Lunar eclipse - interesting facts and hypotheses. Interesting information about a lunar eclipse At what lunar phase can the sun be observed?

> Lunar eclipse

What's happened moon eclipse: characteristics of the phenomenon and its essence, formation scheme, calendar of lunar eclipses, total, partial, penumbral with photos, how to observe.

In essence, an eclipse is the complete or partial darkening of one object in the sky by another. Thus, moon eclipse- This is the immersion of the Moon in the cone of the earth's shadow. In this case, our planet is located on the line between the center of the Moon and the center of the Sun. The phenomenon occurs when the brightness of the Moon's disk decreases significantly.

Objects in space move, so the movement of the shadow across the lunar surface creates the phases of the moon during an eclipse. It is customary to distinguish between penumbral (the Moon is immersed only in the Earth's penumbra), partial (at the peak of the eclipse only part of the lunar disk is immersed in the Earth's shadow) and total (the lunar disk completely enters the Earth's shadow) lunar eclipses. That is, by understanding the level of the Moon’s immersion in the Earth’s shadow, you can understand what kind of lunar eclipse you are looking at. Observations of such phenomena can be carried out in any corner of the world where the Moon is located above the horizon. The average duration of an eclipse is several hours.

As stated above, lunar eclipses only occur during the full moon. If we imagine that the Moon revolves around our planet in the same plane in which the Earth revolves around the Sun, then observers could admire lunar eclipses at every full moon. However, the plane of the lunar orbit is at an angle of 5˚ to the plane of the ecliptic, therefore moon eclipse occurs only if the Moon approaches the nodes of its orbit. When the full moon and new moon fall into the zone of the Lunar nodes, lunar and solar eclipses are related.

Lunar eclipse calendar

Lunar eclipse calendar indicates the dates and year of future lunar eclipse events. You can see what the best visibility area on Earth will be, indicating the maximum phase point and area of ​​the lunar eclipse. In addition, you can see the dates of past and future lunar eclipses, where the frequency and interval between eclipses are noticeable.

Lunar eclipse: basic concepts

An incredibly beautiful cosmic phenomenon that is observed by a large number of people, but the description may contain not entirely clear terms and phases familiar to astronomy. Let's study them carefully. Also remember what conditions are needed for a lunar eclipse to occur, when the Blood Moon appears, and how this is affected by the distance of the satellite from the Earth.

Occurs at the moment when the Moon is completely immersed in the shadow space. The total phase of the eclipse lasts up to 1.5 hours, then the edge of the Moon again appears in the field of view.

An eclipse occurs at the moment when the Moon plunges into shadow with only one edge, and part of its surface remains illuminated.

Around the cone of the Earth's shadow there is a space where the Earth only partially obscures the Sun. In the event that the Moon crosses the penumbral region, but does not plunge into the shadow, a penumbral eclipse is observed. At this moment, the Moon's brilliance weakens slightly. It is almost impossible to notice this with the naked eye. And only during the period when the Moon approaches the cone of complete shadow in clear sky conditions can you see a slight darkening from one edge of the Moon.

The moment of greatest eclipse is an event that is characterized by the smallest distance between the axis of the Moon's shadow cone and the center of our planet. The point of greatest eclipse is the area of ​​the earth's surface where the maximum phase of the eclipse can be observed at the moment of greatest eclipse.

The essence of a lunar eclipse

The minimum distance from the surface of our planet to the Moon is about 363 thousand kilometers. Moreover, the size of the shadow that the Earth is capable of creating at such a distance is approximately 2.5 times greater than the diameter of the Moon itself. Therefore, it is able to completely cover the Moon. An eclipse occurs when the Moon enters the Earth's shadow. If the shadow completely covers the lunar disk, a total lunar eclipse occurs. This process is clearly demonstrated by the diagram of a lunar eclipse.

In that part of the earth's surface where the Moon is above the horizon, it is possible to observe a lunar eclipse, and from any point its appearance will be the same. The eclipse is not visible from the rest of the globe. Scientists have calculated that the maximum duration of one total lunar eclipse can be 108 minutes. Eclipses like this don't happen very often. The last long eclipses were observed on August 13, 1859 and July 16, 2000.

The degree of shadow coverage of the lunar surface at each moment in time is called the phase of the lunar eclipse. The zero phase is calculated as the ratio from the center of the Moon to the center of the shadow cast by the Earth. Astronomical values ​​of zero and phase are calculated for each moment of a lunar eclipse.

