.

Rings

Discovered in 1979 by NASA's Voyager 1, Jupiter's rings were a surprise because they were made up of small, dark particles that can only be seen against the sun. Data from the Galileo spacecraft suggest that the ring system may be formed by dust from interplanetary meteoroids that crashed into small inner satellites.

Magnetosphere

The magnetosphere of a gas giant is a region of space under the influence of a powerful magnetic field planets. It extends 1-3 million km towards the Sun, which is 7-21 times the size of Jupiter, and tapers into a tadpole-shaped tail at 1 billion km, reaching the orbit of Saturn. The huge magnetic field is 16-54 times more powerful than the earth's. It rotates with the planet and captures particles that have electric charge. Near Jupiter, it captures swarms of charged particles and accelerates them to very high energies, creating intense radiation that bombards nearby moons and can damage spacecraft. The magnetic field produces some of the most impressive in the solar system at the planet's poles.

Study

Although Jupiter has been known since ancient times, the first detailed observations of this planet were made by Galileo Galilei in 1610 using a primitive telescope. And only recently it was visited by spaceships, satellites and probes. The 10th and 11th Pioneers, 1st and 2nd Voyagers were the first to fly to Jupiter in 1970, and then Galileo was sent into orbit of the gas giant, and a probe was lowered into the atmosphere. Cassini took detailed photographs of the planet on its way to neighboring Saturn. The next Juno mission arrived at Jupiter in July 2016.

Significant Events

1610: Galileo Galilei made the first detailed observations of the planet.
1973: The first spacecraft, Pioneer 10, crossed and flew past the gas giant.
1979: The first and second Voyagers discovered new moons, rings and volcanic activity on Io.
1992: On February 8, Ulysses flew past Jupiter. Gravity changed the spacecraft's trajectory away from the ecliptic plane, placing the probe into a final orbit above the southern and north poles Sun.
1994: A collision with fragments of Comet Shoemaker-Levy occurred in the southern hemisphere of Jupiter.
1995-2003: The Galileo spacecraft dropped a probe into the atmosphere of the gas giant and conducted long-term observations of the planet, its rings and satellites.
2000: Cassini made its closest approach to Jupiter at a distance of about 10 million km, capturing a highly detailed color mosaic photograph of the gas giant.
2007: pictures taken spaceship NASA's New Horizons on its way to Pluto showed new prospects of atmospheric storms, rings, volcanic Io and icy Europa.
2009: Astronomers observed the fall of a comet or asteroid on the southern hemisphere of the planet.
2016: Launched in 2011, Juno arrived at Jupiter and began conducting in-depth studies of the planet's atmosphere, deep structure and magnetosphere to unravel its origins and evolution.

Pop culture

Jupiter's sheer size is matched by its significant presence in pop culture, including films, television shows, video games and comic books. Gas giant became a prominent feature in the Wachowski sisters' sci-fi film Jupiter Ascending, various moons of the planet became the home of Cloud Atlas, Futurama, Halo and many other films. In the movie Men in Black, when Agent Jay (Will Smith) said that one of his teachers seemed to be from Venus, Agent Kay (Tommy Lee Jones) replied that she was actually from one of the moons of Jupiter.

The sky above is the most ancient geometry textbook. The first concepts, such as point and circle, come from there. More likely not even a textbook, but a problem book. In which there is no page with answers. Two circles of the same size - the Sun and the Moon - move across the sky, each at its own speed. The remaining objects - luminous points - move all together, as if they are attached to a sphere rotating at a speed of 1 revolution per 24 hours. True, there are exceptions among them - 5 points move as they please. A special word was chosen for them - “planet”, in Greek - “tramp”. As long as humanity has existed, it has been trying to unravel the laws of this perpetual motion. The first breakthrough occurred in the 3rd century BC, when Greek scientists, using the young science of geometry, were able to obtain the first results about the structure of the Universe. This is what we will talk about.

To have some idea of the complexity of the problem, consider this example. Let's imagine a luminous ball with a diameter of 10 cm, hanging motionless in space. Let's call him S. A small ball revolves around it at a distance of just over 10 meters Z with a diameter of 1 millimeter, and around Z at a distance of 6 cm a very tiny ball turns L, its diameter is a quarter of a millimeter. On the surface of the middle ball Z microscopic creatures live. They have some intelligence, but they cannot leave the confines of their ball. All they can do is look at the other two balls - S And L. The question is, can they find out the diameters of these balls and measure the distances to them? No matter how much you think, the matter seems hopeless. We drew a greatly reduced model of the solar system ( S- Sun, Z- Earth, L- Moon).

This was the task that ancient astronomers faced. And they solved it! More than 22 centuries ago, without using anything other than the most elementary geometry - at the 8th grade level (properties of a straight line and a circle, similar triangles and the Pythagorean theorem). And, of course, watching the Moon and the Sun.

Several scientists worked on the solution. We'll highlight two. These are the mathematician Eratosthenes, who measured the radius of the globe, and the astronomer Aristarchus, who calculated the sizes of the Moon, the Sun and the distance to them. How did they do it?

How the globe was measured

People have known for a long time that the Earth is not flat. Ancient navigators observed how the picture of the starry sky gradually changed: new constellations became visible, while others, on the contrary, went beyond the horizon. Ships sailing into the distance “go under water”; the tops of their masts are the last to disappear from view. It is unknown who first expressed the idea that the Earth is spherical. Most likely - the Pythagoreans, who considered the ball to be the most perfect of figures. A century and a half later, Aristotle provides several proofs that the Earth is a sphere. The main one is: during a lunar eclipse, the shadow of the Earth is clearly visible on the surface of the Moon, and this shadow is round! Since then, constant attempts have been made to measure the radius of the globe. Two simple ways are presented in exercises 1 and 2. The measurements, however, turned out to be inaccurate. Aristotle, for example, was mistaken by more than one and a half times. It is believed that the first person to do this with high accuracy was the Greek mathematician Eratosthenes of Cyrene (276–194 BC). His name is now known to everyone thanks to the sieve of Eratosthenes - way to find prime numbers(Fig. 1).

