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.
Recently, astronomy has ceased to be a compulsory subject in school; hopes are pinned on this publication for the possibility of filling the forced gaps in education with the help of the Internet...
First of all, let’s turn to the Great Soviet Encyclopedia to take advantage of the time-tested and undoubtedly outstanding scientists definition of the subject of our conversation: “An eclipse is an astronomical phenomenon in which the Sun, Moon, planet, satellite of a planet or star ceases to be visible in whole or in part to an earthly observer.
Eclipses occur due to the fact that either one celestial body covers another, or the shadow of one non-self-luminous body falls on another similar body. An eclipse of the Sun is observed when it is covered (overshadowed) by the Moon."Solar eclipses always occur on New Moon.
A solar eclipse is a unique phenomenon every time.
What types of eclipses are there?
We are so used to our moon that we don’t even realize how lucky we are with it! And we were lucky to have her twice. First, our Moon is not some shapeless boulder like Phobos or Deimos, but a neat, round mini-planet! Second: The Moon is now far enough away from the Earth and there are no daily earthquakes and huge waves, once in the past caused by the tidal forces of the Moon (in our time, the Moon is moving away from the Earth at a speed of 4 cm per year - in earlier eras this happened faster). The Moon is now so far away that its apparent angular size is close to that of the even more distant Sun. And once upon a time the Moon was so close to the Earth that solar eclipses occurred every new moon, although at that time there was no one to look at them...
Each solar eclipse is unique in its own way; exactly how the eclipse will look for an observer on earth is determined by 3 factors (in addition to weather): the angular diameters (dimensions) of the Sun visible from the observation point α and the moon β and the trajectory of the Moon relative to the Sun and stars (Fig. 2).
Rice. 2. The angular diameters of the Sun visible from the Earth's surface ( α ) and Moon ( β ), the trajectory of the Moon’s movement across the starry sky (dotted line).
Due to the fact that the Moon and the Earth move in elliptical orbits (the Moon is sometimes closer and sometimes further from the Earth, and the Earth, in turn, is sometimes closer and sometimes further from the Sun), the apparent angular diameter of the Moon, depending on its orbital position, can vary from 29 .43" to 33.3" (arcminutes), and the apparent angular diameter of the Sun is from 31.6" to 32.7". Moreover, their average apparent diameters, respectively, are for the Moon: 31"05" and for the Sun: 31"59".
Depending on whether the visible trajectory of the Moon passes through the center of the Sun, or intersects its visible region in an arbitrary place, as well as various combinations of the visible angular sizes of the Moon and the Sun, three types of solar eclipses are traditionally distinguished: partial, total and annular eclipses .
Partial solar eclipse
If the observed trajectory of the Moon does not pass through the center of the Sun, then the Moon, as a rule, cannot completely obscure the Sun (Fig. 3) - an eclipse in which the Moon covers the Sun is not completely called partial (partial from the word “part” with the meaning “partial” eclipse"). Such an eclipse can occur for any possible combination of the apparent angular diameters of the Moon and the Sun.
The majority of solar eclipses occurring on Earth are partial eclipses (approximately 68%).
Total solar eclipse
If at any point on the Earth's surface observers can see that the Moon completely covers the Sun, then such an eclipse is called a total solar eclipse. Such an eclipse occurs when the apparent path of the Moon passes through the center of the Sun or very close to it and at the same time the apparent diameter of the Moon β must be greater than or at least equal to the apparent diameter of the Sun α (Fig. 4).
Rice. 4. Total solar eclipse, March 20, 2015 in 12:46 observed near the North Pole.
A total solar eclipse can be observed within very small areas of the earth's surface, as a rule, it is a strip up to 270 km wide, outlined by the shadow of the Moon - observers in areas adjacent to the shadowed areas see only a partial solar eclipse (Figure 5).
Rice. 5. Total solar eclipse, the shadow of the Moon on the surface of the Earth, the dark dotted line indicates the trajectory of the shadow area
For each specific area, a total solar eclipse is very rare. In Moscow, for example, the last total solar eclipse occurred in August 1887 (08/19/1887), and the next one is expected on 10/16/2126. So, if you sit in one place for a long time, you may never see a total solar eclipse in your life ( however, in August 1887, Muscovites still did not see it due to bad weather). Therefore: “If you want to survive an event, do everything possible to make it happen!” /Slogan of Enthusiasts/
Thank God, in general, on the surface of the Earth, total eclipses do not occur very rarely, on average once every year and a half and account for almost 27% of all eclipse variants.
Annular solar eclipse
If the trajectory of the Moon passes near the center of the Sun, but the apparent angular diameter of the Moon is less than that of the Sun β < α , then at the moment the centers align, the Moon cannot completely obscure the Sun and a glow in the form of a ring is created around it, such an eclipse is called annular (Fig. 6), but in oral speech, which traditionally strives to express the meaning as briefly as possible, the expression annular eclipse has been established, i.e. . "Annular solar eclipse" is a term, but "annular eclipse" is just jargon for now...
Rice. 6. An annular solar eclipse, someday...
Annular (annular) solar eclipses are currently the rarest type of eclipses, accounting for only 5%. But, as we know, the Moon is gradually moving away from the Earth and annular eclipses will occur more and more often.
Why solar eclipses happen so rarely
The main reason that solar eclipses in our time do not occur every new moon is that the plane of the Moon’s orbit does not coincide with the plane of the ecliptic (the plane of the Earth’s orbit) and is inclined to it at an angle of 5.145 degrees (Fig. 7, item 1). In this figure, as well as in all others, the sizes of the angles and the ratio of the scales of objects are exaggerated for clarity of the images.
Rice. 7.
Work on the article "Solar Eclipses" continues.
Sergey Ov(Seosnews9)
Solar eclipses of 2019:
January 2019 - Partial solar eclipse
;
July 2019 - Total solar eclipse;
December 2019 -(observed in Russia)
06.01.2019 04:28
- New Moon.