Cases when the Earth's shadow partially covers the Moon are called partial eclipses. In this case, part of the lunar surface is covered with shadow, and part is illuminated by the sun's rays or remains in partial shade.

The region of space where our planet does not completely block the sun's rays, located along the perimeter of the cone of the cast shadow, is called penumbra. If the Moon does not enter the shadow, but only falls into the penumbra region, then this phenomenon is called a penumbral eclipse. At the same time, the brightness of the Moon decreases slightly, which is almost invisible to the naked eye. Only when the Moon passes near the main cone of total shadow does a slight darkening occur on one side of the lunar disk. You can observe a penumbral eclipse using special devices.

Since at the moment of a total eclipse the Moon is illuminated exclusively by rays passing through the upper layer of the atmosphere, depending on its condition, the lunar disk becomes reddish or brownish in color. The difference in color can be seen by comparing photographs of lunar eclipses from different years.

For example, during the eclipse of July 6, 1982, the Moon had a reddish tint, and during the eclipse of January 06, 2000, it was slightly brownish. There are no blue or green solar eclipses because the Earth's atmosphere tends to scatter red rays to a greater extent.

Total lunar eclipses can differ in both color and brightness. To determine it, a special scale was developed, which was named after the famous French astronomer Andre Danjon. The gradation of this scale has 5 divisions:

• zero division means the darkest eclipse, when the Moon is barely visible in the sky;
• one means a dark gray eclipse, when some details become visible on the lunar surface;
• a two denotes a grayish eclipse with a brownish tint;
• a light reddish-brown eclipse is indicated by a three;
• during the last, brightest fourth type of eclipse, the moon becomes copper-red in color, during which all the main details on the surface of the lunar disk can be seen with the naked eye.

If the Moon’s orbit were in the ecliptic plane, then lunar and solar eclipses would be observed monthly. But, due to the fact that the Moon spends more time above or below the plane of the Earth's orbit, it falls into shadow only twice a year. The angle of inclination of the plane of the lunar orbit relative to the orbit of our planet is 5 degrees. Therefore, at moments when the Moon is located in a straight line between the Earth and the Sun, an eclipse occurs. During the new moon, the Moon blocks the sunlight, and during the full moon, it falls into the shadow of the Earth.

It happens that the gap between solar and lunar eclipses is small. There can be at least 2 lunar eclipses every year. Due to the fact that the lunar and earth's orbits are in different planes, the phases of eclipses may differ. Moreover, eclipses of the same phase are repeated with a certain periodicity. This period is called saros and is 6585⅓ days (18 years 11 days and 8 hours). Thus, knowing the time of the previous eclipse, you can determine with an accuracy of up to a minute when exactly the same next eclipse will occur in a particular area.

Such cyclicity is often used to determine the date and time of certain historical events described in old sources. The first total eclipse was described in ancient Chinese chronicles. After making certain calculations, scientists were able to find out that it dates back to January 29, 1136 BC. Information about three more eclipses is contained in the Almagest of Claudius Ptolemy and dates back to 04/19/721 BC, 04/08/720 AD. and 01.09.720 BC.

Lunar eclipses are mentioned quite often in historical chronicles. For example, the famous Athenian military leader Nicias was frightened by a lunar eclipse, panic began in his army, because of which the Athenians were defeated. After carrying out certain calculations, it was possible to establish the exact date of this event (08/27/413 BC).

A fairly well-known historical fact is the total lunar eclipse of 1504, which came to the aid of the expedition of Christopher Columbus. At that time they were in Jamaica and experienced difficulties with food and drinking water. Attempts to obtain provisions from the local Indians were unsuccessful. But Columbus knew for sure that a lunar eclipse would occur on the night of March 1st. He warned the leaders that if they did not deign to deliver drinking water and food to the travelers’ ship, he would steal the Moon from the sky. With the onset of darkness, when the Moon disappeared, the poorly educated Indians were very frightened and supplied the travelers with everything they needed. They begged for the heavenly body to be returned to them, to which Columbus agreed. Thus, the expedition managed to avoid starvation.

How to watch a lunar eclipse

The characteristics of lunar eclipses have already become available to you, but why are they so interesting to researchers? There are some scientific benefits to be gained from observing lunar eclipses. Scientists collect and record materials about the state of the structure of the Earth's shadow and the upper layers of the atmosphere. Amateur astronomers often photograph eclipses and make sketches of them, describing changes in the brightness of objects located on the lunar surface. The moments of the Moon touching the shadow and those when it leaves its limits are accurately recorded. The moments of contact of the shadow with the largest objects on the lunar surface are also noted. Observations can be made with the naked eye, using binoculars or a telescope. It is clear that the technique helps to more accurately record the results of observations.