If you cross out one from the natural series, then cross out all the even numbers except the first (the number 2 itself), then all the numbers that are multiples of three, except the first of them (the number 3), etc., then the result will be only prime numbers . Among his contemporaries, Eratosthenes was famous as a major encyclopedist who studied not only mathematics, but also geography, cartography and astronomy. For a long time he headed the Library of Alexandria, the center of world science at that time. While working on compiling the first atlas of the Earth (we were, of course, talking about the part of it known by that time), he decided to make an accurate measurement of the globe. The idea was this. In Alexandria, everyone knew that in the south, in the city of Siena (modern Aswan), one day a year, at noon, the Sun reaches its zenith. The shadow from the vertical pole disappears, and the bottom of the well is illuminated for a few minutes. This happens on the day of the summer solstice, June 22 - the day highest position Sun in the sky. Eratosthenes sends his assistants to Syene, and they establish that at exactly noon (according to the sundial) the Sun is exactly at its zenith. At the same time (as it is written in the original source: “at the same hour”), i.e. at noon according to the sundial, Eratosthenes measures the length of the shadow from a vertical pole in Alexandria. The result is a triangle ABC (AC- pole, AB- shadow, rice. 2).

So, a ray of sunshine in Siena ( N) is perpendicular to the surface of the Earth, which means it passes through its center - the point Z. A beam parallel to it in Alexandria ( A) makes an angle γ = ACB with vertical. Using the equality of crosswise angles for parallel angles, we conclude that AZN= γ. If we denote by l circumference, and through X the length of its arc AN, then we get the proportion . Angle γ in a triangle ABC Eratosthenes measured it and it turned out to be 7.2°. Magnitude X - nothing less than the length of the route from Alexandria to Siena, approximately 800 km. Eratosthenes carefully calculates it based on the average travel time of camel caravans that regularly traveled between the two cities, as well as using data bematists - people of a special profession who measured distances in steps. Now it remains to solve the proportion, obtaining the circumference (i.e. the length of the earth's meridian) l= 40000 km. Then the radius of the Earth R equals l/(2π), this is approximately 6400 km. The fact that the length of the earth's meridian is expressed in such a round number of 40,000 km is not surprising if we remember that the unit of length of 1 meter was introduced (in France in late XVIII century) as one forty millionth of the Earth's circumference (by definition!). Eratosthenes, of course, used a different unit of measurement - stages(about 200 m). There were several stages: Egyptian, Greek, Babylonian, and which of them Eratosthenes used is unknown. Therefore, it is difficult to judge for sure the accuracy of its measurement. In addition, the inevitable error arose due to geographical location two cities. Eratosthenes reasoned this way: if cities are on the same meridian (i.e. Alexandria is located exactly north of Syene), then noon occurs in them at the same time. Therefore, by taking measurements during the highest position of the Sun in each city, we should get the correct result. But in fact, Alexandria and Siena are far from being on the same meridian. Now it’s easy to verify this by looking at the map, but Eratosthenes did not have such an opportunity; he was just working on drawing up the first maps. Therefore, his method (absolutely correct!) led to an error in determining the radius of the Earth. However, many researchers are confident that the accuracy of Eratosthenes' measurements was high and that he was off by less than 2%. Humanity was able to improve this result only 2 thousand years later, in the middle of the 19th century. A group of scientists in France and the expedition of V. Ya. Struve in Russia worked on this. Even in the era of the great geographical discoveries, in the 16th century, people were unable to achieve the result of Eratosthenes and used the incorrect value of the earth's circumference of 37,000 km. Neither Columbus nor Magellan knew the true size of the Earth and what distances they would have to travel. They believed that the length of the equator was 3 thousand km less than it actually was. If they had known, maybe they wouldn’t have sailed.

What is the reason for such a high accuracy of Eratosthenes’ method (of course, if he used the right stage)? Before him, measurements were local, on distances visible to the human eye, i.e. no more than 100 km. These are, for example, the methods in exercises 1 and 2. In this case, errors are inevitable due to the terrain, atmospheric phenomena, etc. To achieve greater accuracy, you need to take measurements globally, at distances comparable to the radius of the Earth. The distance of 800 km between Alexandria and Siena turned out to be quite sufficient.

Exercises
1. How to calculate the radius of the Earth using the following data: from a mountain 500 m high, one can see surroundings at a distance of 80 km?
2. How to calculate the radius of the Earth from the following data: a ship 20 m high, sailing 16 km from the coast, completely disappears from view?
3. Two friends - one in Moscow, the other in Tula, each take a meter-long pole and place them vertically. At the moment during the day when the shadow from the pole reaches its shortest length, each of them measures the length of the shadow. It worked in Moscow A cm, and in Tula - b cm Express the radius of the Earth in terms of A And b. The cities are located on the same meridian at a distance of 185 km.

As can be seen from Exercise 3, Eratosthenes’ experiment can also be done in our latitudes, where the Sun is never at its zenith. True, for this you need two points on the same meridian. If we repeat the experiment of Eratosthenes for Alexandria and Syene, and at the same time make measurements in these cities at the same time (now there are technical possibilities for this), then we will get the correct answer, and it will not matter on which meridian Syene is located (why?).

How the Moon and the Sun were measured. Three steps of Aristarchus

The Greek island of Samos in the Aegean Sea is now a remote province. Forty kilometers long, eight kilometers wide. On this tiny island in different time three greatest geniuses were born - the mathematician Pythagoras, the philosopher Epicurus and the astronomer Aristarchus. Little is known about the life of Aristarchus of Samos. Dates of life are approximate: born around 310 BC, died around 230 BC. We don’t know what he looked like; not a single image has survived (the modern monument to Aristarchus in the Greek city of Thessaloniki is just a sculptor’s fantasy). He spent many years in Alexandria, where he worked in the library and observatory. His main achievement - the book “On the magnitudes and distances of the Sun and Moon” - according to the unanimous opinion of historians, is a real scientific feat. In it, he calculates the radius of the Sun, the radius of the Moon and the distances from the Earth to the Moon and to the Sun. He did it alone, using very simple geometry and everything known results observations of the Sun and Moon. Aristarchus does not stop there; he makes several important conclusions about the structure of the Universe, which were far ahead of their time. It is no coincidence that he was later called “Copernicus of antiquity.”