This new moon will happenpartial solar eclipse
January 6, 2019 at 04:41 MSK, eclipse it will be possible to observe in eastern Mongolia, northeastern China, Korea and Japan, in Russia - in the south of Eastern Siberia, the Far East, Kamchatka, the Kuril Islands and Sakhalin.
02.07.2019 22:16
- New Moon.
This new moon will happen total solar eclipse
, the maximum phase of the eclipse will begin July 2, 2019 at 10:26 pm MSK, a partial eclipse of the Sun can only be observed in the south Pacific Ocean, Central and South America (Chile, Argentina), alas: will not be observed in Russia...
26.12.2019 08:13
- New Moon.
This new moon will make the inhabitants of the Earth happy with the third solar eclipse of the year - it will be annular solar eclipse
(annular), the maximum phase of the eclipse will occur December 26, 2019 05:18:53 MSK, an annular eclipse can be observed in the east of the Arabian Peninsula, southern India, Sri Lanka, Sumatra, Malaysia and Indonesia, and partial in Central and Southeast Asia, Australia and western Oceania , in Russia the eclipse will be observed in Transbaikalia and Primorye
.
2018:
February 2018 - Partial solar eclipse;
July 2018 - Partial solar eclipse;
August 2018 - Partial solar eclipse
(observed in Russia)
16.02.2018 00:05
- New Moon
This new moon will happen partial solar eclipse
, the maximum phase of the eclipse will begin 02/15/2018 at 23:52 MSK, a partial eclipse of the Sun can only be observed in Antarctica and southern South America (Chile, Argentina) - summary: V Russia will not be observed.
13.07.2018 05:48
- New Moon (
, (super new moon) - a variant translation from the English word "supermoon", another - "Super Moon". On a new moon, the Moon is usually not visible, but in such cases there are very strong tides, maybe a better translation would be: “Strong Moon”?)
In addition, on this new moon there will be partial solar eclipse
, the maximum phase of the eclipse will begin 07/13/2018 at 06:02 MSK. The eclipse can be observed, alas, only in Antarctica on the Budd Coast, the southernmost part of Australia, Tasmania or in the Indian Ocean between Antarctica and Australia - the eclipse will not be observed in Russia
.
11.08.2018 12:58
- New moon(
, Strong Moon)
On this new moon it will also happenpartial solar eclipse
, the maximum phase of the eclipse will begin August 11, 2018 at 12:47 MSK, the eclipse can be observed in the north of Canada, Greenland in the Scandinavian countries, in Russia - in the northern and middle latitudes of Central Russia, throughout Siberia and the Far East
, northeastern Kazakhstan, Mongolia and China .
2017: February 2017 - Annular solar eclipse; August 2017 - Total solar eclipse
26 February 2017 17:58
On this winter new moon there will be annular solar eclipse
. The maximum phase of the eclipse will begin February 26, 2017 at 17:54 MSK
. An annular eclipse of the Sun can be observed in the south of Argentina and Chile, southwest Angola, and private in southern South America, Antarctica, western and southern Africa - will not be observed in Russia.
21 August 2017 21:30- astronomical new moon.
On this summer new moon there will be total solar eclipse
. The maximum phase of the eclipse will begin August 21, 2017 at 21:26 MSK.
A total eclipse of the Sun can be observed, alas, only in North America in the United States, private in Russia
- in Chukotka (the Moon will barely touch the Sun); in other countries- in the USA and Canada, Greenland, Iceland, Ireland and the UK, Portugal (at sunset), Mexico, Central America, Ecuador, Peru, Colombia, Venezuela, Guyana, Suriname, Guinea and Brazil.
March 2016 - Total Solar Eclipse + Supermoon
09 March 2016 04:54 Moscow time - astronomical new moon;
This new moon will happen total solar eclipse, the maximum phase of the eclipse will begin March 09, 2016 at 04:58 MSK, a total solar eclipse will be observed on the islands of Sumatra, Kalimantan, Sulawesi and Halmahera, private in Russia- in Primorye, Sakhalin, Kuril Islands and Kamchatka; in other countries in India, China, Thailand, Laos and Cambodia, Malaysia, Indonesia, Papua New Guinea, Philippines, USA and Canada (Alaska)
;
01.09.2016 12:03
- astronomical new moon;
This new moon will happen annular solar eclipse, the maximum phase of the eclipse will begin September 01, 2016 at 12:08 MSK
, An annular eclipse can be observed, alas, only in central Africa and Madagascar, and a partial eclipse in all African countries, in Saudi Arabia, Yemen and in the Indian Ocean
March 2015 - Total Solar Eclipse + Supermoon
March 20, 2015 12:36 Moscow time - astronomical new moon; ;
On this new moon there will be a total solar eclipse, the maximum phase of the eclipse will occur on March 20, 2015 at 12:46:47 MSK, total eclipse of the sun can be observed in the Faroe Islands, Spitsbergen and the North Pole, partial eclipse in Russia- throughout the European part and Western Siberia; as well as in Greenland, Europe and Central Asia.
;
* Eclipses, eclipse = Z.
Z. - astronomical phenomena, which consist in the fact that the Sun, Moon, planet, satellite of a planet, or star ceases to be visible in whole or in part to an earthly observer. Shadows occur due to the fact that either one celestial body covers another, or the shadow of one non-self-luminous body falls on another similar body. Thus, the Earth of the Sun is observed when it is covered by the Moon; W. Moon - when the shadow of the Earth falls on it; Z. satellites of planets - when they fall into the shadow of a planet; Z. in systems of double stars - when one star covers the other. Zoning also includes the passage of a satellite's shadow across the planet's disk, the Moon's occultation of stars and planets (the so-called occultation (See Occultation)), the passage of the inner planets Mercury and Venus across the solar disk, and the passage of satellites across the planet's disk. With the beginning of flights of manned spacecraft, it became possible to observe the Earth from the Sun from these ships (see illustration). Of greatest interest are the rays of the Sun and the Moon, associated with the movement of the Moon around the Earth.