In order to make observations most accurately, you need to set your telescope to maximum magnification, pointing it directly at the points of contact between the shadow and the lunar surface. This must be done in advance, a few minutes before the expected eclipse. Usually all results are recorded in a special journal of lunar eclipse observations.

The same photo exposure meter

If an amateur astronomer has at his disposal a photoexposure meter (a special device that allows one to measure the brightness of an object), he can independently plot the change in the brightness of the Moon’s disk throughout the entire eclipse. To do this correctly, it is necessary to install the device so that its sensitive element is directed towards the center of the lunar disk.

A lunar eclipse is a natural phenomenon during which the Moon enters the Earth's shadow. When a lunar eclipse occurs, the Moon, the Sun and the Earth should be located on the line at the same time. It turns out that the Moon is blocked from the Sun with the help of the Earth. This means that an eclipse is possible only during a full moon. At this time, you can see the Moon, which is completely or partially obscured from the Earth. It is possible to observe an eclipse from that part of our planet that is located above the horizon.

Partial lunar eclipse

The diameter of the Earth's shadow is 2.5 times greater than the lunar shadow, which is why the Earth's shadow covers the entire disk of the Moon. In a situation where this happens, the eclipse is total. If the Moon is partially immersed in the Earth's shadow, then such an eclipse is considered a partial eclipse.

In situations where the line of the Moon with the Sun and Earth is far from ideal, it is possible that the eclipse phase will not occur. It is also possible that the earth's shadow will affect the edge of the lunar disk, it will be covered with penumbra.

The duration of the phases of any eclipse, partial or total, depends directly on the location of all 3 of the above-mentioned celestial bodies. The longest duration of a lunar eclipse can be 108 minutes. The brightness of the lunar disk during a total lunar eclipse also depends on the same reason. There are cases when the Moon is not visible at all, and it also happens that the Moon is so bright that observers do not even believe that a lunar eclipse has occurred.

The penumbra that exists around the Earth's shadow cone can partially obscure the Sun. When the Moon begins to pass this area, but has not entered the shadow, a penumbral eclipse occurs. The brightness of the Moon becomes less, but only slightly. Such a decrease in brightness cannot be seen with the naked eye; only instruments can detect it.

Even when the lunar eclipse is total, the Moon does not disappear at all, becoming dark red. There is an explanation for this: with the onset of a total eclipse, the rays of the Sun illuminate the Moon further. These rays shine tangentially on the earth's surface, are refracted, and then scattered in the earth's atmosphere.

The Earth's atmosphere is capable of absorbing short-wavelength spectral parts of blue and blue hues, but at the same time transmitting red ones without problems. They reach the lunar surface during an eclipse. This phenomenon has the same nature that is observed in the sun's rays coloring the western part of the sky in a soft pink color.

Once, after during one of the expeditions of Christopher Columbus, all food supplies and water on the ship came to an end, and attempts to negotiate with the Indians did not bring success, knowledge of the approaching lunar eclipse provided the navigator with a colossal service.

He told the local residents that if they did not send him food by the evening, he would take away the night star from them. They only laughed in response, but when the moon began to darken at night and acquired a crimson hue, they were simply horrified. Water and food supplies were immediately delivered to the ship, and the Indians on their knees asked Columbus to return the luminary to the sky. The navigator could not refuse their request - and a few minutes later the Moon shone in the sky again.

A lunar eclipse can be seen on a full moon, when its shadow falls on the Earth’s satellite (for this, the planet must be between the Sun and the Moon). Since the night star is separated from the Earth by at least 363 thousand km, and the diameter of the shadow cast by the planet is two and a half times the diameter of the satellite, when the Moon is covered by the Earth's shadow, it turns out to be completely darkened.

This does not always happen: sometimes the shadow partially covers the satellite, and sometimes it does not reach the shadow and ends up near its cone, in the penumbra, when only a slight darkening of one of the edges of the satellite is noticeable. Therefore, in lunar calendars, the degree of darkness is measured in values ​​from 0 and F:

• The beginning and end of the partial (partial) period of the eclipse – 0;
• The beginning and end of the private phase – from 0.25 to 0.75;
• Beginning and end of the total period of the eclipse – 1;
• The period of the highest phase is 1.005.