Aristarchus' calculation can be roughly divided into three steps. Every step comes down to a simple geometric problem. The first two steps are quite elementary, the third is a little more difficult. In geometric constructions we will denote by Z, S And L the centers of the Earth, Sun and Moon respectively, and through R, R s And R l- their radii. We will consider all celestial bodies as spheres, and their orbits as circles, as Aristarchus himself believed (although, as we now know, this is not entirely true). We start with the first step, and for this we will observe the Moon a little.

Step 1. How many times further is the Sun than the Moon?

As you know, the Moon shines by reflected sunlight. If you take a ball and shine a large spotlight on it from the side, then in any position exactly half of the surface of the ball will be illuminated. The boundary of an illuminated hemisphere is a circle lying in a plane perpendicular to the rays of light. Thus, the Sun always illuminates exactly half of the Moon's surface. The shape of the Moon we see depends on how this illuminated half is positioned. At new moon when the Moon is not visible at all in the sky, the Sun illuminates it reverse side. Then the illuminated hemisphere gradually turns towards the Earth. We begin to see a thin crescent, then a month (“waxing Moon”), then a semicircle (this phase of the Moon is called “quadrature”). Then, day by day (or rather, night by night), the semicircle grows to full moon. Then the reverse process begins: the illuminated hemisphere turns away from us. The moon “grows old”, gradually turning into a month, with its left side turned towards us, like the letter “C”, and finally disappears on the night of the new moon. The period from one new moon to the next lasts approximately four weeks. During this time, the Moon makes a full revolution around the Earth. A quarter of the period passes from new moon to half moon, hence the name “quadrature”.

Aristarchus' remarkable guess was that with quadrature, the sun's rays illuminating half of the Moon are perpendicular to the straight line connecting the Moon with the Earth. Thus, in a triangle ZLS apex angle L- straight (Fig. 3). If we now measure the angle LZS, denote it by α, we get that = cos α. For simplicity, we assume that the observer is at the center of the Earth. This will not greatly affect the result, since the distances from the Earth to the Moon and to the Sun significantly exceed the radius of the Earth. So, having measured the angle α between the rays ZL And ZS During the quadrature, Aristarchus calculates the ratio of the distances to the Moon and the Sun. How to catch the Sun and Moon in the sky at the same time? This can be done early in the morning. Difficulty arises for another, unexpected reason. In the time of Aristarchus there were no cosines. The first concepts of trigonometry appear later, in the works of Apollonius and Archimedes. But Aristarchus knew what such triangles were, and that was enough. Drawing a small right triangle Z"L"S" with the same acute angle α = L"Z"S" and measuring its sides, we find that , and this ratio is approximately equal to 1/400.

Step 2. How many times is the Sun larger than the Moon?

In order to find the ratio of the radii of the Sun and the Moon, Aristarchus uses solar eclipses (Fig. 4). They occur when the Moon blocks the Sun. With partial, or, as astronomers say, private During an eclipse, the Moon only passes across the disk of the Sun, without covering it completely. Sometimes such an eclipse cannot even be seen with the naked eye; the Sun shines as on an ordinary day. Only through strong darkness, for example, smoked glass, can one see how part of the solar disk is covered with a black circle. Much less common is a total eclipse, when the Moon completely covers the solar disk for several minutes.

At this time it becomes dark, stars appear in the sky. Eclipses terrified ancient people and were considered harbingers of tragedies. A solar eclipse is observed differently in different parts of the Earth. During a total eclipse, a shadow from the Moon appears on the surface of the Earth - a circle whose diameter does not exceed 270 km. Only in those areas of the globe through which this shadow passes can a total eclipse be observed. Therefore, a total eclipse occurs extremely rarely in the same place - on average once every 200–300 years. Aristarchus was lucky - he was able to observe a total solar eclipse with his own eyes. In the cloudless sky, the Sun gradually began to dim and decrease in size, and twilight set in. For a few moments the Sun disappeared. Then the first ray of light appeared, the solar disk began to grow, and soon the Sun shone in full force. Why does an eclipse last such a short time? Aristarchus answers: the reason is that the Moon has the same apparent dimensions in the sky as the Sun. What does it mean? Let's draw a plane through the centers of the Earth, Sun and Moon. The resulting cross-section is shown in Figure 5 a. Angle between tangents drawn from a point Z to the circumference of the Moon is called angular size Moon, or her angular diameter. The angular size of the Sun is also determined. If the angular diameters of the Sun and Moon coincide, then they have the same apparent sizes in the sky, and during an eclipse, the Moon actually completely blocks the Sun (Fig. 5 b), but only for a moment, when the rays coincide ZL And ZS. The photo shows the full solar eclipse(see Fig. 4) the equality of dimensions is clearly visible.

Aristarchus' conclusion turned out to be amazingly accurate! In reality, the average angular diameters of the Sun and Moon differ by only 1.5%. We are forced to talk about average diameters because they change throughout the year, since the planets do not move in circles, but in ellipses.

Connecting the center of the earth Z with the centers of the Sun S and the moon L, as well as with touch points R And Q, we get two right triangle ZSP And ZLQ(see Fig. 5 a). They are similar because they have a pair of equals sharp cornersβ/2. Hence, . Thus, ratio of the radii of the Sun and Moon equal to the ratio of the distances from their centers to the center of the Earth. So, R s/R l= κ = 400. Despite the fact that their apparent sizes are equal, the Sun turned out to be 400 times larger than the Moon!

The equality of the angular sizes of the Moon and the Sun is a happy coincidence. It does not follow from the laws of mechanics. Many planets in the Solar System have satellites: Mars has two, Jupiter has four (and several dozen more small ones), and they all have different angular dimensions, not coinciding with the solar one.

Now we come to the decisive and most difficult step.

Step 3. Calculate the sizes of the Sun and Moon and their distances

So, we know the ratio of the sizes of the Sun and the Moon and the ratio of their distances to the Earth. This information relative: it restores the picture of the surrounding world only to the point of similarity. You can remove the Moon and Sun from the Earth 10 times, increasing their sizes by the same amount, and the picture visible from the Earth will remain the same. To find actual sizes celestial bodies, we need to correlate them with some known size. But of all the astronomical quantities, Aristarchus still only knows the radius of the globe R= 6400 km. Will this help? Does the radius of the Earth appear in any of the visible phenomena occurring in the sky? It is no coincidence that they say “heaven and earth”, meaning two incompatible things. And yet such a phenomenon exists. This is a lunar eclipse. With his help, using a rather ingenious geometric construction, Aristarchus calculates the ratio of the radius of the Sun to the radius of the Earth, and the circuit is closed: now we simultaneously find the radius of the Moon, the radius of the Sun, and at the same time the distances from the Moon and from the Sun to the Earth.