Great Soviet Encyclopedia, 3rd ed. 1969 - 1978
For a solar eclipse to occur, the Earth, Moon and Sun must line up, which only happens during new moons. Due to the Moon's orbital movement at a speed of about 1 km/s, its shadow moves relative to the Earth at approximately the same speed. The maximum time during which the Moon's shadow (the area of total eclipse of the Sun) slides across the Earth is about 3.5 hours, and the penumbra (the area of partial eclipse) lingers on the Earth for about 5.5 hours. The maximum size of the shadow on the Earth's surface is about 270 km . Residents who find themselves in the path of the shadow observe a total eclipse of the Sun. The duration of this phenomenon depends on the latitude of the area, since the Earth's surface rotates in the same direction - from west to east, where the lunar shadow moves, with a maximum speed at the equator of 0.46 km / s. Therefore, near the equator, total eclipses can last up to 7 minutes 40 seconds, and at a latitude of 45° - up to 6.5 minutes. At every point on Earth, a total eclipse occurs on average once every 360 years.
By happy coincidence, the angular diameters of the Sun and Moon are almost the same: they are close to 0.5°. If at the moment of a solar eclipse the Moon passes perigee (the point of its orbit closest to the Earth), then it completely eclipses the Sun; at the apogee (the most distant point of the orbit), the angular size of its disk is less than the solar one, so an annular eclipse occurs.
Observable phenomena.
During partial eclipses of the Sun, the overall flow of its light is weakened slightly, incl. many people do not even notice this phenomenon unless they have been warned in advance. The part of the solar disk not covered by the Moon shines in the form of a “month”; this is easy to see if you look at the Sun through a thick filter, such as a piece of exposed photographic film.
Before the start of a total eclipse, the brightness decreases noticeably and the narrow crescent of the Sun can be observed without a filter. The crescent tapers rapidly, and when it occupies a very small portion of the arc, it is called a “diamond ring.” At the last moment, this area is divided into a chain of bright spots called “Bailey's rosary” - these are the rays of the Sun shining through the unevenness of the lunar edge (lunar valleys). Suddenly darkness falls and a snow-white solar corona appears. Its brightness is half a million times lower than that of the Sun's disk, and quickly decreases towards the edges, but when darkness sets in, individual rays of the corona can be traced to a distance of several degrees. A pinkish strip of the chromosphere is visible along the edge of the lunar disk. Sometimes bright pink tongues of prominences stretching above the chromosphere are visible. Here and there stars are visible in the sky. A few minutes later, the “Bailey’s rosary” and the “diamond ring” appear on the opposite side of the solar disk - the total eclipse is over and the corona has faded in the rays of the Sun.
Annular eclipse.
The average length of the lunar shadow is 373 thousand km, while the average distance from the Earth to the Moon is 385 thousand km. Therefore, in most eclipses, the lunar shadow does not reach the earth's surface. At the same time, the Moon does not completely cover the solar disk, but leaves a thin rim visible. With such an annular eclipse, the bright rim of the Sun makes it impossible to see either the corona or stars near the Sun. Therefore, annular eclipses are not of great scientific interest.
Lunar eclipses.
For an eclipse of the Moon, the Sun, Earth and Moon must also be located approximately on the same straight line. If the Moon passes through the Earth's penumbra, its brightness is weakened slightly. Penumbral eclipses are unattractive to astronomers and are rarely discussed. When the Moon enters the Earth's shadow, a fairly clear dark area moves onto its surface, which turns red and darkens greatly, but still remains visible: it is illuminated by the sun's rays scattered and refracted in the earth's atmosphere, and red rays pass through the air better than blue ones ( for the same reason the Sun is red at the horizon). The brightness of the Moon during a total eclipse depends greatly on the cloudiness of the Earth's atmosphere.
Scientific interest in lunar eclipses mainly stems from the ability to measure the rate at which its surface temperature drops after an abrupt cessation of solar heating. The rapid drop in temperature indicates that the top layer of lunar soil is a poor conductor of heat.
Geometry of eclipses.
The Moon's path in the sky is tilted approximately 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. The apparent displacement of the Moon when observed from different points on the Earth (diurnal parallax), as well as the finite size of the Sun and Moon, make eclipses possible in a certain zone near the nodes of their orbits. Depending on the distance to the Moon and the Sun, the size of this zone changes. For solar eclipses, its boundaries are spaced from the node in each direction by 15.5–18.4°, and for lunar eclipses – by 9.5–12.2°.
Solar eclipses.
The Sun makes a 360° revolution along the ecliptic in 365 1/4 days; since the eclipse zone occupies about 34°, the Sun spends about 34 days in this zone. But the period between new moons is 29 1/2 days, which means that the Moon must necessarily pass through the eclipse zone while the Sun is there, but it 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.
Lunar eclipses.
The Earth's shadow passes through the lunar eclipse zone on average every 22 days. During this period, no more than one lunar eclipse can occur, since 29 1/2 days pass between full moons. An eclipse may not happen at all if one full moon was on the eve of the shadow entering the zone, and the next - immediately after it left the zone.
Although lunar eclipses occur less frequently than solar eclipses, we see total eclipses of the Moon much more often than of the Sun. The fact is that the Moon, covered by the earth's shadow, can be observed by all inhabitants of the night hemisphere of the Earth, while to observe a total solar eclipse you need to fall into a narrow strip of the lunar shadow.
Recurrence of eclipses.
The period between two successive passages of the Sun through the ascending node of the lunar orbit is called the draconic year (remember the legend of the dragon devouring the Sun). During this period, at least two solar eclipses should occur - one each near the ascending and descending nodes; but there may not be a single lunar one. A maximum of one lunar and one solar eclipse can occur at each node - six in total.