Lunar nodes

One of the indispensable conditions necessary for the occurrence of a total lunar eclipse is the proximity of the Moon to the node (at this point the lunar orbit intersects the ecliptic).

Since the plane of the orbit of the night star is inclined to the plane of the earth's orbit at an angle of five degrees, the satellite, crossing the ecliptic, moves towards the North Pole, upon reaching which it turns in the opposite direction and moves down to the South. The points where the satellite's orbit intersects the points of the ecliptic are called lunar nodes.

When the Moon is near a node, a total lunar eclipse can be seen (usually every six months). It is interesting that it is not typical for the lunar nodes to constantly remain at one point on the ecliptic, since they constantly move along the line of the Zodiac constellations against the course of the Sun and Moon, making one revolution every 18 years and 6 months. Therefore, it is best to determine when the next total lunar eclipse will be using the calendar. For example, if they occurred in November and May, then next year they will occur in October and April, then in September and March.

When a miraculous phenomenon occurs

If the Moon's orbit always coincided with the ecliptic line, eclipses would occur every month and would be an absolutely common occurrence. Since the satellite is mainly located above or below the Earth's orbit, the shadow of our planet covers it two, maximum three times a year.

At this time, the new or full Moon is just near one of its nodes (within twelve degrees on either side), and the Sun, Earth and Moon are located on the same line. In this case, you can first see a solar eclipse, and two weeks later, during the full phase of the moon, a lunar eclipse (these two types of eclipses always come in pairs).

It happens that a lunar eclipse does not occur at all: this happens when the Sun, Earth and Moon are not on the same line at the right moment, and the earth’s shadow either passes by the satellite or affects it with penumbra. True, the event is practically indistinguishable from Earth, since the brightness of the satellite at this time decreases only slightly and can only be seen through telescopes (if the Moon, being in a penumbral eclipse, passes very close to the shadow cone, you can see a slight darkening on one side) . If the satellite is only partially in the shadow, a partial lunar eclipse occurs: part of the celestial body darkens, the other remains in partial shade and is illuminated by the rays of the Sun.

How does an eclipse occur?

Since the Earth’s shadow is much larger than its satellite, it sometimes takes a lot of time for the night star to pass it, so a total lunar eclipse can last either a very short period of time, about four to five minutes, or more than an hour (for example, the maximum recorded duration of the phase on the night of the lunar eclipse was 108 minutes).

The duration of this phenomenon will largely depend on the location of the three heavenly bodies to each other.

If you observe the Moon from the northern hemisphere, you can see that the Earth's penumbra covers the Moon on the left side. After half an hour, the satellite of our planet is completely in the shadow - and on the night of a lunar eclipse, the star acquires a dark red or brown tint. The sun's rays illuminate the satellite even during a total eclipse and, passing along a tangent line relative to the earth's surface, are scattered in the atmosphere, reaching the night star.

Since red has the longest wavelength, it, unlike other colors, does not disappear and reaches the lunar surface, illuminating it with a red color, the hue of which largely depends on the state of the earth's atmosphere at a given moment. The brightness of the satellite on the night of a lunar eclipse is determined by a special Danjon scale:

• 0 – total lunar eclipse, the satellite will be almost invisible;
• 1 – The moon is dark gray;
• 2 – Earth satellite of gray-brown color;
• 3 – the Moon is characterized by a reddish-brown tint;
• 4 is a copper-red satellite, visible very clearly and all the details of the lunar surface are clearly visible.

If you compare photos that were taken on the night of a lunar eclipse at different times, you will notice that the color of the Moon is different. For example, the Earth's satellite during the summer eclipse of 1982 was red, while in the winter of 2000 the Moon was brown.

History of the lunar calendar

People have long understood how important the role the Moon plays in the life of the planet, and therefore they planned all their activities based on its phases (new moon, full moon, waning, eclipses), since they were the most observed celestial phenomena.

It is not surprising that the lunar calendar is considered the most ancient calendar in the world: it was by it that people in the early stages of their development determined when to start and finish sowing work, observed the influence of the Moon on the growth of vegetation, the ebb and flow of tides, and even how night the luminary affects the human body, which, as is known, contains a large amount of liquids.

It is impossible to determine which people were the first to create the lunar calendar. The first objects that were used as lunar calendars were found in France and Germany and were created thirty thousand years ago. These were crescent-shaped marks or sinuous lines on cave walls, stones or animal bones.