At lunar eclipse The Moon goes into the Earth's shadow. Hiding behind the Earth, the Moon is deprived sunlight, and thus stops shining. It does not disappear from view completely, since a small part of sunlight is scattered by the earth's atmosphere and reaches the Moon, bypassing the Earth. The moon darkens, acquiring a reddish tint (red and orange rays pass through the atmosphere best). In this case, the shadow of the Earth is clearly visible on the lunar disk (Fig. 6). The round shape of the shadow once again confirms the sphericity of the Earth. Aristarchus was interested in the size of this shadow. In order to determine the radius of the circle of the earth's shadow (we will do this from the photograph in Figure 6), it is enough to solve a simple exercise.

Exercise 4. An arc of a circle is given on a plane. Using a compass and ruler, construct a segment equal to its radius.

Having completed the construction, we find that the radius of the earth's shadow is approximately times larger than the radius of the Moon. Let us now turn to Figure 7. The area of the earth's shadow into which the Moon falls during an eclipse is shaded in gray. Let us assume that the centers of the circles S, Z And L lie on the same straight line. Let's draw the diameter of the Moon M 1 M 2, perpendicular to the line L.S. The extension of this diameter intersects the common tangents of the circles of the Sun and Earth at points D 1 and D 2. Then the segment D 1 D 2 is approximately equal to the diameter of the Earth's shadow. We have arrived at the next problem.

Task 1. Given three circles with centers S, Z And L, lying on the same straight line. Line segment D 1 D 2 passing through L, perpendicular to the line SL, and its ends lie on common external tangents to the first and second circles. It is known that the ratio of the segment D 1 D 2 to the diameter of the third circle is equal to t, and the ratio of the diameters of the first and third circles is equal to ZS/ZL= κ. Find the ratio of the diameters of the first and second circles.

If you solve this problem, you will find the ratio of the radii of the Sun and the Earth. This means that the radius of the Sun will be found, and with it the Moon. But it will not be possible to solve it. You can try - the problem is missing one datum. For example, the angle between common external tangents to the first two circles. But even if this angle were known, the solution would use trigonometry, which Aristarchus did not know (we formulate the corresponding problem in Exercise 6). He finds an easier way out. Let's draw the diameter A 1 A 2 first circles and diameter B 1 B 2 second, both are parallel to the segment D 1 D 2 . Let C 1 and WITH 2 - intersection points of the segment D 1 D 2 with straight lines A 1 B 1 And A 2 IN 2 accordingly (Fig. 8). Then, as the diameter of the earth’s shadow, we take the segment C 1 C 2 instead of a segment D 1 D 2. Stop, stop! What does it mean, “take one segment instead of another”? They are not equal! Line segment C 1 C 2 lies inside the segment D 1 D 2 means C 1 C 2 <D 1 D 2. Yes, the segments are different, but they almost equal. The fact is that the distance from the Earth to the Sun is many times greater than the diameter of the Sun (about 215 times). Therefore the distance ZS between the centers of the first and second circles significantly exceeds their diameters. This means that the angle between the common external tangents to these circles is close to zero (in reality it is approximately 0.5°), i.e. the tangents are “almost parallel”. If they were exactly parallel, then the points A 1 and B 1 would coincide with the points of contact, therefore, the point C 1 would match D 1 , a C 2 s D 2, which means C 1 C 2 =D 1 D 2. Thus, the segments C 1 C 2 and D 1 D 2 are almost equal. Aristarchus’ intuition did not fail here either: in fact, the difference between the lengths of the segments is less than a hundredth of a percent! This is nothing compared to possible measurement errors. Having now removed the extra lines, including circles and their common tangents, we arrive at the following problem.

Task 1". On the sides of the trapezoid A 1 A 2 WITH 2 WITH 1 points taken B 1 and IN 2 so that the segment IN 1 IN 2 is parallel to the bases. Let S, Z u L- midpoints of segments A 1 A 2 , B 1 B 2 and C 1 C 2 respectively. Based C 1 C 2 lies the segment M 1 M 2 with middle L. It is known that And . Find A 1 A 2 /B 1 B 2 .

Solution. Since , then , and therefore triangles A 2 SZ And M 1 LZ similar with coefficient SZ/LZ= κ. Hence, A 2 SZ= M 1 LZ, and therefore the point Z lies on the segment M 1 A 2 . Likewise, Z lies on the segment M 2 A 1 (Fig. 9). Because C 1 C 2 = t·M 1 M 2 And , That .

Hence,

On the other side,

Means, . From this equality we immediately obtain that .

So, the ratio of the diameters of the Sun and the Earth is equal, and the ratio of the Moon and the Earth is equal.

Substituting the known values κ = 400 and t= 8/3, we find that the Moon is approximately 3.66 times smaller than the Earth, and the Sun is 109 times larger than the Earth. Since the radius of the Earth R we know, we find the radius of the Moon R l= R/3.66 and the radius of the Sun R s= 109R.

Now the distances from the Earth to the Moon and to the Sun are calculated in one step, this can be done using the angular diameter. The angular diameter β of the Sun and Moon is approximately half a degree (0.53° to be precise). How ancient astronomers measured it will be discussed later. Dropping the tangent ZQ on the circumference of the Moon, we get a right triangle ZLQ with an acute angle β/2 (Fig. 10).

From it we find , which is approximately equal to 215 R l, or 62 R. Likewise, the distance to the Sun is 215 R s = 23 455R.

All. The sizes of the Sun and Moon and the distances to them have been found.

Exercises
5. Prove that straight lines A 1 B 1 , A 2 B 2 and two common external tangents to the first and second circles (see Fig. 8) intersect at one point.
6. Solve Problem 1 if you additionally know the angle between the tangents between the first and second circles.
7. A solar eclipse may be observed in some parts of the globe and not in others. What about a lunar eclipse?
8. Prove that a solar eclipse can only be observed during a new moon, and a lunar eclipse can only be observed during a full moon.
9. What happens on the Moon when there is a lunar eclipse on Earth?