Since the rotation of the lunar orbit causes the nodes to move towards the Sun, the draconic year lasts only 346.6 days. Thus, if the first eclipse of the year occurred before January 19, then the seventh eclipse may also occur before the end of the calendar year. The nearest such situation will be in 2094.
Saros.
E. Halley discovered that eclipses repeat cyclically every 223 lunar months. He called this period "Saros", mistakenly believing that this was the name given to it by the Babylonians, who were undoubtedly familiar with this period. Ancient Greek astronomers were familiar with a triple saros lasting 54 years, which they called exeligmos.
In 19 draconic years (6585.78 days), almost exactly 224 new moons (6585.32 days) occur. Therefore, at any moment, the phases of the Moon are related to its position relative to the nodes in the same way as it was 18 years and 11 1/3 days ago (or 18 years and 10 1/3 days, depending on the number of leap years). Since Saros differs by only 11 1/3 days from the number of whole years, the eclipses of the next cycle occur mainly against the background of the same constellations as the previous one.
The difference between 223 lunar months by 1/3 of a day from the whole number of solar days leads to the fact that during the eclipses of the next Saros, the Earth is shifted by 1/3 of a revolution to the east, and the corresponding eclipses are observed 120° to the west in longitude. But after 3 saros the situation repeats itself much more accurately. Since the relationship between the draconic year and the lunar month is not entirely simple, successive eclipses in Saros are shifted north or south depending on whether they occur in the ascending or descending node. Finally, the lunar shadow slides over the earth's poles, and this sequence of eclipses ends. During one 18-year saros, between 70 and 85 eclipses occur; There are usually 43 solar and 28 lunar eclipses.
Eclipse tables.
Circumstances of all eclipses since 1207 BC. to 2161 AD were calculated by T. von Oppolzer and published in his Canon of Eclipses(Canon der Finsternisse, 1887). In table 2 uses data from this classic work; table 1 taken from Canon of solar eclipses(1966) J. Meesa, C. Grosien and V. Vanderlin. It marks all solar eclipses from 1988 to 2028, except for partial ones. Visibility areas are listed in order of shadow traversal. To find out the exact location of the total eclipse stripe, you need to refer to special publications.
| Table 1. TOTAL AND ANnULAR ECLIPSE OF THE SUN | |||
| date | Type | Continue Duration (minutes) |
Area of visibility |
| 1988, March 18 | P | 4 | Sumatra, Philippines, north. Pacific Ocean |
| 1988, September 11 | TO | 7 | Indian Ocean |
| 1990, January 26 | TO | 2 | Indian Ocean |
| 1990, July 22 | P | 3 | Finland, Siberia, northern Pacific Ocean |
| 1991, January 15/16 | TO | 8 | South Pacific Ocean |
| 1991, July 11 | P | 7 | Hawaii, Central America, Brazil |
| 1992, January 4/5 | TO | 12 | Center. Pacific Ocean, California |
| 1992, June 30 | P | 5 | South Atlantic |
| 1994, May 10 | TO | 6 | USA, northern Atlantica, Morocco |
| 1994, November 3 | P | 4 | Pacific Ocean, Center. and South America, Atlantic |
| 1995, April 29 | TO | 7 | Pacific Ocean, Peru, Brazil |
| 1995, October 24 | P | 2 | Iran, India, southeast. Asia, Pacific |
| 1997, March 9 | P | 3 | Mongolia, Siberia, Arctic |
| 1998, February 26 | P | 4 | Pacific Ocean, Colombia, north. Atlantic |
| 1998, August 22 | TO | 3 | Sumatra, Borneo, south. Pacific Ocean |
| 1999, February 16 | TO | 1 | South Indian Ocean, Australia |
| 1999, August 11 | P | 2 | North Atlantic, center. Europe, India |
| 2001, June 21 | P | 5 | South Atlantic, south Africa |
| 2001, December 14 | TO | 4 | Pacific Ocean, Nicaragua |
| 2002, June 10/11 | TO | 1 | North Pacific Ocean |
| 2002, December 4 | P | 2 | North Africa, Indian Ocean, Australia |
| 2003, May 31 | TO | 4 | Iceland |
| 2003, November 23 | P | 2 | Antarctic |
| 2005, April 8 | KP | 1 | North Pacific Ocean, Panama |
| 2005, October 3 | TO | 5 | Indian Ocean, north. Africa, Spain |
| 2006, March 29 | P | 4 | North Africa, Türkiye, Russia |
| 2006, September 22 | TO | 7 | Brazil, northern Atlantic |
| 2008, February 7 | TO | 2 | Antarctica, south Pacific Ocean |
| 2008, August 1 | P | 2 | Arctic, Russia, China |
| 2009, January 26 | TO | 8 | South Indian Ocean, Borneo |
| 2009, July 22 | P | 7 | India, China, Pacific Ocean |
| 2010, January 15 | TO | 11 | Center. Africa, Indian Ocean, China |
| 2010, July 11 | P | 5 | South Pacific Ocean, China |
| 2012, May 20/21 | TO | 6 | Japan, northern Pacific Ocean, USA |
| 2012, November 13 | P | 4 | North Australia, south Pacific Ocean |
| 2013, May 9/10 | TO | 6 | Australia, center. Pacific Ocean |
| 2013, November 3 | P | 2 | Atlantic, Center. Africa |