Also found were lunar calendars created eighteen thousand years ago in Russia near the city of Achinsk in the Krasnoyarsk Territory. A calendar was also found in Scotland, which is at least ten thousand years old.

The Chinese gave a modern look to the lunar calendar, who already in the 2nd millennium BC. formed the main provisions and used it until the 20th century. Also, an important role in the development of the lunar calendar belongs to the Hindus, who were the first to give basic descriptions of the phases, lunar days and positions of the Moon relative to the Earth and the Sun.

The lunar calendar was replaced by a solar one, since during the formation of a sedentary lifestyle it became obvious that agricultural work was still more tied to the seasons, that is, to the Sun. The lunar calendar turned out to be inconvenient due to the fact that the lunar month does not have a stable time and is constantly shifted by 12 hours. There is one extra lunar year for every 34 solar years.

Nevertheless, the Moon exerted sufficient influence. For example, the modern Gregorian calendar, adopted about five hundred years ago, contains such statements, drawn from lunar calendars, as the number of days in the week and even the term “month”.

Astronomical knowledge is an interesting part of the general knowledge required for a person to understand what is happening in the environment. We direct our gaze to the sky whenever dreams take over our minds. Sometimes certain phenomena strike a person to the core. We will talk about these in our article, namely what a lunar and solar eclipse is.

Although today the disappearance or partial concealment of luminaries from our eyes does not cause such superstitious fear as it did among our ancestors, a special aura of mystery of these processes remains. Nowadays, science has facts that can be used to explain this or that phenomenon in a simple and accessible way. We will try to do this in today’s article.

and how does it happen?

A solar eclipse is one that occurs as a result of the Earth's satellite eclipsing the entire solar surface or part of it facing observers located on the ground. However, it is possible to see it only during the new moon, when the part of the Moon facing the planet is not completely illuminated, that is, it becomes invisible to the naked eye. We understand what an eclipse is, and now we will find out how it happens.

An eclipse occurs when the Moon is not illuminated by the Sun from the side visible on Earth. This is possible only in the growing phase, when it is near one of the two lunar nodes (by the way, the lunar node is the point of intersecting lines of two orbits, solar and lunar). Moreover, the lunar shadow on the planet has a diameter of no more than 270 kilometers. Therefore, it is possible to observe an eclipse only at the location of the passing shadow strip. In turn, the Moon, rotating in orbit, maintains a certain distance between it and the Earth, which at the moment of an eclipse can be completely different.

When do we observe a total solar eclipse?

You've probably heard about the concept of a total eclipse. Here we will once again clearly outline what a total solar eclipse is and what conditions are needed for it.

The shadow of the Moon falling on the Earth is a certain spot of a certain diameter with a possible change in size. As we have already said, the diameter of the shadow does not exceed 270 kilometers, while the minimum figure is approaching zero. If at this moment the observer of the eclipse finds himself in a dark stripe, he has a unique opportunity to witness the complete disappearance of the Sun. At the same time, the sky becomes dark, with the outlines of stars and even planets. And around the previously hidden solar disk, the outline of a corona appears, which is impossible to see in normal times. A total eclipse lasts no more than a few minutes.

The photographs of this unique phenomenon presented in the article will help you see and understand what a solar eclipse is. If you decide to observe this phenomenon live, you must follow safety precautions regarding vision.

With this, we finished the information block in which we learned what a solar eclipse is and what conditions are necessary to see it. Next we have to get acquainted with the lunar eclipse, or, as it sounds in English, lunar eclipse.

What is a lunar eclipse and how does it happen?

A lunar eclipse is a cosmic phenomenon that occurs when the Moon falls into the shadow of the Earth. At the same time, as with the Sun, events can have several development options.

Depending on certain factors, a lunar eclipse can be total or partial. Logically, we can well assume what this or that term that characterizes a particular eclipse means. Let's find out what a total lunar eclipse is.

How and when does a planet's satellite become invisible?

Such an eclipse of the Moon is usually visible where it is located above the horizon at the appropriate moment. The satellite appears in the shadow of the Earth, but at the same time a total eclipse is not able to hide the Moon completely. In this case, it is only slightly shaded, acquiring a dark, reddish tint. This happens because, even being completely in the shadow, the lunar disk does not cease to be illuminated by the sun's rays passing through the earth's atmosphere.

Our knowledge has expanded with facts about the lunar eclipse. However, these are not all the possible options for the eclipse of a satellite by the earth's shadow. We'll talk about the rest further.

