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Solar eclipse- an astronomical phenomenon, which consists in the fact that the Moon covers (eclipses) completely or partially the Sun from an observer on Earth. A solar eclipse is only possible during new moons, when the side of the Moon facing the Earth is not illuminated and the Moon itself is not visible. Eclipses are only possible if the new moon occurs near one of the two lunar nodes (the point where the visible orbits of the Moon and the Sun intersect), no more than about 12 degrees from one of them. The Moon's shadow on the earth's surface does not exceed 270 km in diameter, so a solar eclipse is observed only in a narrow strip along the path of the shadow. Since the Moon revolves in an elliptical orbit, the distance between the Earth and the Moon at the time of an eclipse can be different; accordingly, the diameter of the lunar shadow spot on the Earth’s surface can vary widely from maximum to zero (when the top of the lunar shadow cone does not reach the Earth’s surface). If the observer is in the shadow, he sees a total solar eclipse in which the Moon completely hides the Sun, the sky darkens, and planets and bright stars may appear on it.

Around the solar disk hidden by the Moon, you can observe the solar corona, which is not visible in the normal bright light of the Sun. When an eclipse is observed by a stationary ground-based observer, the total phase lasts no more than a few minutes. The minimum speed of movement of the lunar shadow on the earth's surface is just over 1 km/s. During a total solar eclipse, astronauts in orbit can observe the running shadow of the Moon on the Earth's surface.

Observers close to the total eclipse may see it as a partial solar eclipse. During a partial eclipse, the Moon passes across the disk of the Sun not exactly in the center, hiding only part of it. At the same time, the sky darkens much less than during a total eclipse, and the stars do not appear. A partial eclipse can be observed at a distance of about two thousand kilometers from the total eclipse zone.

The totality of a solar eclipse is also expressed by phase F. The maximum phase of a partial eclipse is usually expressed in hundredths of unity, where 1 is the total phase of the eclipse. The total phase can be greater than unity, for example 1.01, if the diameter of the visible lunar disk is greater than the diameter of the visible solar disk. Partial phases have a value less than 1. At the edge of the lunar penumbra, the phase is 0.

The moment when the leading/rear edge of the Moon's disk touches the edge of the Sun is called touching. The first touch is the moment when the Moon enters the disk of the Sun (the beginning of an eclipse, its partial phase). The last touch (the fourth in the case of a total eclipse) is the last moment of the eclipse, when the moon leaves the disk of the Sun. In the case of a total eclipse, the second touch is the moment when the front of the Moon, having passed across the entire Sun, begins to emerge from the disk. A total solar eclipse occurs between the second and third touches.

According to astronomical classification, if an eclipse at least somewhere on the Earth's surface can be observed as total, it is called total. If the eclipse can only be observed as a partial eclipse (this happens when the cone of the Moon's shadow passes close to the earth's surface, but does not touch it), the eclipse is classified as a partial eclipse. When an observer is in the shadow of the Moon, he is observing a total solar eclipse. When he is in the penumbra region, he can observe a partial solar eclipse. In addition to total and partial solar eclipses, there are annular eclipses. An annular eclipse occurs when, at the time of the eclipse, the Moon is further away from the Earth than during a total eclipse, and the cone of the shadow passes over the Earth's surface without reaching it. Visually, during an annular eclipse, the Moon passes across the disk of the Sun, but it turns out to be smaller in diameter than the Sun, and cannot hide it completely. In the maximum phase of the eclipse, the Sun is covered by the Moon, but around the Moon a bright ring of the uncovered part of the solar disk is visible. During an annular eclipse, the sky remains bright, stars do not appear, and it is impossible to observe the solar corona. The same eclipse can be seen in different parts eclipse bands as total or annular. This type of eclipse is sometimes called a total annular (or hybrid) eclipse.

From 2 to 5 solar eclipses can occur on Earth per year, of which no more than two are total or annular. On average, 237 solar eclipses occur per hundred years, of which 160 are partial, 63 are total, 14 are annular. At a certain point on the earth's surface, eclipses in a large phase occur quite rarely, and total solar eclipses are observed even more rarely.