| 2015, March 20 | P | 3 | North Atlantic, Arctic |
| 2016, March 9 | P | 4 | Sumatra, Borneo, north. Pacific Ocean |
| 2016, September 1 | TO | 3 | Center. Africa, Madagascar, Indian Ocean |
| 2017, February 26 | TO | 1 | Pacific Ocean, Argentina, Atlantic, Africa |
| 2017, August 21 | P | 3 | Pacific Ocean, USA, Atlantic |
| 2019, July 2 | P | 5 | South Pacific Ocean, Chile, Argentina |
| 2019, December 26 | TO | 4 | Arabia Peninsula, India, Borneo, Pacific Ocean |
| 2020, June 21 | TO | 1 | Center. Africa, Arabia Peninsula, China |
| 2020, December 14 | P | 2 | Pacific Ocean, Chile, Argentina, Atlantic |
| 2021, June 10 | TO | 4 | Arctic, Siberia |
| 2021, December 4 | P | 2 | Antarctic |
| 2023, April 20 | P | 1 | Indian Ocean, Indonesia, Pacific Ocean |
| 2023, October 14 | TO | 5 | USA, Yucatan Peninsula, Brazil |
| 2024, April 8 | P | 4 | Pacific Ocean, Mexico, USA |
| 2024, October 2 | TO | 7 | |
| 2026, February 17 | TO | 2 | Antarctic |
| 2026, August 12 | P | 2 | Greenland, Antarctica, Spain |
| 2027, February 6 | TO | 8 | Pacific Ocean, Argentina, Atlantic |
| 2027, August 2 | P | 6 | North Africa, Indian Ocean |
| 2028, January 26 | TO | 10 | Pacific, Brazil, Atlantic, Spain |
| 2028, July 22 | P | 5 | Pacific Ocean, Australia, New Zealand |
| Table 2. LUNAR ECLIPSE | |||
| date | Duration (minutes) | The place where the moon is at its zenith | |
| General | Full phase | ||
| 1988, August 27 | 122 | – | Samoa |
| 1989, February 20 | 212 | 76 | Philippines |
| 1989, August 17 | 220 | 98 | Center. Brazil |
| 1990, February 9 | 204 | 46 | South India |
| 1990, August 6 | 174 | – | North-East Australia |
| 1991, December 21 | 70 | – | Hawaii |
| 1992, June 15 | 174 | – | North China |
| 1992, December 9 | 212 | 74 | South Algeria |
| 1993, June 4 | 220 | 98 | O. New Caledonia |
| 1993, November 29 | 206 | 50 | Mexico City |
| 1994, May 25 | 116 | – | South Brazil |
| 1995, April 15 | 78 | – | Fiji |
| 1996, April 4 | 216 | 84 | Gulf of Guinea |
| 1996, September 27 | 212 | 72 | Guiana |
| 1997, March 24 | 194 | – | North-west Brazil |
| 1997, September 16 | 210 | 66 | Maldives |
| 1999, July 28 | 142 | – | Samoa |
| 2000, January 21 | 214 | 84 | Puerto Rico |
| 2000, July 16 | 224 | 102 | North-East Australia |
| 2001, January 9 | 210 | 66 | Muscat (Oman) |
| 2001, July 5 | 154 | – | North and center. Australia |
| 2003, May 16 | 208 | 58 | South center. Brazil |
| 2003, November 9 | 200 | 24 | Cape Verde Islands |
| 2004, May 4 | 214 | 80 | Madagascar |
| 2004, October 28 | 214 | 80 | Barbados |
| 2005, October 17 | 66 | – | Marshall Islands |
| THE END OF SAROS THAT STARTED IN 1988 | |||
| 2006, September 7 | 98 | – | Maldives |
| 2007, March 3 | 210 | 70 | Nigeria |
| 2007, August 28 | 220 | 92 | Samoa |
| 2008, February 21 | 206 | 52 | Center. Atlantic |
| 2008, August 16 | 186 | – | Center. Atlantic |
| 2009, December 31 | 66 | – | Pakistan |
| 2010, June 26 | 156 | – | Tonga Islands |
| 2010, December 21 | 212 | 74 | Gulf of California |
| 2011, June 15 | 224 | 102 | Reunion Island |
| 2011, December 10 | 206 | 56 | East New Guinea |
| 2012, June 4 | 140 | – | Cook Islands |
| 2013, April 25 | 36 | – | Madagascar |
| 2014, April 15 | 212 | 76 | (117° west, 9° south) |
| 2014, October 8 | 208 | 62 | Palmyra Atoll |
| 2015, April 4 | 200 | 24 | Ellis Islands |
| 2015, September 28 | 214 | 78 | Northeast Brazil |
| 2017, August 7 | 114 | – | (87° east, 16° south) |
| 2018, January 31 | 214 | 82 | Enewetak Atoll |
| 2018, July 27 | 220 | 98 | Mauritius Island |
| 2019, January 21 | 210 | 68 | Cuba |
| 2019, July 16 | 172 | – | Mozambique |
| 2021, May 26 | 200 | 24 | Tonga Islands |
| 2021, November 19 | 198 | – | (139° west, 19° north) |
| 2022, May 16 | 218 | 88 | Bolivia |
| 2022, November 8 | 216 | 84 | Johnston Atoll |
| 2023, October 28 | 86 | – | South Arabia |
| THE END OF SAROS THAT STARTED IN 2006 | |||
| 2024, September 18 | 70 | – | Northeast Brazil |
| 2025, March 14 | 208 | 62 | Galapagos Islands |
| 2025, September 7 | 216 | 84 | (87° east, 6° south) |
| 2026, March 3 | 208 | 62 | Palmyra Atoll |
| 2026, August 28 | 194 | – | Zap. Brazil |
| 2028, January 12 | 60 | – | Puerto Rico |
| 2028, July 6 | 136 | – | (86° east, 22° south) |
| 2028, December 31 | 212 | 72 | South China |
Unlike a solar eclipse, a lunar eclipse is simultaneously observed from the entire hemisphere of the Earth. Therefore, in Table. 2 shows the central point of this hemisphere (always lying between the tropics), where the moon is at its zenith in the middle of the eclipse. Having found this point on the globe, you can easily determine the “hemisphere of visibility”. In its western part, the eclipse is observed in the evening, and in the eastern part - in the morning.
Eclipses in the past.