Partial lunar eclipse

As in the case of the Sun, the darkening of the visible surface of the Moon is often incomplete. We can observe a partial eclipse when only a certain part of the Moon is in the shadow of the Earth. This means that when part of the satellite is eclipsed, that is, obscured by our planet, then its second part continues to be illuminated by the Sun and remains clearly visible to us.

A penumbral eclipse will seem much more interesting and unusual, differing from others in astronomical processes. We will talk further about what a penumbral lunar eclipse is.

Unique penumbral lunar eclipse

This type of eclipse of the Earth's satellite occurs a little differently than a partial eclipse. It is easy to find out from open sources or from your own experience that there are areas on the surface of the Earth where the sun's rays are not completely obscured, and therefore cannot be a shadow. But there is no direct sunlight either. This is the penumbra region. And when the Moon, which finds itself in this very place, finds itself in the penumbra of the Earth, we can observe a penumbral eclipse.

When entering the penumbral region, the lunar disk changes its brightness, becoming slightly darker. True, such a phenomenon is almost impossible to notice and recognize with the naked eye. For this you will need special devices. It is also interesting that at one edge of the Moon's disk the darkening may be more noticeable.

So we have finished the second main block of our article. Now we can easily explain ourselves what a lunar eclipse is and how it happens. But the interesting facts about solar and lunar eclipses don't end there. Let's continue the topic by answering some questions related to these amazing phenomena.

Which eclipses occur more often?

After everything that we have learned from the previous parts of the article, the question naturally arises: which of the eclipses do we have a better chance of seeing in our lives? Let's also say a few words about this.

It’s incredible, but true: the number of eclipses of the Sun is greater, even though the Moon is smaller in size than. After all, knowing what an eclipse is and why it occurs, one might think that the shadow of a larger object is more likely to block a smaller one than vice versa. Based on this logic, the size of the Earth allows us to hide the lunar disk in no time.
Nevertheless, it is precisely solar eclipses that happen more often on the planet. According to statistics from astronomers and observers, for every seven eclipses there are only three lunar and solar eclipses, respectively, four.

The reason for the amazing statistics

The disks of the celestial bodies closest to us, the Sun and the Moon, are almost identical in diameter in the sky. It is for this reason that solar eclipses can occur.

Typically, solar eclipses occur during the new moon period, that is, when the Moon approaches its orbital nodes. And since it is not perfectly round, and the nodes of the orbit move along the ecliptic, during favorable periods the disk of the Moon on the celestial sphere can be either larger, smaller, or even equal to the solar disk.

In this case, the first case contributes to a total eclipse. The decisive factor is the angularity. At its maximum size, the eclipse can last up to seven and a half minutes. The second case involves complete shading for just seconds. In the third case, when the moon's disk is smaller than the sun's, a very beautiful eclipse occurs - an annular one. Around the dark disk of the Moon we see a shining ring - the edges of the solar disk. This eclipse lasts 12 minutes.

Thus, we have supplemented our knowledge of what a solar eclipse is and how it occurs with new details worthy of amateur researchers.

Eclipse factor: location of luminaries

An equally important reason for an eclipse is the uniform distribution of heavenly bodies. The Moon's shadow may or may not fall on the Earth. And sometimes it happens that only the penumbra of an eclipse falls on the Earth. In this case, you can observe a partial, that is, incomplete eclipse of the Sun, which we already talked about when we talked about what a solar eclipse is.

If a lunar eclipse can be observed from the entire night surface of the planet, from which the circumference of the lunar disk is visible, then a solar eclipse can only be observed when you are in a narrow strip with an average width of 40-100 kilometers.

How often can you see eclipses?

Now that we know what an eclipse is and why some happen more than others, one more exciting question remains: how often can these amazing phenomena be observed? After all, in our lives, each of us has heard only one piece of news about an eclipse, a maximum of two, some - not a single one...

Despite the fact that a solar eclipse occurs more often than a lunar eclipse, it can still be seen in the same area (remember the strip with an average width of 40-100 kilometers) only once every 300 years. But a person can observe a total lunar eclipse several times in his life, but only if the observer has not changed his place of residence throughout his life. Although today, knowing about the blackout, you can get anywhere and by any means of transport. Those who know what a lunar eclipse is will probably not stop walking a hundred or two kilometers for the incredible spectacle. Today there are no problems with this. And if you suddenly receive information about the next eclipse in some place, do not be lazy and spare no expense in order to get to the place of maximum visibility at the moment when you can observe the eclipse taking place. Believe me, no distance can compare with the impressions received.

