School encyclopedia. Solar eclipse: Total solar eclipse, partial solar eclipse, annular eclipse

Everyone has seen such an astronomical phenomenon as a solar eclipse at least once in their life. Even in ancient sources, people mentioned it, and today at least once or twice a year you can see partial or complete eclipses all over the Earth. Eclipses occur regularly, several times a year, and even the exact dates of the next ones are known.

What is a solar eclipse?

Objects in outer space are located in such a way that the shadow of one can overlap another. The moon provokes a solar eclipse when it covers the fiery disk. At this moment, the planet becomes a little colder and noticeably darker, as if evening had come. Animals and birds get scared in this incomprehensible situation, plants roll up their leaves. Even people used to treat such astronomical jokes with great excitement, but with the development of science everything fell into place.

How does a solar eclipse occur?

The Moon and the Sun are at different distances from our planet, so they appear to people to be almost the same size. On a new moon, when the orbits of both cosmic bodies intersect at one point, the satellite closes the luminary to the earthly viewer. A solar eclipse is a bright and memorable astronomical situation, but it is impossible to fully enjoy it for several reasons:

The darkening band is not wide by earthly standards, no more than 200-270 km.
Due to the fact that the diameter of the Moon is much smaller than that of the Earth, the eclipse can only be seen in certain places on the planet.
The so-called “dark phase” lasts several minutes. After this, the satellite moves to the side, continuing to rotate in its orbit, and the luminary again “works as usual.”

What does a solar eclipse look like?

When the earth's satellite blocks a celestial body, the latter from the surface of the planet looks like a dark spot with a bright corona on the sides. The fireball is covered by another, but of smaller diameter. A pearl-colored glow appears around. These are the outer layers of the solar atmosphere, not visible during normal times. The “magic” lies in one moment, which can only be caught from a certain angle. And the essence of a solar eclipse is the shadow falling from the satellite, which blocks the light. Those in the darkened zone can see the full eclipse, while others can see only partially or not at all.

How long does a solar eclipse last?

Depending on the latitude at which a potential earthly viewer is located, he can observe the Eclipse for 10 to 15 minutes. During this time, there are three conventional stages of a solar eclipse:

The Moon appears from the right edge of the luminary.
It passes along its orbit, gradually obscuring the fiery disk from the viewer.
The darkest period begins - when the satellite completely obscures the star.

After this, the Moon moves away, revealing the right edge of the Sun. The glow ring disappears and it becomes light again. The last period of a solar eclipse is short-lived, lasting on average 2-3 minutes. The longest recorded duration of the full phase in June 1973 lasted 7.5 minutes. And the shortest eclipse was noticeable in 1986 in the north Atlantic Ocean, when a shadow obscured the disk for just one second.

Solar eclipse - types

The geometry of the phenomenon is amazing, and its beauty is due to the following coincidence: the diameter of the star is 400 times larger than the lunar one, and from it to the Earth is 400 times further. Under ideal conditions, you can see a very “accurate” eclipse. But when a person watching a unique phenomenon is in the penumbra of the Moon, he notices a partial darkness. There are three types of eclipse:

Total solar eclipse - if the darkest phase is visible to earthlings, the fiery disk is completely closed and there is a golden crown effect.
Partial when one edge of the Sun is obscured by a shadow.
An annular solar eclipse occurs when the earth's satellite is too far away, and when looking at the star, a bright ring is formed.

Why is a solar eclipse dangerous?

A solar eclipse is a phenomenon that has both attracted and terrified people since ancient times. Understanding its nature, there is no point in being afraid, but eclipses really carry colossal energy, which sometimes poses a danger to people. Doctors and psychologists consider the impact of these phenomena on the human body, arguing that hypersensitive people, the elderly and pregnant women are especially vulnerable. Three days before the event and three days after, health problems may arise such as:

headache;
pressure surges;
exacerbation of chronic diseases.

What should you not do during a solar eclipse?