The earliest record of an eclipse is found in ancient Chinese documents, but the paucity of information makes it impossible to establish its exact date. Based on the records of eclipses, it is possible to compile a Chinese chronology starting from the 8th century. BC. The first substantiated date in Chinese history is an eclipse on November 30, 735 BC. This event is sometimes mistakenly associated with the eclipse of September 6, 776 BC, which was poorly visible in China.
The first eclipse, information about which still retains scientific value, occurred on June 15, 763 BC. in Assyria. It probably became the reason for the prophecy ( Amos, 8:9 ). Based on this and other ancient eclipses, astronomers have found that the length of the day is increasing by 0.001 seconds per century due to the slowing of the Earth's rotation.
According to Herodotus, the eclipse of May 28, 585 BC. so frightened the Medes and Lydians that they stopped the battle and concluded a truce after a five-year war. Herodotus reports that Thales of Miletus predicted the year in which this eclipse was to occur. It is very unlikely that Thales could have accurately predicted this particular eclipse, but analysis of some partial cycles could have pointed him to another partial eclipse in the same year.
Thucydides describes how the Athenian army was defeated due to a lunar eclipse. The Athenians decided to lift the siege of Syracuse in Sicily and under cover of darkness on August 27, 413 BC. They began to load onto the ships, when suddenly an eclipse began. Panic arose among the soldiers, the evacuation failed, and the Athenian army was defeated by the Syracusans.
Modern eclipses.
From the middle of the 19th century. Solar eclipses began to be actively used to study the physics of the Sun. By 1900, astronomers had discovered that the shape of the corona and the intensity of its spectrum varied during the 11-year sunspot cycle. In those years, this could only be known by observing eclipses; Later, a coronagraph telescope was created that artificially eclipses the Sun and makes it possible to observe the interior of the corona on any day. But even now we can study weak coronal rays, explore fine details in the spectrum of the corona and test the “Einstein effect” ( see below) only during eclipses. Since 1950, radio telescopes began to be used during eclipses, and during an expedition to the Aleutian Islands it was possible to measure the effective diameter of the Sun during an eclipse at various radio frequencies, despite clouds and rain.
Astrophysical observations.
The eclipse of July 8, 1842, observed in Europe and Central Asia, was very fruitful for the study of the Sun. Then, for the first time, prominences were described in detail. During the eclipse of July 28, 1851, daguerreotypes of prominences were made and the chromosphere of the Sun was discovered. During the eclipse of August 18, 1868, P. Jansen (1824–1908) discovered that the spectra of prominences contained bright lines, and immediately realized that prominences could be observed outside of eclipses using a spectroscope. One yellow line in these spectra has never been observed in laboratories. The element to which it belongs was discovered only in 1895 and was named helium.
The Fraunhofer spectrum of the corona was also first observed during the 1868 eclipse. It is formed when sunlight is scattered by small particles of interplanetary dust. During an eclipse the following year, the American astronomer C. Young (1834–1908) discovered an unknown green line in the emission spectrum of the corona, which was attributed to the hypothetical element “corona.” Only in 1942, Swedish astrophysicist B. Edlen showed that this line is emitted by iron atoms, which, under the influence of high temperature, have lost 13 of their 26 electrons.
During the eclipse of December 22, 1870, Young discovered the solar "reversal layer." The normal spectrum of the Sun contains many dark absorption lines. But just before the start of a total eclipse, when only a narrow bright rim is visible, the dark lines suddenly become bright. This is observed for only a few seconds and is therefore called the “flash spectrum”. It was first photographed at an eclipse in Brazil on April 16, 1893.
Objects inside Mercury's orbit.
Within the framework of Newton's theory of gravity, the movement of Mercury does not find a complete explanation; therefore, at the end of the 19th century. a hypothesis arose that its movement was disturbed by an unknown planet located even closer to the Sun. Her searches were undertaken during eclipses. In 1878, two small celestial bodies were noticed, but they could not be discovered later. But in 1882 and 1893, comets close to the Sun were noticed.
Einstein effect.
Following the publication of the general theory of relativity in 1916, many solar eclipse expeditions tested Einstein's predicted 1.76º deviation in the positions of stars near the Sun. This is caused by the fact that near a massive celestial body the geometric properties of space-time change, which leads to the bending of light rays. To test this effect, stars are photographed near the Sun at the time of an eclipse, and then again, 6 months later, at night. English expeditions to Brazil and West Africa during the eclipse of May 19, 1919 were the first to measure the Einstein effect: a shift in the position of stars was discovered, but its value continued to be refined for more than 50 years by many expeditions to subsequent eclipses.
Eclipses involving other objects.
Walkthroughs.
Typically, transits are the moments when the path of Mercury or Venus passes against the background of the solar disk. In the 20th century there have been 13 transits of Mercury, including the last on November 15, 1999; the next one will be on May 7, 2003. Transits of Venus occur much less frequently: the last two were in 1874 and 1882, and the next ones will be in 2004 and 2012. In the 18th century. The transit of Venus was of great interest because it helped determine the distance to the Sun and discover the atmosphere on Venus. Now this is not such an important event.
Satellites of Jupiter.
The entry of one of Jupiter's four large satellites into the planet's shadow is easy to observe even with a small telescope. O. Roemer noticed that the moments of eclipse of satellites lag behind those calculated based on measurements made when the Earth was closer to Jupiter. In 1676 he correctly explained this by the finite speed of light and quite accurately determined its value.
Coatings.
In its movement, the Moon from time to time obscures stars and other space objects. Accurately measuring the decline in the brightness of an object at this moment makes it possible to determine its size and shape, as well as clarify the theory of the movement of the Moon itself.
Eclipsing binaries.
Many stars live in pairs, orbiting around a common center of mass. If the Earth is located near the plane of their orbits, then from time to time we observe stars eclipsing each other. Based on the course of the light curve and measurements of the radial velocities of stars, their sizes and masses can be determined.
Eclipse- an astronomical situation in which one celestial body blocks the light from another celestial body.