Moon eclipse

Moon eclipse- an eclipse that occurs when the Moon enters the cone of the shadow cast by the Earth. The diameter of the Earth's shadow spot at a distance of 363,000 km (the minimum distance of the Moon from the Earth) is about 2.5 times the diameter of the Moon, so the entire Moon may be obscured. At each moment of the eclipse, the degree of coverage of the Moon's disk by the earth's shadow is expressed by the eclipse phase F. The magnitude of the phase is determined by the distance 0 from the center of the Moon to the center of the shadow. Astronomical calendars give the values ​​of Ф and 0 for different moments of the eclipse.

When the Moon completely enters the Earth's shadow during an eclipse, it is called a total lunar eclipse; when it partially enters, it is called a partial eclipse. A lunar eclipse can be observed over half of the Earth's territory (where the Moon is above the horizon at the time of the eclipse). The appearance of the shadowed Moon from any observation point differs negligibly from another point, and is the same. The maximum theoretically possible duration of the total phase of a lunar eclipse is 108 minutes; such were, for example, lunar eclipses on August 13, 1859, July 16, 2000.

During an eclipse (even a total one), the Moon does not disappear completely, but turns dark red. This fact is explained by the fact that the Moon continues to be illuminated even in the phase of total eclipse. The sun's rays passing tangentially to the earth's surface are scattered in the earth's atmosphere and due to this scattering they partially reach the moon. Because the earth's atmosphere it is most transparent for rays of the red-orange part of the spectrum; it is these rays that reach the surface of the Moon to a greater extent during an eclipse, which explains the color of the lunar disk. Essentially, this is the same effect as the orange-red glow of the sky near the horizon (dawn) before sunrise or just after sunset. The Danjon scale is used to assess the brightness of an eclipse.

Phases of a lunar eclipse

An observer located on the Moon, at the moment of a total (or partial, if he is on the shadowed part of the Moon) lunar eclipse sees a total solar eclipse (eclipse of the Sun by the Earth).

If the Moon falls into full shade The Earth is only partially visible, a partial eclipse is observed. With it, part of the Moon is dark, and part, even in its maximum phase, remains in partial shade and is illuminated by the sun's rays.

Views of the Moon during a lunar eclipse

Around the cone of the Earth's shadow there is a penumbra - a region of space in which the Earth only partially obscures the Sun. If the Moon passes through the penumbral region but does not enter the umbra, a penumbral eclipse occurs. With it, the brightness of the Moon decreases, but only slightly: such a decrease is almost imperceptible naked eye and is recorded only by instruments. Only when the Moon in a penumbral eclipse passes near the cone of total shadow can a slight darkening at one edge of the lunar disk be noticed in a clear sky.

At least two lunar eclipses occur every year, but due to the mismatch of the planes of the lunar and earth's orbits, their phases are different. Eclipses repeat in the same order every 6585 days (or 18 years 11 days and 8 hours - a period called saros); Knowing where and when a total lunar eclipse was observed, you can accurately determine the time of subsequent and previous eclipses that are clearly visible in this area. This cyclicality often helps to accurately date events described in historical records.

Instructions

As you know, the Moon is the only natural satellite of the Earth. On earth's horizon it is the brightest object after the Sun. In its orbital movement, the Moon, at different periods of time, appears either between our planet and the Sun, or on the other side of the Earth. The Earth is constantly illuminated by the Sun and casts space a cone-shaped shadow, the diameter of which at the minimum distance to the Moon is 2.5 times its diameter.

The plane of the Moon's orbit is located at an angle of about 5° to the plane of the ecliptic.
If we take into account the precession of the earth's axis and the plane of the lunar orbit and take into account the disturbances caused by the Sun and other planets solar system, it becomes clear that the Moon’s orbital movement changes periodically.

At some points in time, the Sun, Earth and Moon may be on the same or almost on the same line, and the Earth's shadow will partially or completely cover the Moon. This astronomical event is called a lunar eclipse. If the lunar disk is completely immersed in the region of the earth's shadow, a total lunar eclipse occurs. During partial immersion, a partial eclipse is observed. The total eclipse phase may not occur at all.