From a medical point of view, looking at the sun during an eclipse is very dangerous, because the sun produces a large amount of ultraviolet radiation (and during an eclipse, the eyes are not protected and absorb dangerous doses of UV radiation), which is the cause of various eye diseases. Astrologers talk about the influence of a solar eclipse on people's lives and their behavior. Experts in this field do not recommend starting new businesses during this period in order to avoid failures, taking on something spontaneously and making difficult decisions on which your future fate depends. Some of the things you should not do during a solar eclipse include:

alcohol and drug abuse;
conflict resolution as people become more irritable;
carrying out complex medical procedures;
participation in mass actions.

When is the next solar eclipse?

In ancient times, the moment when the star disappeared behind the lunar disk could not be predicted. Nowadays, scientists name the exact dates and places where it is best to look beyond the eclipse and the moment of the maximum phase, when the Moon completely covers the fiery disk with its shadow. The calendar for 2018 is as follows:

Partial blackout will be visible in Antarctica, southern Argentina and Chile on the night of February 15, 2018.
On July 13, at southern latitudes (Australia, Oceania, Antarctica), partial occlusion of the Sun can be observed. Maximum phase – 06:02 Moscow time.
The nearest solar eclipse for residents of Russia, Ukraine, Mongolia, China, Canada and Scandinavia will occur on August 11, 2018 at 12:47.

Solar eclipse - interesting facts

Even people who do not understand astronomy are interested in how often a solar eclipse occurs, what causes it, and how long this strange phenomenon lasts. Many facts about him are known to everyone and surprise no one. But there is also interesting information about the eclipse, known to few.

Observing a situation where the fiery disk is completely hidden from view in the entire solar system is possible only on Earth.
Eclipses can be seen anywhere on the planet on average once every 360 years.
The maximum area of overlap of the Sun by the lunar shadow is 80%.
In China, data was found about the first recorded eclipse, which happened in 1050 BC.
The ancient Chinese believed that during an eclipse, a “sun dog” eats the Sun. They began to beat the drums to drive away the celestial predator from the luminary. He should have been scared and returned the stolen goods to the sky.
When a solar eclipse occurs, the lunar shadow moves across the Earth's surface at enormous speeds - up to 2 km per second.
Scientists have calculated that in 600 million years the eclipses will stop completely, because... the satellite will move away from the planet to a great distance.

What is a Solar Eclipse?

A solar eclipse is a natural phenomenon that occurs on Earth when the Moon moves in its orbit between the Earth and the Sun. This occurs on a new moon when the sun and moon are in conjunction with each other. If the Moon were just a little closer to the earth, and its orbit was in the same plane and circular, then we would see eclipses every month. The Moon's orbit is elliptical and tilted relative to the Earth's orbit, so we can only see up to 5 eclipses per year. Depending on the geometry of the Sun, Moon and Earth, the Sun may be completely blocked (obscured), or it may be partially blocked.

During an eclipse, the Moon's shadow (which is divided into two parts: dark umber and light penumbra) moves across the earth's surface. Safety note: Never look directly at the sun during a total solar eclipse. The bright light of the sun can damage your eyes very quickly.

Types of Solar Eclipse

TOTAL SOLAR ECLIPSE

A total solar eclipse occurs when the Moon completely covers the solar disk. During a total solar eclipse, the narrowest part of the path where the sun is completely blocked and the moon casts its dark shadow (called the total umbra) is called the “zone of totality.”

Observers see this path as a darkened sun (often described as a “hole in the sky”) with the ghostly glow of the solar corona traveling into space. The phenomenon is called “Bailey's rosary” and often appears when sunlight filters through valleys on the surface of the Moon. If the sun is active, observers may also see solar prominences, loops, and flares during the eclipse. A total solar eclipse is the only time when it is safe to look directly at the sun. All other solar observations (even partial phases) require special solar filters to avoid damaging your eyes.

A total solar eclipse is not always visible from Earth. In the past, the Moon was too close to the earth and during an eclipse it completely obscured the disk of the Sun. Over time, the lunar orbit has changed by a little more than 2 cm per year and in the current era, the situation is almost ideal. However, the Moon's orbit will continue to expand, and perhaps in 600 million years, total solar eclipses will no longer occur. Instead, future observers will only see partial and annular eclipses.