About the benefits of mistakes

In fact, everything was somewhat more complicated. Geometry was just being formed, and many things that were familiar to us since the eighth grade of school were not at all obvious at that time. It took Aristarchus to write a whole book to convey what we have outlined in three pages. And with experimental measurements, everything was also not easy. Firstly, Aristarchus made a mistake in measuring the diameter of the earth's shadow during a lunar eclipse, obtaining the ratio t= 2 instead of . In addition, he seemed to proceed from the wrong value of the angle β - the angular diameter of the Sun, considering it equal to 2°. But this version is controversial: Archimedes in his treatise “Psammit” writes that, on the contrary, Aristarchus used an almost correct value of 0.5°. However, the most terrible error occurred at the first step, when calculating the parameter κ - the ratio of the distances from the Earth to the Sun and to the Moon. Instead of κ = 400, Aristarchus got κ = 19. How could it be more than 20 times wrong? Let us turn again to step 1, Figure 3. In order to find the ratio κ = ZS/ZL, Aristarchus measured the angle α = SZL, and then κ = 1/cos α. For example, if the angle α were 60°, then we would get κ = 2, and the Sun would be twice as far from the Earth as the Moon. But the measurement result was unexpected: the angle α turned out to be almost straight. This meant that the leg ZS many times superior ZL. Aristarchus got α = 87°, and then cos α =1/19 (remember that all our calculations are approximate). The true value of the angle is , and cos α =1/400. So a measurement error of less than 3° led to an error of 20 times! Having completed the calculations, Aristarchus comes to the conclusion that the radius of the Sun is 6.5 radii of the Earth (instead of 109).

Errors were inevitable, given the imperfect measuring instruments of the time. The more important thing is that the method turned out to be correct. Soon (by historical standards, i.e. after about 100 years), the outstanding astronomer of antiquity Hipparchus (190 - ca. 120 BC) will eliminate all the inaccuracies and, following the method of Aristarchus, calculate the correct sizes of the Sun and Moon. Perhaps Aristarchus' mistake turned out to be useful in the end. Before him, the prevailing opinion was that the Sun and Moon either had the same dimensions (as it seems to an earthly observer), or differed only slightly. Even the 19-fold difference surprised contemporaries. Therefore, it is possible that if Aristarchus had found the correct ratio κ = 400, no one would have believed it, and perhaps the scientist himself would have abandoned his method, considering the result absurd. A well-known principle states that geometry is the art of reasoning well from poorly executed drawings. To paraphrase, we can say that science in general is the art of drawing correct conclusions from inaccurate, or even erroneous, observations. And Aristarchus made this conclusion. 17 centuries before Copernicus, he realized that at the center of the world is not the Earth, but the Sun. This is how the heliocentric model and the concept of the solar system first appeared.

What's in the center?

The prevailing idea in the Ancient World about the structure of the Universe, familiar to us from history lessons, was that in the center of the world there was a stationary Earth, with 7 planets revolving around it in circular orbits, including the Moon and the Sun (which was also considered a planet). Everything ends with a celestial sphere with stars attached to it. The sphere revolves around the Earth, making a full revolution in 24 hours. Over time, corrections were made to this model many times. Thus, they began to believe that the celestial sphere is motionless, and the Earth rotates around its axis. Then they began to correct the trajectories of the planets: the circles were replaced with cycloids, i.e., lines that describe the points of a circle as it moves along another circle (you can read about these wonderful lines in the books of G. N. Berman “Cycloid”, A. I. Markushevich “Remarkable curves”, as well as in “Quantum”: article by S. Verov “Secrets of the Cycloid” No. 8, 1975, and article by S. G. Gindikin “Stellar Age of the Cycloid”, No. 6, 1985). Cycloids were in better agreement with the results of observations, in particular, they explained the “retrograde” movements of the planets. This - geocentric system of the world, at the center of which is the Earth (“gaia”). In the 2nd century, it took its final form in the book “Almagest” by Claudius Ptolemy (87–165), an outstanding Greek astronomer, namesake of the Egyptian kings. Over time, some cycloids became more complex, and more and more intermediate circles were added. But in general, the Ptolemaic system dominated for about one and a half millennia, until the 16th century, before the discoveries of Copernicus and Kepler. At first, Aristarchus also adhered to the geocentric model. However, having calculated that the radius of the Sun is 6.5 times the radius of the Earth, he asked a simple question: why should such a large Sun revolve around such a small Earth? After all, if the radius of the Sun is 6.5 times greater, then its volume is almost 275 times greater! This means that the Sun must be in the center of the world. 6 planets revolve around it, including Earth. And the seventh planet, the Moon, revolves around the Earth. This is how it appeared heliocentric world system (“helios” - the Sun). Aristarchus himself noted that such a model better explains the apparent motion of planets in circular orbits and is in better agreement with observational results. But neither scientists nor official authorities accepted it. Aristarchus was accused of atheism and was persecuted. Of all the astronomers of antiquity, only Seleucus became a supporter of the new model. No one else accepted it, at least historians have no firm information on this matter. Even Archimedes and Hipparchus, who revered Aristarchus and developed many of his ideas, did not dare to place the Sun at the center of the world. Why?

Why didn't the world accept the heliocentric system?