Even during a total eclipse, the lunar disk is visible in the sky. The moon is illuminated by the sun's rays passing tangentially to the earth's surface. The earth's atmosphere is most permeable to rays of the red-orange spectrum. Therefore, during an eclipse, the lunar disk becomes dark red and not so bright. There will be 2 total lunar eclipses in 2014 - April 15 and October 8. It is clear that an eclipse can only be observed in that part of the globe where the Moon is above the horizon at the time it passes through the shadow region. The maximum duration of a total lunar eclipse is 108 minutes.

During a partial eclipse, the earth's shadow covers only part of the lunar disk. From Earth, an observer will see a somewhat blurred boundary between the illuminated and shadowed parts of the Moon due to light scattering by the atmosphere. Shaded areas take on a reddish tint.

As you know, light rays are able to bend around obstacles. This phenomenon is called diffraction. Thus, around the cone of complete shadow in space there is a partially illuminated area - penumbra. Direct Sun rays they don't get in there. If the Moon passes through this area, a penumbral eclipse is observed. The brightness of its glow decreases slightly. As a rule, an eclipse cannot even be noticed without special instruments. Penumbral eclipses are of no interest to astronomers.

The moon does not have its own light, but its surface reflects the sun's rays, so it serves as our night luminary. During eclipses, our satellite turns red, which is why lunar eclipses are sometimes called “blood moons.”

Why do lunar eclipses occur?

These celestial phenomena occur when the Sun, Earth and Moon line up in a straight line. The Sun is behind the Earth, as a result the Earth casts a shadow on the Moon, and a lunar eclipse occurs.

They always occur on a full moon, but we cannot observe a lunar eclipse on every full moon. This is because the Moon's orbit is inclined at an angle of 5 degrees to the Earth's orbital plane, also known as the ecliptic (Earth's path around the Sun). The points where the two orbits intersect are called the lunar nodes, and eclipses can only occur when the full moon occurs near the lunar node. In other cases, the Earth cannot cast a shadow on the surface of the Moon.

Thus, for a lunar eclipse to occur, two conditions must be met:

Full Moon in the heavens;

The proximity of the Earth to one of the lunar nodes.

Types of lunar eclipses

There are 3 types: full, partial and penumbra.

A total lunar eclipse occurs when the central (dark) part of the Earth's shadow covers the entire visible side of the Moon. The Earth's shadow is about 1.4 million kilometers wide.

A partial lunar eclipse can be observed when only part of the visible surface of the Moon is covered by the Earth's shadow.

When the Sun, Earth and Moon are not in a perfectly level line, only the outer part of the Earth's shadow (penumbra) eclipses the Moon. Such an eclipse is called a penumbral eclipse.

Why does the moon turn red

Even if the Earth completely blocks sunlight from hitting the surface of the Moon, our satellite is still visible in the sky. This occurs because the Earth's atmosphere refracts sunlight and indirectly illuminates the lunar surface. During a total lunar eclipse, the Moon darkens and turns red because the Earth's atmosphere is most permeable to rays of the red color spectrum. However, the Moon can also appear yellow, orange or brown because clouds and dust particles are present in the Earth's atmosphere, allowing waves of different lengths to reach the surface of our satellite.

Where can you see lunar eclipses?

This celestial phenomenon can be seen by everyone who is on the night side of the Earth. It can be observed with the naked eye. The chance of seeing a lunar eclipse is much higher than a solar eclipse (it is visible only in a narrow band in certain areas of the Earth), although both occur at similar intervals. Into one calendar year there may be two lunar eclipses (about six months apart), sometimes three, but in some years none occur.

Myths and beliefs about eclipses

The ancient Incas believed that lunar eclipses were caused by a jaguar trying to devour the moon. The red or blood-red color that the earth's satellite turns during a total lunar eclipse was explained by the attack of a big cat. The Incas were afraid that after attacking the Moon, a huge jaguar would crash to Earth and start eating people. They tried to drive him away with noise and screams, and teased the dogs to bark loudly.

However, jaguars were not the only predators in mythology that wanted to eat the heavenly body. The people of ancient Mesopotamia also saw eclipses as attacks on the moon, but in their story the attackers were seven demons. Other peoples had similar beliefs, which included bloodthirsty dragons and other mythical creatures.