RING-SHAPED SOLAR ECLIPSE

When the Moon is further in its orbit than usual, it cannot completely cover the disk of the Sun. During such an event, a bright ring of sunlight shines around the moon. This type of eclipse is called an annular eclipse." It comes from the Latin word “annulus”, which means “ring”.

The "ring" period during such an eclipse can last from 5 or 6 minutes to 12 minutes. However, although the Sun is mostly covered by the Moon, when sunlight is bright enough, a ring-shaped glow occurs during which observers will never be able to look at the Sun directly. This event requires eye protection throughout the eclipse.

PARTIAL SOLAR ECLIPSE

A partial solar eclipse occurs when the Earth moves across the lunar penumbra as the moon moves between the Earth and the sun. The Moon does not block the entire solar disk, as seen from Earth. Depending on your location during a partial eclipse, you may see anything from a small piece of the Sun to almost a total eclipse.

To view any eclipse, it is safe to use a filter, or use an indirect viewing method, such as projecting the rays through a telescope onto a white sheet of paper or cardboard. Never look at the sun through a telescope unless it has an appropriate filter. Blindness and severe eye damage can be caused by improper observation techniques.

Facts About Solar EclipsesDepending on the geometry of the Sun, Moon and Earth, there can be from 2 to 5 solar eclipses per year. The totality occurs when the Moon completely covers the sun, so that only the solar corona is visible. A total solar eclipse can occur once every 1- 2 years. This makes them very rare events. If you lived at the North or South Pole, you would only see a partial solar eclipse. People in other parts of the world may experience partial, total, annular and hybrid eclipses. The longest total solar eclipse can last 7.5 minutes. The eclipse path is typically about 100 miles in diameter and can cast a shadow over an area of Earth's surface of about 10,000 miles in length. Almost identical eclipses occur every 18 years and 11 days. This period of 223 synodic months is called saros. During a total solar eclipse, the air temperature can quickly change, immediately becoming colder and the immediate surroundings becoming dark. At the moment of a total solar eclipse, the planets in the sky can be seen as points of light.

It is unlikely that any eyewitness will remain indifferent to such a remarkable phenomenon associated with the Moon as a total solar eclipse. For thousands of years, the black circle engulfing the Sun in broad daylight has inspired people with superstitious fear and awe. To understand the cause of solar eclipses, ancient sky watchers spent centuries painstakingly counting all eclipses, trying to find a pattern and determine the sequence of eclipses. In the end, it turned out that solar eclipses are possible only at the time of new moon, when the Moon passes between the Earth and the Sun.

The Moon, illuminated by the Sun, blocks the path of the sun's rays and casts into space a converging cone of shadow and a diverging cone of penumbra surrounding it, which, under certain circumstances, fall on small areas of the Earth's surface, where observers at that moment see the Sun being covered by a black disk.

Geometry of the onset of a solar eclipse

In the earth's sky, the diameters of the Moon and the Sun almost coincide, which allows the Moon to completely eclipse our daylight star in the sky. This is despite the fact that the diameter of the Sun is almost 400 times the diameter of the Moon. And all because the Sun is about 400 times farther from the Earth than the Moon. This exceptional coincidence, not repeated on any other planet, allows us to observe solar eclipses.

Solar eclipses do not occur at all new moons. The reason for this is that the Moon's path in the sky is tilted about 5° to the Sun's path, the ecliptic. Therefore, eclipses occur only near the intersection points (“nodes”) of their trajectories, where the luminaries are sufficiently close. Depending on the distance to the Moon and the Sun, the size of this zone changes. For solar eclipses, its boundaries are 16°-18° away from the node in each direction. The closer to the node the eclipse occurs, the longer it will last. The longest central eclipses occur at the nodes themselves; in this case, the strip of the main phase passes through the tropical latitudes of the Earth.