Most famous lunar And solar eclipses. There are also such phenomena as the passage of planets (Mercury and Venus) across the disk of the Sun.
Moon eclipse
A lunar eclipse 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.
Lunar eclipse diagram
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 said to be total lunar eclipse, when partially - about partial eclipse. Two necessary and sufficient conditions for the occurrence of a lunar eclipse are the full moon and the proximity of the Earth to lunar node.
As can be seen for an observer on Earth, on the imaginary celestial sphere the Moon crosses the ecliptic twice a month at positions called nodes. The full moon can fall on such a position, on a node, then a lunar eclipse can be observed. (Note: not to scale)
Full 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 darkened 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; These were, for example, the lunar eclipses of July 26, 1953, and July 16, 2000. In this case, the Moon passes through the center of the earth's shadow; total lunar eclipses of this type are called central, they differ from the non-central ones in the longer duration and lower brightness of the Moon during the total phase of the eclipse.
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. Since the earth's atmosphere is most transparent to 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. To estimate the brightness of an eclipse it is used Danjon scale.
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).
Danjon scale used to estimate the degree of darkening of the Moon during a total lunar eclipse. Proposed by astronomer Andre Danjon as a result of research into such a phenomenon as ashen moonlight when the Moon is illuminated by light passing through the upper layers of the Earth's atmosphere. The brightness of the Moon during an eclipse also depends on how deeply the Moon entered the Earth's shadow.
Two total lunar eclipses. Corresponding to 2 (left) and 4 (right) on the Danjon scale
Ash Moonlight - a phenomenon when we see the entire Moon, although only part of it is illuminated by the Sun. At the same time, the part of the Moon’s surface not illuminated by direct sunlight has a characteristic ashen color.
Ash Moonlight
It is observed shortly before and shortly after the new moon (at the beginning of the first quarter and at the end of the last quarter of the moon phases).
The glow of the surface of the Moon, not illuminated by direct sunlight, is formed by sunlight scattered by the Earth, and then reflected again by the Moon to the Earth. Thus, the route of photons of the Moon's ashen light is as follows: Sun → Earth → Moon → observer on Earth.
Photon route when observing ashen light: Sun → Earth → Moon → Earth
The reason for this phenomenon has been well known since Leonardo da Vinci And Mikhail Mestlin,
Alleged Self-Portrait of Leonardo da Vinci
Michael Möstlin
teachers Kepler, who for the first time gave the correct explanation for the ashen light.
Johannes Kepler
The crescent moon with ashen light, drawn by Leonardo da Vinci in the Codex Leicester
The first instrumental comparisons of the brightness of the ashen light and the crescent moon were made in 1850 by French astronomers Arago And Lozhie.
Dominique Francois Jean Arago
The bright crescent is the part directly illuminated by the Sun. The rest of the Moon is illuminated by light reflected from the Earth
Photographic studies of the ashen light of the Moon at the Pulkovo Observatory, carried out G. A. Tikhov, led him to the conclusion that the Earth from the Moon should look like a bluish disk, which was confirmed in 1969, when man landed on the Moon.
Gabriel Adrianovich Tikhov
He considered it important to conduct systematic observations of the ashen light. Observations of the ashen light of the Moon allow us to judge the change in the Earth's climate. The intensity of the ashen color depends to some extent on the amount of cloud cover on the currently illuminated side of the Earth; For the European part of Russia, bright ashen light reflected from powerful cyclonic activity in the Atlantic predicts precipitation in 7-10 days.
Partial 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.
View of the Moon during a lunar eclipse
Penumbral 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 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.
Periodicity
Due to the discrepancy between the planes of the lunar and earth's orbits, not every full moon is accompanied by a lunar eclipse, and not every lunar eclipse is a total one. The maximum number of lunar eclipses per year is 3, but in some years there is not a single lunar eclipse. 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.
Saros or draconian period, consisting of 223 synodic months(an average of approximately 6585.3213 days or 18.03 tropical years), after which the eclipses of the Moon and the Sun approximately repeat in the same order.
Synodic(from ancient Greek σύνοδος “connection, rapprochement”) month- the period of time between two successive identical phases of the Moon (for example, new moons). Duration is variable; the average value is 29.53058812 average solar days (29 days 12 hours 44 minutes 2.8 seconds), the actual duration of the synodic month differs from the average within 13 hours.
Anomalistic month- the period of time between two successive passages of the Moon through perigee in its movement around the Earth. The duration at the beginning of 1900 was 27.554551 average solar days (27 days 13 hours 18 minutes 33.16 seconds), decreasing by 0.095 seconds per 100 years.
This period is a consequence of the fact that the 223 synodic months of the Moon (18 calendar years and 10⅓ or 11⅓ days, depending on the number of leap years in a given period) are almost equal to 242 draconic months (6585.36 days), that is, after 6585⅓ days the Moon returns to the same syzygy and to the orbital node. The second luminary important for the onset of the eclipse - the Sun - returns to the same node, since almost an integer number of draconic years (19, or 6585.78 days) pass - the periods of the Sun's passage through the same node of the Moon's orbit. In addition, 239 anomalistic months The Moons are 6585.54 days long, so the corresponding eclipses in each Saros occur at the same distance of the Moon from the Earth and have the same duration. During one Saros, on average, 41 solar eclipses occur (of which approximately 10 are total) and 29 lunar eclipses. They first learned to predict lunar eclipses using saros in ancient Babylon. The best opportunities for predicting eclipses are provided by a period equal to triple Saros - exeligmos, containing an integer number of days, which was used in the Antikythera Mechanism.
Berosus calls a calendar period of 3600 years a saros; smaller periods were called: neros at 600 years and sosos at 60 years.
Solar eclipse
The longest solar eclipse occurred on January 15, 2010 in Southeast Asia and lasted more than 11 minutes.