The Hupa American Indians of Northern California believed that Luna had 20 wives and many animals, most of them mountain lions and snakes. If they did not bring enough food, they attacked and inflicted wounds, then the blood turned the Moon red. The eclipse ended when the wives came to protect them, drove away the predators and healed the Moon.

The Indians of Southern California believed that the eclipse signaled that the moon was ill, so they sang chants and prayed for her to return to health.

Not all ancient cultures attributed negative meanings to lunar eclipses. According to a myth from Benin, the Sun and Moon fight each other, and people come to their aid to judge them. The ancient people of Benin believed that in the days lunar eclipses we need to come together, resolve old feuds and restore good relations.

> 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. Full moon and new moon entering the zone Lunar nodes relates lunar and solar eclipses.

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

Incredibly beautiful cosmic phenomenon which is observed 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. 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 this event (08/27/413 BC).

Quite famous 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.

A lunar eclipse occurs when the Moon (in its full moon phase) enters the cone of the shadow cast by the Earth. The diameter of the Earth's shadow spot at a distance of 363,000 km (the minimum distance of the Moon from the Earth) is about 2.5 times the diameter of the Moon, so the entire Moon may be obscured. A lunar eclipse can be observed over half of the Earth's territory (where the Moon is above the horizon at the time of the eclipse). The view of the shadowed Moon from any observation point is the same. The maximum theoretically possible duration of the total phase of a lunar eclipse is 108 minutes; such were, for example, lunar eclipses on August 13, 1859, July 16, 2000.

At each moment of the eclipse, the degree of coverage of the Moon's disk by the earth's shadow is expressed by the eclipse phase F. The magnitude of the phase is determined by the distance 0 from the center of the Moon to the center of the shadow. Astronomical calendars give the values ​​of Ф and 0 for different moments of the eclipse.

If the Moon falls into the total shadow of the Earth only partially, it is observed partial eclipse. With it, part of the Moon is dark, and part, even in its maximum phase, remains in partial shade and is illuminated by the sun's rays.

Around the cone of the Earth's shadow there is a penumbra - a region of space in which the Earth only partially obscures the Sun. If the Moon passes through the penumbra region, but does not enter the shadow, it occurs penumbral eclipse. With it, the brightness of the Moon decreases, but only slightly: such a decrease is almost imperceptible to the naked eye and is recorded only by instruments. Only when the Moon in a penumbral eclipse passes near the cone of total shadow can a slight darkening at one edge of the lunar disk be noticed in a clear sky.

An eclipsed Moon flickers in the sky above the Monument to the Savior of the World in San Salvador, El Salvador, December 21, 2010.

(Jose CABEZAS/AFP/Getty Images)

When a total eclipse occurs, the Moon takes on a reddish or brownish hue. The color of the eclipse depends on the state of the upper layers of the earth's atmosphere, since only the light passing through it illuminates the Moon during a total eclipse. If you compare photographs of total lunar eclipses from different years, you can easily see the difference in color. For example, the eclipse of July 6, 1982 was reddish, while the eclipse of January 20, 2000 was brown. The Moon acquires these colors during eclipses due to the fact that the earth's atmosphere scatters red rays more, so you can never observe, say, a blue or green lunar eclipse. But total eclipses differ not only in color, but also in brightness. Yes, exactly, brightness, and there is a special scale for determining the brightness of a total eclipse, called the Danjon scale (in honor of the French astronomer Andre Danjon, 1890–1967).

The Danjon scale has 5 points. 0 - very dark eclipse (the Moon can barely be seen in the sky), 1 - dark gray eclipse (details are visible on the Moon), 2 - gray eclipse with a brown tint, 3 - light red-brown eclipse, 4 - very light copper-red eclipse (The moon is clearly visible, and all the main surface details are visible.)

If the plane of the lunar orbit lay in the plane of the ecliptic, then lunar (as well as solar) eclipses would occur monthly. But the Moon spends most of its time either above or below the plane of the Earth's orbit due to the fact that the plane of the lunar orbit has a five-degree inclination to the plane of the Earth's orbit. As a result, the Earth's natural satellite falls into its shadow only twice a year, that is, at a time when the nodes of the lunar orbit (the points of its intersection with the ecliptic plane) are on the Sun-Earth line. Then on a new moon there is a solar eclipse, and on a full moon there is a lunar eclipse.