Nodes of the lunar orbit and eclipse zones

During new moons that occur far from the lunar nodes, solar eclipses are impossible - the Moon passes above or below the Sun in the sky. Only during new moons near the lunar nodes are eclipses possible.

Sliding along the earth's surface, the end of the moon's shadow draws on it " solar eclipse visibility band". The diameter of the lunar shadow on the earth's surface during a total solar eclipse does not exceed 270 km (most often from 40 to 100 km), and the diameter of the lunar penumbra is close to 6750 km (with an annular eclipse, the width of the central stripe can reach 380 km, and the diameter lunar penumbra - 7340 km). At the same time, the lunar shadow and penumbra on the earth's surface have the form of oval spots, the shape of which depends on the position of the Sun and Moon above the horizon. The lower their height, the more gently the axis of both cones is directed towards the earth's surface, and the more spots of shadow and penumbra are elongated.

The path of the moon's shadow across the earth's surface in 2017

The lunar shadow runs along the Earth from 6,000 to 12,000 km. A solar eclipse begins in the western regions at sunrise and ends in the east at sunset. The total duration of all phases of a solar eclipse on Earth can reach six hours.

TYPES OF SOLAR ECLIPSE

There may be an eclipse complete, ring-shaped And private. The degree to which the Sun is covered by the Moon is called the eclipse phase. It is defined as the ratio of the closed part of the diameter of the solar disk to its entire diameter.

Phase (magnitude) of solar eclipses

Since the Moon’s orbit is not circular, but elliptical, at moments favorable for the onset of eclipses, the lunar disk may appear slightly larger or smaller than the solar one. In the first case, a total eclipse occurs. In the second case, an annular eclipse occurs: a shining ring of the Sun's surface is visible around the dark disk of the Moon.

Total solar eclipse - a phenomenon when the Moon completely covers the Sun in the Earth's sky. If the observer is in the central band of the shadow, he sees a total solar eclipse, in which the Moon completely hides the Sun, the solar corona (the outer layers of the Sun's atmosphere that are not visible in normal light of the Sun) is revealed, the sky darkens, and planets and planets may appear on it. bright stars. For example, Venus and Jupiter will be the easiest to spot due to their brightness.

Diagram of a total solar eclipse

Changes in the appearance of the sky during a total solar eclipse

Observers on either side of the central band of totality can only see a partial solar 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 does not darken, the stars do not appear.

At annular eclipse The Moon passes across the disk of the Sun, but turns out to be smaller in diameter than the Sun, and cannot hide it completely. This happens because the distance of the Moon from the Earth varies from 405 thousand km (apogee) to 363 thousand km (perigee), and the length of the full shadow cone from the Moon is 374 thousand km, so the top of the lunar shadow cone sometimes does not reach the earth’s surface . In this case, for an observer below the apex of the axis of the lunar shadow cone, the solar eclipse will be annular.

Diagram of an annular solar eclipse

Partial solar eclipse is an eclipse in which only the lunar penumbra crosses the earth's surface. This occurs when the Moon's shadow passes above or below the Earth's polar regions, leaving only the lunar penumbra on our planet.

Scheme of a partial solar eclipse (without the central eclipse band)

During partial eclipses, the weakening of sunlight is not noticeable (with the exception of eclipses with a large phase), and therefore the phases of the eclipse can only be observed through a dark filter.

On the use of protective filters when observing solar eclipses in the material:

DURATION AND FREQUENCY OF SOLAR ECLIPSE ON EARTH

The maximum duration of a total solar eclipse is 7.5 minutes. This is possible from the end of June to mid-July, when the diameter of the solar disk in the sky is minimal (the Sun passes the aphelion of its orbit), and the Moon is at its shortest distance from the Earth (perihelion). The previous long solar eclipse lasted 7 minutes and 7 seconds (Southeast Asia, June 20, 1955). And the shortest solar eclipse (1 second) occurred on October 3, 1986 (North Atlantic Ocean). The nearest eclipse, lasting 7 minutes 29 seconds, will occur on July 16, 2186.