How did it happen that for 17 centuries scientists did not accept the simple and logical system of the world proposed by Aristarchus? And this despite the fact that the officially recognized geocentric system of Ptolemy often failed, not consistent with the results of observations of the planets and stars. We had to add more and more new circles (the so-called nested loops) for the “correct” description of the motion of the planets. Ptolemy himself was not afraid of difficulties; he wrote: “Why be surprised at the complex movement of celestial bodies if their essence is unknown to us?” However, by the 13th century, 75 of these circles had accumulated! The model became so cumbersome that cautious objections began to be heard: is the world really that complicated? A widely known case is that of Alfonso X (1226–1284), king of Castile and Leon, a state that occupied part of modern Spain. He, the patron of sciences and arts, who gathered fifty of the best astronomers in the world at his court, said at one of the scientific conversations that “if, at the creation of the world, the Lord had honored me and asked my advice, many things would have been arranged more simply.” Such insolence was not forgiven even to kings: Alphonse was deposed and sent to a monastery. But doubts remained. Some of them could be resolved by placing the Sun at the center of the Universe and adopting the Aristarchus system. His works were well known. However, for many centuries, none of the scientists dared to take such a step. The reasons were not only fear of the authorities and the official church, which considered Ptolemy’s theory to be the only correct one. And not only in the inertia of human thinking: it is not so easy to admit that our Earth is not the center of the world, but just an ordinary planet. Still, for a real scientist, neither fear nor stereotypes are obstacles on the path to the truth. The heliocentric system was rejected for completely scientific, one might even say geometric, reasons. If we assume that the Earth rotates around the Sun, then its trajectory is a circle with a radius equal to the distance from the Earth to the Sun. As we know, this distance is equal to 23,455 Earth radii, i.e. more than 150 million kilometers. This means that the Earth moves 300 million kilometers within six months. Gigantic size! But the picture of the starry sky for an earthly observer remains the same. The Earth alternately approaches and moves away from the stars by 300 million kilometers, but neither the apparent distances between the stars (for example, the shape of the constellations) nor their brightness change. This means that the distances to the stars should be several thousand times greater, i.e. the celestial sphere should have completely unimaginable dimensions! This, by the way, was realized by Aristarchus himself, who wrote in his book: “The volume of the sphere of fixed stars is as many times greater than the volume of a sphere with the radius of the Earth-Sun, how many times the volume of the latter is greater than the volume of the globe,” i.e., according to Aristarchus it turned out that the distance to the stars was (23,455) 2 R, that's more than 3.5 trillion kilometers. In reality, the distance from the Sun to the nearest star is still about 11 times greater. (In the model we presented at the very beginning, when the distance from the Earth to the Sun is 10 m, the distance to the nearest star is ... 2700 kilometers!) Instead of a compact and cozy world, in which the Earth is at the center and which fits inside a relatively small celestial sphere, Aristarchus drew an abyss. And this abyss scared everyone.

Venus, Mercury and the impossibility of a geocentric system

Meanwhile, the impossibility of a geocentric system of the world, with the circular motions of all planets around the Earth, can be established using a simple geometric problem.

Task 2. A plane is given two circles with a common center ABOUT, two points move uniformly along them: a point M along one circle and a point V on the other. Prove that either they move in the same direction with the same angular velocity, or at some point in time the angle MOV blunt.

Solution. If the points move in the same direction at different speeds, then after some time the rays OM And O.V. will be co-directed. Next angle MOV begins to increase monotonically until the next coincidence, i.e., up to 360°. Therefore, at some moment it is equal to 180°. The case when the points move in different directions is considered in the same way.

Theorem. A situation in which all the planets of the Solar System rotate uniformly around the Earth in circular orbits is impossible.

Proof. Let ABOUT- the center of the Earth, M- the center of Mercury, and V- center of Venus. According to long-term observations, Mercury and Venus have different orbital periods, and the angle MOV never exceeds 76°. By virtue of the result of Problem 2, the theorem is proven.

Of course, the ancient Greeks repeatedly encountered similar paradoxes. That is why, in order to save the geocentric model of the world, they forced the planets to move not in circles, but in cycloids.

The proof of the theorem is not entirely fair, since Mercury and Venus do not rotate in the same plane, as in problem 2, but in different ones. Although the planes of their orbits almost coincide: the angle between them is only a few degrees. In Exercise 10, we invite you to eliminate this drawback and solve an analogue of Problem 2 for points rotating in different planes. Another objection: maybe the angle MOV can be stupid, but we don’t see it because it’s daytime on Earth at that time? We accept this too. In Exercise 11 you need to prove that for three rotating radii, there will always come a point in time when they form obtuse angles with each other. If at the ends of the radii there are Mercury, Venus and the Sun, then at this moment in time Mercury and Venus will be visible in the sky, but the Sun will not, i.e. it will be night on earth. But we must warn you: exercises 10 and 11 are much more difficult than problem 2. Finally, in exercise 12 we ask you, no less, to calculate the distance from Venus to the Sun and from Mercury to the Sun (they, of course, revolve around the Sun, not around Earth). See for yourself how simple it is after we have learned Aristarchus' method.

Exercises
10. Two circles with a common center are given in space ABOUT, two points move along them uniformly with different angular velocities: point M along one circle and a point V on the other. Prove that at some moment the angle MOV blunt.
11. Three circles with a common center are given on a plane ABOUT, three points move uniformly along them with different angular velocities. Prove that at some moment all three angles between the rays with the vertex ABOUT, directed to these points, are obtuse.
12. It is known that the maximum angular distance between Venus and the Sun, i.e. the maximum angle between the rays directed from the Earth to the centers of Venus and the Sun, is 48°. Find the radius of Venus's orbit. The same applies to Mercury, if it is known that the maximum angular distance between Mercury and the Sun is 28°.

The final touch: measuring the angular sizes of the Sun and Moon

Following Aristarchus' reasoning step by step, we missed only one aspect: how was the angular diameter of the Sun measured? Aristarchus himself did not do this, using the measurements of other astronomers (apparently not entirely correct). Let us recall that he was able to calculate the radii of the Sun and Moon without using their angular diameters. Look again at steps 1, 2 and 3: nowhere is the angular diameter value used! It is only needed to calculate the distances to the Sun and the Moon. Trying to determine the angular size “by eye” does not bring success. If you ask several people to estimate the angular diameter of the Moon, most will name the angle from 3 to 5 degrees, which is many times larger than the true value. This is an optical illusion: the bright white Moon appears massive against the dark sky. The first to carry out a mathematically rigorous measurement of the angular diameter of the Sun and Moon was Archimedes (287-212 BC). He outlined his method in the book “Psammit” (“Calculation of grains of sand”). He was aware of the complexity of the task: “Obtaining the exact value of this angle is not an easy task, because neither the eye, nor the hands, nor the instruments with which the reading is made provide sufficient accuracy.” Therefore, Archimedes does not undertake to calculate the exact value of the angular diameter of the Sun, he only estimates it from above and below. He places a round cylinder at the end of a long ruler, opposite the observer's eye. The ruler is directed towards the Sun, and the cylinder is moved towards the eye until it completely obscures the Sun. Then the observer leaves, and a segment is marked at the end of the ruler MN, equal to the size of the human pupil (Fig. 11).