At least two lunar eclipses occur every year, but due to the mismatch of the planes of the lunar and earth's orbits, their phases are different. Eclipses repeat in the same order every 6585⅓ days (or 18 years 11 days and ~8 hours - a period called saros); Knowing where and when a total lunar eclipse was observed, you can accurately determine the time of subsequent and previous eclipses that are clearly visible in this area. This cyclicality often helps to accurately date events described in historical records. The history of lunar eclipses goes back a long way. The first total lunar eclipse was recorded in ancient Chinese chronicles. Using calculations, it was possible to calculate that it happened on January 29, 1136 BC. e. Three more total lunar eclipses are recorded in the Almagest of Claudius Ptolemy (March 19, 721 BC, March 8 and September 1, 720 BC). History often describes lunar eclipses, which is very helpful in establishing the exact date of a particular event. historical event. For example, the commander of the Athenian army, Nicias, was frightened by the onset of a total lunar eclipse, panic began in the army, which led to the death of the Athenians. Thanks to astronomical calculations, it was possible to establish that this happened on August 27, 413 BC. e.

In the Middle Ages, a total lunar eclipse did Christopher Columbus a great favor. His next expedition to the island of Jamaica was in dire straits, food and drinking water were running out, and people were in danger of starvation. Columbus's attempts to obtain food from the local Indians ended in vain. But Columbus knew that a total lunar eclipse was about to occur on March 1, 1504, and in the evening he warned the leaders of the tribes living on the island that he would steal the Moon from them if they did not deliver food and water to the ship. The Indians just laughed and left. But as soon as the eclipse began, the Indians were seized by indescribable horror. Food and water were immediately delivered, and the leaders on their knees begged Columbus to return the Moon to them. Columbus, naturally, could not “refuse” this request, and soon the Moon, to the delight of the Indians, shone in the sky again. As we can see, an ordinary astronomical phenomenon can be very useful, and knowledge of astronomy is simply necessary for travelers.

Observations of lunar eclipses can bring some scientific benefit, as they provide material for studying the structure of the earth's shadow and the state of the upper layers of the earth's atmosphere. Amateur observations of partial lunar eclipses come down to accurately recording the moments of contact, photographing, sketching and describing changes in the brightness of the Moon and lunar objects in the eclipsed part of the Moon. The moments of the lunar disk touching the earth's shadow and leaving it are recorded (with the greatest possible accuracy) by a clock calibrated using precise time signals. It is also necessary to note the contacts of the earth's shadow with large objects on the Moon. Observations can be made with the naked eye, binoculars or telescope. The accuracy of observations naturally increases when observing through a telescope. To register eclipse contacts, it is necessary to set the telescope to its maximum magnification and point it at the corresponding points of contact of the Moon’s disk with the earth’s shadow a few minutes before the predicted moment. All entries are recorded in a notebook (a journal of eclipse observations).

If an astronomy enthusiast has a photoexposure meter (a device that measures the brightness of an object), then it can be used to construct a graph of changes in the brightness of the lunar disk during the eclipse. To do this, you need to install the exposure meter so that its sensitive element is aimed exactly at the disk of the Moon. The readings from the device are taken every 2-5 minutes and recorded in the table in three columns: brightness measurement number, time and brightness of the Moon. At the end of the eclipse, using the table data, it will be possible to display a graph of changes in the brightness of the Moon during this astronomical phenomenon. Any camera that has an automatic exposure system with an exposure scale can be used as an exposure meter.

Photographing the phenomenon can be done with any camera that has a removable lens. When photographing an eclipse, the lens is removed from the camera, and the body of the device is adjusted to the eyepiece part of the telescope using an adapter. This will be shooting with ocular magnification. If the lens of your camera is not removable, then you can simply attach the camera to the telescope eyepiece, but the quality of such a picture will be worse. If your camera or video camera has the Zoom function, there is usually no need for additional magnifying tools, because The dimensions of the Moon at maximum magnification of such a camera are sufficient for filming.

Nevertheless, best quality images are obtained by photographing the Moon at the direct focus of a telescope. In such an optical system, the telescope lens automatically becomes a camera lens, only with a larger focal length.