The longest duration of the annular phase cannot exceed 12.3 minutes, and the duration of a partial eclipse can reach approximately 3.5 hours. The vast majority of eclipses last up to 2.5 hours (partial phases), and their total or annular phase usually does not exceed 2-3 minutes.

Every year there are two eras of eclipses, the interval between which is 177 - 178 days. One eclipse zone occupies about 34°; the Sun spends about 34 days in each zone. And the period between new moons is 29.5 days (synodic month), which means the Moon must necessarily pass through the eclipse zone while the Sun is there, and can visit it twice during this period. Therefore, with each passage of the Sun through the eclipse zone (once every six months), one eclipse should occur, but two can occur. Thus, from 2 to 5 solar eclipses can occur on Earth per year. Over the course of six months (about 183 days), eclipse epochs shift five days ahead, to earlier calendar dates, and gradually move to different seasons of the year - from summer and winter to spring and autumn, again to winter and summer, etc.

Five solar eclipses per year are possible, if the first pair of partial solar eclipses in one zone occurs in early January and February, then the next pair of partial eclipses in another zone may occur at the very beginning of July and August, and from the next probable pair of partial eclipses only one is possible at the very end of December, and the second will occur in January of the next calendar year. Thus, the largest number of solar eclipses in one calendar year does not exceed five, and all of them are necessarily partial with small phases.

Central visibility bands of total and annular eclipses from 1981 to 2100

Most often, there are 2-3 solar eclipses annually, and one of them is often total or annular. Four partial eclipses last occurred in 2000 and 2011. The next years when four partial eclipses are expected are 2029 and 2047. The last time there were five partial solar eclipses (all of which are necessarily partial with small phases) in one calendar year was in 1935. The next time such a phenomenon is expected is in 2206.

The pattern of recurrence of solar eclipses is very complex. Each solar eclipse repeats itself over a period of time of 6585.3 days or 18 years 11.3 days (or 10.3 days if the period contains five leap years), called a saros. During Saros, on average, 42-43 solar eclipses occur, of which 14 are total, 13-14 annular and 15 partial. However, after the end of Saros, each eclipse is repeated under different conditions, since Saros does not contain a whole number of days, and for an excess of about 0.3 days (over 6585 days), the Earth will rotate around its axis by approximately 120° and therefore the lunar shadow will run across the Earth’s surface the same 120° to the west than 18 years ago, and the Sun and Moon will be at slightly different distances from the lunar node. On average, every hundred years there are 237 solar eclipses on Earth, of which 160 are partial, 63 are total, 14 are annular.

In one locality, total solar eclipses occur on average once every 360 years, with rare exceptions. Partial solar eclipses occur in each area much more often - on average every 2-3 years, but since during solar eclipses with a small phase the sunlight almost does not weaken, they are not of great interest and usually go unnoticed.

Materials used in preparing this article:

Surely, almost everyone has heard about solar eclipses, and sometimes personally observed this phenomenon, which terrified people several centuries ago. And although astronomers have uncovered the mystery of this phenomenon, there are many interesting facts about solar eclipses, and these facts may surprise even those who were diligent students in astronomy lessons.

1. Shadow of the Moon

A solar eclipse occurs when the Moon passes in front of the Sun and casts a shadow on the Earth. This is due to the fact that the distance between the Sun and the Earth is approximately 400 times greater than the distance of the Moon from the Sun. The diameter of the Sun is also about 400 times larger than that of the Moon. Thanks to this, the Sun and Moon are the same size when observed from Earth. When the Moon passes in front of the Sun, it blocks its light from being seen from Earth.

2. Partial, circular and general

There are three different types of solar eclipses: partial, annular and total. A partial solar eclipse is when the Moon does not "perfectly align" with the Sun. An annular solar eclipse is when the Moon and Sun are on the same line, but either the Moon is currently further away from the Earth, or the Earth is closer to the Sun. In this situation, the Moon's apparent size is smaller than that of the Sun, resulting in a bright ring surrounding the dark Moon. A total eclipse is when the Moon completely covers the Sun.