Then the angle α 1 between the lines MR And NQ less than the angular diameter of the Sun, and angle α 2 = P.O.Q.- more. We designated by PQ the diameter of the base of the cylinder, and through O - the middle of the segment MN. So α 1< β < α 2 (докажите это в упражнении 13). Так Архимед находит, что угловой диаметр Солнца заключен в пределах от 0,45° до 0,55°.

It remains unclear why Archimedes measured the Sun and not the Moon. He was well acquainted with the book of Aristarchus and knew that the angular diameters of the Sun and Moon are the same. It is much more convenient to measure the moon: it does not blind the eyes and its boundaries are more clearly visible.

Some ancient astronomers measured the angular diameter of the Sun based on the duration of a solar or lunar eclipse. (Try to restore this method in Exercise 14.) Or you can do the same without waiting for eclipses, but simply watching the sunset. Let's choose for this the day of the vernal equinox, March 22, when the Sun rises exactly in the east and sets exactly in the west. This means that the sunrise points E and sunset W diametrically opposed. For an observer on earth, the Sun moves in a circle with a diameter E.W.. The plane of this circle makes an angle of 90° with the horizon plane – γ, where γ is the geographic latitude of the point M, in which the observer is located (for example, for Moscow γ = 55.5°, for Alexandria γ = 31°). The proof is given in Figure 12. Direct ZP- the axis of rotation of the Earth, perpendicular to the plane of the equator. Point latitude M- angle between segment ZP and the plane of the equator. Let's pass through the center of the Sun S plane α perpendicular to the axis ZP.

The horizon plane touches the globe at a point M. For an observer located at a point M, The Sun moves in a circle during the day in the α plane with the center R and radius PS. The angle between the plane α and the horizontal plane is equal to the angle MZP, which is equal to 90° – γ, since the plane α is perpendicular ZP, and the horizon plane is perpendicular ZM. So, on the day of the equinox, the Sun sets below the horizon at an angle of 90° - γ. Consequently, during sunset it passes an arc of a circle equal to β/cos γ, where β is the angular diameter of the Sun (Fig. 13). On the other hand, in 24 hours it travels a full circle around this circle, i.e. 360°.

We get the proportion where it is six, not nine, since Uranus, Neptune and Pluto were discovered much later. Most recently, on September 13, 2006, by decision of the International Astronomical Union (IAU), Pluto lost its planetary status. So there are now eight planets in the solar system.
The real reason for the disgrace of King Alphonse was, apparently, the usual struggle for power, but his ironic remark about the structure of the world served as a good reason for his enemies.

We are accustomed to treating the Sun as a given. It appears every morning to shine throughout the day and then disappear over the horizon until the next morning. This continues from century to century. Some worship the Sun, others do not pay attention to it, since they spend most of their time indoors.

Regardless of how we feel about the Sun, it continues to perform its function - giving light and warmth. Everything has its own size and shape. Thus, the Sun has an almost ideal spherical shape. Its diameter is almost the same throughout its entire circumference. The differences can be on the order of 10 km, which is negligible.

Few people think about how far the star is from us and what size it is. And the numbers can surprise. Thus, the distance from the Earth to the Sun is 149.6 million kilometers. Moreover, each individual ray of sunlight reaches the surface of our planet in 8.31 minutes. It is unlikely that in the near future people will learn to fly at the speed of light. Then it would be possible to get to the surface of the star in more than eight minutes.

Dimensions of the Sun

Everything is relative. If we take our planet and compare it in size with the Sun, it will fit on its surface 109 times. The radius of the star is 695,990 km. Moreover, the mass of the Sun is 333,000 times greater than the mass of the Earth! Moreover, in one second it gives off energy equivalent to 4.26 million tons of mass loss, that is, 3.84x10 to the 26th power of J.

Which earthling can boast that he has walked along the equator of the entire planet? There will probably be travelers who crossed the Earth on ships and other vehicles. This took a lot of time. It would take them much longer to go around the Sun. This will take at least 109 times more effort and years.

The sun can visually change its size. Sometimes it seems several times larger than usual. Other times, on the contrary, it decreases. It all depends on the state of the Earth's atmosphere.

What is the Sun

The sun does not have the same dense mass as most planets. A star can be compared to a spark that constantly releases heat into the surrounding space. In addition, explosions and plasma separations periodically occur on the surface of the Sun, which greatly affects people’s well-being.

The temperature on the surface of the star is 5770 K, in the center - 15,600,000 K. With an age of 4.57 billion years, the Sun is capable of remaining the same bright star for an entire

Its planets and stars, especially compared to our Earth.

British astronomer John Brady(John Brady) tried to clearly show the scale of objects in our galaxy, superimposing the continents of the Earth and our world on the celestial bodies.

Many objects are so large that it is quite difficult to show their actual size.

Sizes of planet Earth in comparison

Neutron star

Neutron star compared to north east England

A neutron star is a rather strange and unusual object. Although it is only 20 kilometers in diameter, it has 1.5 times the mass of the Sun as it is incredibly dense.

So dense that a teaspoon would weigh a billion tons. And if you stood on its surface, you would feel gravity, which is 200 billion times greater than on our planet.

In addition, a neutron star has the ability to rotate, and the speed of the fastest neutron star is 716 times per second.

Mount Olympus on Mars

The Martian volcano Olympus Mounts in Arizona

Although Mars is a relatively small planet, it is home to largest volcano in the solar system- Mount Olympus. It is 3 times higher than Mount Everest, reaching 624 km in width and 26 km high.

At the top of this incredible structure is a caldera with a diameter of 80 km.

Jupiter's moon Io

Comparison of Jupiter's moon Io with North America

Io's satellite is the most volcanic body in the Solar System. Its diameter is 3636 km, and its size is close to the size of the Earth's satellite - the Moon. Io is simply tiny compared to Jupiter, being 350,000 km away (or 2.5 Jupiters).

Due to Jupiter's gravitational pull, Io's core is molten and volcanoes on the surface spew lava, coating Io in yellow sulfur. Lava flows so high that if they took place on Earth, they would be higher than the International Space Station.

Sizes of stars and planets in the solar system

The planet Mars

North America compared to Mars

The planet Mars is not as big as it might seem. If you decided to fly from one side of Mars to the other, it would take 8 hours. The diameter of Mars is 6,792 km at the equator, and from pole to pole it is 40 km smaller.

Mars is the second smallest planet in the solar system after Mercury. In fact The land mass of Mars is almost the same as that of Earth, and although it is much smaller than Earth, it does not have oceans.