Nearest visible eclipses

You can learn about the frequency and schedule of eclipses from the astronomical calendar. In addition, significant events such as a total eclipse will definitely be discussed in the media. The calendar says that the next solar eclipse visible in the Russian capital will take place on October 16, 2126. Let us also recall that the last eclipse in this territory could be observed more than a hundred years ago - in 1887. So Moscow residents won’t have to watch a solar eclipse for many years. The only opportunity to see this amazing phenomenon is to go to Siberia, the Far East. There you can observe a change in the brightness of the Sun: it will only darken a little.

Conclusion

With our astronomical article, we tried to explain clearly and briefly what an eclipse of the Sun and Moon is, how these phenomena occur, and how often they can be seen. The conclusion of our research in this area: eclipses of different celestial bodies occur according to different principles and have their own characteristics. But understanding some of the details necessary for the average person to fully understand the environment is very important.

Nowadays, thanks to developed science and technology, the temporarily extinguished star is no longer frightening, but remains just as alluringly mysterious. Today we know what a lunar and solar eclipse are and what they bring to us. Let the interest in them now be purely cognitive as a rare outlandish phenomenon. Finally, we wish you to see at least one eclipse with your own eyes!

The Moon is the closest celestial body to the Earth, its only natural satellite. Being at a distance of about 380 thousand km from the Earth, the Moon revolves around it in the same direction in which the Earth rotates around its axis. Every day it moves relative to the stars by about 13°, making a full revolution in 27.3 days. This period of time - the period of revolution of the Moon around the Earth in a reference system associated with the stars - is called a sidereal or sidereal month (from the Latin sidus - star) month.

The Moon does not have its own glow, and the Sun illuminates only half of the lunar globe. Therefore, as it moves in orbit around the Earth, the appearance of the Moon changes - a change in lunar phases. At what time of day the Moon is above the horizon, how we see the hemisphere of the Moon facing the Earth - fully illuminated or partially illuminated - all this depends on the position of the Moon in orbit.

If it is positioned so that its dark, unlit side faces the Earth (position 1), then we cannot see the Moon, but we know that it is somewhere in the sky near the Sun. This phase of the moon is called the new moon. Moving in orbit around the Earth, the Moon will reach position 2 in about three days. At this time, it can be seen in the evenings near the setting Sun in the form of a narrow crescent, convexly facing to the right. At the same time, the rest of the Moon is often visible, which glows much weaker, the so-called ashen light. It is our planet, reflecting the sun's rays, that illuminates the night side of its satellite.

Day by day, the crescent moon increases in width, and its angular distance from the Sun increases. A week after the new moon, we see half of the illuminated hemisphere of the Moon - a phase called the first quarter begins. Subsequently, the proportion of the illuminated hemisphere of the Moon visible from Earth continues to increase until the full moon occurs. In this phase, the Moon is in the sky in the direction opposite to the Sun and is visible above the horizon all night - from sunset to sunrise. After the full moon, the phase of the moon begins to decrease. Its angular distance from the Sun also decreases. First, a small damage appears on the right edge of the lunar disk, which has the shape of a sickle. Gradually this damage increases (position 6), and a week after the full moon the last quarter phase begins. In this phase, as in the first quarter, we again see half of the illuminated hemisphere of the Moon, but now the other, which was unlit in the first quarter. The moon rises late and is visible in this phase in the morning. Subsequently, its crescent, now convexly facing to the left, becomes more and more narrow (position 8), gradually approaching the Sun. In the end, he disappears into the rays of the rising Sun - the new moon comes again.

The full cycle of changing lunar phases is 29.5 days. This period of time between two successive identical phases is called a synodic month (from the Greek synodos - connection). Even in ancient times, for many peoples, the month, along with the day and year, became one of the main calendar units. It is not difficult to understand why the synodic month is longer than the sidereal month if we remember that the Earth moves around the Sun. After 27.3 days, the Moon will take its previous position in the sky relative to the stars and will be at point L1. During this time, the Earth, moving by 1° per day, will pass an arc of 27° along its orbit and end up at point T1. The Moon, in order to be at the L2 new moon again, will have to go through the same arc in its orbit (27°). This will take a little more than two days, since the Moon moves by 13° per day. Only one side of the Moon is visible from Earth, but this does not mean that it does not rotate around its axis. Let's conduct an experiment with the globe of the Moon, moving it around the globe of the Earth so that one side of the lunar globe is always facing it. This can only be achieved if we rotate it in relation to all other objects in the classroom.