3. Stars during the day

Stars appear in the daytime sky. Because an eclipse causes the day to become darker, planets and stars normally hidden by the sun's light will be visible in the sky. First of all, you should look for Mars, Mercury, Jupiter and Venus.

4. Eye protection

You should not look at the eclipse without eye protection. Looking directly at the sun without protecting your eyes is very dangerous. It can even lead to blindness.

5. Only on a new moon

A solar eclipse occurs only during the new moon. This happens because the Moon must be between the Sun and the Earth for an eclipse to occur. The only lunar phase when this happens is the new moon.

6. 5° exception

Although eclipses occur during new moons, they do not occur during every new moon. This is because the Moon's orbit is tilted 5 degrees relative to the Earth's orbit around the Sun. Eclipses occur only when the “paths” of the Earth, Sun and Moon intersect (this intersection is called a “node”). Usually the Sun is above or below the “node”, which is why an eclipse does not occur.

7. Glare, silence and drop in temperature

Strange things happen during an eclipse. As the eclipse approaches, you may encounter strange phenomena. For example, throughout the horizon you can see areas that are lighter than the sky around the sun, shadows that look different. Birds also stop chirping, and temperatures drop by about 1-5 degrees.

8. "Oracle Bones"

China has released the first known recordings of solar eclipses. This data about solar eclipses was imprinted on pieces of bone, which were later called “Oracle Bones”. They date back to around 1050 BC.

9. No moon - no eclipses

In about a million years, solar eclipses will not be noticeable. This will happen because the Moon is slowly moving away from the Earth.

10. Lucky Campbell

Canadian astronomer and famous eclipse hunter John Wood Campbell traveled the world for 50 years trying to see 12 different eclipses. And every time he faced a cloudy sky.

On March 20 this year, there will be a total solar eclipse that will block up to 90 percent of the sun. The eclipse will be the largest event in the last 16 years. On this day, the Moon passes directly in front of the Sun, casting a shadow on the Earth. A solar eclipse could cause temporary power outages across Europe. The eclipse will occur on the afternoon of Friday 20 March and will begin at 7:41 UTC (Universal Time) and end at 11:50 UTC.

· Start of solar eclipse: 12:13 Moscow time

· Maximum phase of solar eclipse: 13:20 Moscow time

· End of solar eclipse: 14:27 Moscow time

Maximum solar obscuration: 58 percent

A total eclipse will be observed in eastern Greenland, Iceland, the Svalbard archipelago and the Faroe Islands. Russia, Europe, northern and eastern Africa and northern and eastern Asia will experience a partial solar eclipse.

The last time a total solar eclipse of this magnitude occurred was on August 11, 1999, and the next one will take place in 2026. In addition, the eclipse could disrupt solar power supplies and lead to power outages.

Remember not to look directly at the Sun during sun exposure, as this may cause permanent eye damage. To observe, you need to use special solar filters.

The eclipse falls on the equinox and new moon, and the Moon will reach lunar perigee, the closest point to Earth in its orbit. The spring equinox occurs on March 20, 2015 at 22:45 UTC (March 21 1:45 Moscow time). It represents the moment when the Sun crosses the celestial equator. On the day of the equinox, the length of night and day is the same and is 12 hours.

March's new moon will be a supermoon, which, although not visible, will have a larger than normal impact on Earth's oceans. An eclipse occurs when a celestial body, such as the Moon or a planet, passes into the shadow of another body. There are two types of eclipses that can be observed on Earth: solar and lunar.

During a solar eclipse, the Moon's orbit passes between the Sun and the Earth. When this happens, the Moon blocks the sun's light and casts a shadow on the Earth.

There are several types of solar eclipse:

Full - it is visible in certain areas of the Earth that are in the center of the lunar shadow falling on the Earth. The Sun, Moon and Earth are in a straight line.

Partial - This eclipse occurs when the Sun, Moon and Earth are not exactly in line and observers are positioned in the penumbra.

Annular - occurs when the Moon is at its farthest point from the Earth. As a result, it does not completely block the solar disk, but appears as a dark disk around which a bright ring is visible.