Saturn

In the image you can see how much larger Saturn is than Earth.

The width of Saturn's rings would fit 6 planets Earth.

The diameter of the main disk of Saturn could fit almost 10 planets Earth, and if the space inside Saturn could be filled, it would fit 764 Earths.

Rings of Saturn

This is what our planet would look like if Earth were placed instead of Saturn's disk

Saturn's icy rings are made up of billions of particles, ranging from tiny grains to mountain-sized blocks.

The rings reach 1 km thick, and the distance from the inner ring to the outer ring is 282,000 km, and this is three-quarters of the distance from the Earth to the Moon.

Jupiter

The dimensions of North America against the background of Jupiter

Jupiter is the largest planet in the solar system, and its mass is greater than all the planets and moons combined.

Jupiter's diameter is 142,984 km at the equator. This is 11 times the diameter of our planet. Lightning on Jupiter is 1000 times stronger than on Earth, and wind speeds in the upper atmosphere can reach 100 meters per second.

In addition, it is the fastest rotating planet that makes revolution around its axis in 10 hours(The earth rotates around g of its axis in 24 hours).

Sun

Earth compared to the Sun

The sun makes up 99.86 percent of the mass of the entire solar system, which means that our Earth, other planets and satellites are just fine rubble left over from the formation of the Sun 4.5 billion years ago.

An ordinary sunspot easily outshines the Earth in size. The diameter of the Sun can fit 109 planets Earth, and to fill the volume of the Sun would require 1,300,000 Lands.

Upon closer examination, the Sun appears granular, and in total there are up to 4 million such granules across the diameter of the solar disk, each of them up to 1000 km in size.

In 1 second, the Sun releases more energy than has been produced in the entire history of mankind. It loses 4 billion material every second, but it can live another 5 billion years.

But it is worth remembering that the Sun is everything one of the hundreds of billions of stars in our Milky Way galaxy.

Our Solar System consists of the Sun, the planets orbiting it, and smaller celestial bodies. All of these are mysterious and surprising because they are still not fully understood. Below will be indicated the sizes of the planets of the solar system in ascending order, and a brief description of the planets themselves.

There is a well-known list of planets, in which they are listed in order of their distance from the Sun:

Pluto used to be in last place, but in 2006 it lost its status as a planet, as larger celestial bodies were found further away from it. The listed planets are divided into rocky (inner) and giant planets.

Brief information about rocky planets

The inner (rocky) planets include those bodies that are located inside the asteroid belt separating Mars and Jupiter. They got their name “stone” because they consist of various hard rocks, minerals and metals. They are united by a small number or absence of satellites and rings (like Saturn). On the surface of rocky planets there are volcanoes, depressions and craters formed as a result of the fall of other cosmic bodies.

But if you compare their sizes and arrange them in ascending order, the list will look like this:

Brief information about the giant planets

The giant planets are located beyond the asteroid belt and are therefore also called outer planets. They consist of very light gases - hydrogen and helium. These include:

But if you make a list by the size of the planets in the solar system in ascending order, the order changes:

A little information about the planets

In modern scientific understanding, a planet means a celestial body that revolves around the Sun and has sufficient mass for its own gravity. Thus, there are 8 planets in our system, and, importantly, these bodies are not similar to each other: each has its own unique differences, both in appearance and in the components of the planet themselves.

- This is the planet closest to the Sun and the smallest among the others. It weighs 20 times less than the Earth! But, despite this, it has a fairly high density, which allows us to conclude that there are a lot of metals in its depths. Due to its strong proximity to the Sun, Mercury is subject to sudden temperature changes: at night it is very cold, during the day the temperature rises sharply.

- This is the next planet closest to the Sun, in many ways similar to Earth. It has a more powerful atmosphere than Earth, and is considered a very hot planet (its temperature is above 500 C).

- This is a unique planet due to its hydrosphere, and the presence of life on it led to the appearance of oxygen in its atmosphere. Most of the surface is covered with water, and the rest is occupied by continents. A unique feature is the tectonic plates, which move, albeit very slowly, resulting in changes in the landscape. The Earth has one satellite - the Moon.

– also known as the “Red Planet”. It gets its fiery red color from a large amount of iron oxides. Mars has a very thin atmosphere and much lower atmospheric pressure compared to Earth. Mars has two satellites - Deimos and Phobos.

is a real giant among the planets of the solar system. Its weight is 2.5 times the weight of all the planets combined. The surface of the planet consists of helium and hydrogen and is in many ways similar to the sun. Therefore, it is not surprising that there is no life on this planet - there is no water and a solid surface. But Jupiter has a large number of satellites: 67 are currently known.

– This planet is famous for the presence of rings consisting of ice and dust revolving around the planet. With its atmosphere it resembles that of Jupiter, and in size it is slightly smaller than this giant planet. In terms of the number of satellites, Saturn is also slightly behind - it has 62 known. The largest satellite, Titan, is larger than Mercury.

- the lightest planet among the outer ones. Its atmosphere is the coldest in the entire system (minus 224 degrees), it has a magnetosphere and 27 satellites. Uranium consists of hydrogen and helium, and the presence of ammonia ice and methane has also been noted. Because Uranus has a high axial tilt, it appears as if the planet is rolling rather than rotating.

- despite its smaller size than , it is heavier and exceeds the mass of the Earth. This is the only planet that was found through mathematical calculations, and not through astronomical observations. The strongest winds in the solar system were recorded on this planet. Neptune has 14 moons, one of which, Triton, is the only one that rotates in the opposite direction.

It is very difficult to imagine the entire scale of the solar system within the limits of the studied planets. It seems to people that the Earth is a huge planet, and, in comparison with other celestial bodies, it is so. But if you place giant planets next to it, then the Earth already takes on tiny dimensions. Of course, next to the Sun, all celestial bodies appear small, so representing all the planets in their full scale is a difficult task.

The most famous classification of planets is their distance from the Sun. But a listing that takes into account the sizes of the planets of the Solar System in ascending order would also be correct. The list will be presented as follows:

As you can see, the order has not changed much: the inner planets are on the first lines, and Mercury occupies the first place, and the outer planets occupy the remaining positions. In fact, it doesn’t matter at all in what order the planets are located, this will not make them any less mysterious and beautiful.