A full revolution of the globe of the Moon around its axis will be completed simultaneously with the completion of one revolution around the globe of the Earth. This proves that the period of rotation of the Moon around its axis is equal to the sidereal period of its revolution around the Earth - 27.3 days. If the orbital plane along which the Moon moves around the Earth coincided with the orbital plane along which the Earth revolves around the Sun, then a solar eclipse would occur every month at the moment of the new moon, and a lunar eclipse at the moment of the full moon. This does not happen because the plane of the lunar orbit is inclined to the plane of the Earth's orbit at an angle of about 5°. That is why, on a new moon, the shadow of the Moon can pass above the Earth, and on a full moon, the Moon itself can pass below the Earth's shadow. At this time, the position of the Moon's orbit is such that it intersects the plane of the Earth's orbit in the first and last quarter phases. In what cases can eclipses of the Sun and Moon occur? You already know that the direction of the Earth’s rotation axis in space remains unchanged when our planet moves around the Sun.

The position of the lunar orbital plane remains virtually unchanged throughout the year. Let's consider how this will affect the possibility of eclipses. In three months, the Earth will travel a quarter of its way around the Sun and take up its position. Now the plane of the lunar orbit will be located so that the line of its intersection with the plane of the earth's orbit is directed towards the Sun. Therefore, the Moon will cross the plane of the Earth's orbit (or be close to it) during the new moon and full moon. In other words, moving across the sky, the Moon comes to that point on the ecliptic where the Sun is at that moment, and blocks it from us. If the Sun is completely covered by the Moon, the eclipse is called total. If it happens that it covers only part of the Sun, then the eclipse will be partial. When the Moon crosses the ecliptic at a point diametrically opposite to the Sun, it itself is completely or partially hidden in the shadow of the Earth.

Lunar eclipses, like solar eclipses, can be total or partial. Conditions favorable for the onset of eclipses persist for about a month. During this time, at least one solar eclipse or two solar and one lunar eclipse can occur. The next location of the lunar orbit necessary for the onset of eclipses will be repeated again only after about six months (177 - 178 days), when the Earth has passed half of its path around the Sun. During the year, two or three solar eclipses and one or two lunar eclipses usually occur on Earth. The maximum number of eclipses per year is seven. Lunar eclipses, although they occur less frequently than solar eclipses, are visible more often. The Moon, which falls into the Earth's shadow during an eclipse, is visible throughout the Earth's hemisphere, where it is above the horizon at that time.

Plunging into the earth's shadow, the Moon acquires a reddish color of various shades. The color depends on the state of the earth's atmosphere, which, while refracting the rays of the Sun and scattering them, still transmits red rays inside the shadow cone. It takes the Moon several hours to cross the Earth's shadow. The total phase of the eclipse lasts about one and a half hours. A total eclipse of the Sun can be observed only where a small (no more than 270 km in diameter) spot of the lunar shadow falls on the Earth. The Moon's shadow moves at a speed of approximately 1 km/s across the earth's surface from west to east, so at each point on the Earth a total eclipse lasts only a few minutes (at the equator the maximum duration is 7 minutes 40 s). The path that the Moon's shadow travels is called the streak of a total solar eclipse.

In different years, the lunar shadow runs across different regions of the globe, so total solar eclipses are visible less frequently than lunar ones. So, for example, in the vicinity of Moscow the last time an eclipse occurred was on August 19, 1887, and the next time it will occur only on September 16, 2126. The penumbra of the Moon has a diameter significantly larger than the shadow - about 6000 km. Where the Moon's penumbra falls, a partial eclipse of the Sun occurs. They can be seen every two to three years. Every 6585.3 days (18 years 11 days 8 hours) eclipses are repeated in the same order. This is the period of time during which the plane of the lunar orbit makes a complete revolution in space. Knowledge of the patterns of movement of the Moon and the Earth allows scientists to calculate the moments of eclipses with a high degree of accuracy hundreds of years in advance and know where on the globe they will be visible. Information about eclipses for the coming year and the conditions for their visibility are contained in the Astronomical Calendar, and here for a longer period. Having the necessary data on upcoming eclipses, scientists have the opportunity to organize expeditions during the total solar eclipse. At the moment of the full phase, one can observe the outer, most rarefied layers of the Sun's atmosphere - the solar corona, which is not visible under normal conditions. In the past, many important information about the nature of the Sun was obtained during total eclipses.