A solar eclipse is an astronomical phenomenon in which the Moon covers (eclipses) all or part of the Sun from an observer on Earth. A solar eclipse is only possible during a new moon, 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 band, he sees 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 solar corona, which is not visible in the normal bright light of the Sun.
Elongated corona shape during the total solar eclipse of August 1, 2008 (close to the minimum between solar cycles 23 and 24)
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 can see it as 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 the phase Φ . 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 touch. 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. In 600 million years, tidal braking will move the Moon so far away from the Earth that a total solar eclipse will become impossible.
Astronomical classification of solar eclipses
According to astronomical classification, if an eclipse at least somewhere on the Earth's surface can be observed as total, it is called full.
Diagram of a total solar eclipse
If an 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 private. 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.
Animated annular eclipse
Diagram of an annular solar eclipse
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 visible in different parts of the eclipse band as total or annular. This type of eclipse is sometimes called a total annular (or hybrid) eclipse.
The shadow of the Moon on Earth during an eclipse, photograph from the ISS. The photo shows Cyprus and Türkiye
Frequency of solar eclipses
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. Thus, on the territory of Moscow from the 11th to the 18th centuries, 159 solar eclipses with a phase greater than 0.5 could be observed, of which only 3 were total (August 11, 1124, March 20, 1140, and June 7, 1415). Another total solar eclipse occurred on August 19, 1887. An annular eclipse could be observed in Moscow on April 26, 1827. A very strong eclipse with a phase of 0.96 occurred on July 9, 1945. The next total solar eclipse is expected in Moscow only on October 16, 2126.
Mention of eclipses in historical documents
Solar eclipses are often mentioned in ancient sources. An even greater number of dated descriptions are contained in Western European medieval chronicles and annals. For example, a solar eclipse is mentioned in the Annals of St. Maximin of Trier: “538 February 16, from the first to the third hour there was a solar eclipse.” A large number of descriptions of solar eclipses from ancient times are also contained in the chronicles of East Asia, primarily in the Dynastic histories of China, in Arab chronicles and Russian chronicles.
Mentions of solar eclipses in historical sources usually provide the opportunity for independent verification or clarification of the chronological relationship of the events described in them. If the eclipse is described in the source in insufficient detail, without indicating the location of observation, calendar date, time and phase, such identification is often ambiguous. In such cases, when ignoring the timing of the source over the entire historical interval, it is often possible to select several possible “candidates” for the role of a historical eclipse, which is actively used by some authors of pseudo-historical theories.
Discoveries made thanks to solar eclipses
Total solar eclipses make it possible to observe the corona and the immediate surroundings of the Sun, which is extremely difficult under normal conditions (although since 1996, astronomers have been able to constantly observe the surroundings of our star thanks to the work SOHO satellite(English) SolarandHeliosphericObservatory- solar and heliospheric observatory).
SOHO - solar observation spacecraft
French scientist Pierre Jansen During a total solar eclipse in India on August 18, 1868, he first explored the chromosphere of the Sun and obtained the spectrum of a new chemical element
Pierre Jules César Jansen
(although, as it turned out later, this spectrum could be obtained without waiting for a solar eclipse, which was done two months later by the English astronomer Norman Lockyer). This element was named after the Sun - helium.
In 1882, on May 17, during a solar eclipse, observers from Egypt noticed a comet flying near the Sun. She got the name Eclipse comets, although it has another name - comet Tewfik(in honor of Khedive Egypt at that time).
1882 Eclipse Comet(modern official designation: X/1882 K1) is a comet that was discovered by observers in Egypt during a solar eclipse of 1882.Her appearance was a complete surprise, and she was observed during an eclipse for the first and last time. She is a member of the familycircumsolar comets Kreutz Sungrazers, and was 4 months ahead of the appearance of another member of this family - the large September comet of 1882. Sometimes she is called comet Tewfik in honor of the Khedive of Egypt at that time Tevfika.
Khedive(khedive, khedif) (Persian - lord, sovereign) - the title of the Vice-Sultan of Egypt, which existed during the period of Egypt's dependence on Turkey (1867-1914). This title was held by Ismail, Tawfik and Abbas II.
Taufik Pasha
The role of eclipses in the culture and science of mankind
Since ancient times, solar and lunar eclipses, like other rare astronomical phenomena such as the appearance of comets, have been perceived as negative events. People were very afraid of eclipses, since they occur rarely and are unusual and frightening natural phenomena. In many cultures, eclipses were considered harbingers of misfortune and disaster (especially lunar eclipses, apparently due to the red color of the shadowed Moon, which was associated with blood). In mythology, eclipses were associated with the struggle of higher powers, one of which wants to disrupt the established order in the world (“extinguish” or “eat” the Sun, “kill” or “drench” the Moon with blood), and the other wants to preserve it. The beliefs of some peoples required complete silence and inaction during eclipses, while others, on the contrary, required active witchcraft to help the “light forces”. To some extent, this attitude towards eclipses persisted until modern times, despite the fact that the mechanism of eclipses had long been studied and generally known.
Eclipses have provided rich material for science. In ancient times, observations of eclipses helped to study celestial mechanics and understand the structure of the solar system. The observation of the Earth's shadow on the Moon provided the first “cosmic” evidence of the fact that our planet is spherical. Aristotle was the first to point out that the shape of the earth's shadow during lunar eclipses is always round, which proves the sphericity of the Earth. Solar eclipses made it possible to begin studying the corona of the Sun, which cannot be observed during normal times. During solar eclipses, the phenomena of gravitational curvature of light rays near a significant mass were first recorded, which became one of the first experimental proofs of the conclusions of the general theory of relativity. Observations of their passages across the solar disk played a major role in the study of the inner planets of the solar system. Thus, Lomonosov, observing the passage of Venus across the disk of the Sun in 1761, for the first time (30 years before Schröter and Herschel) discovered the Venusian atmosphere, discovering the refraction of solar rays when Venus enters and exits the solar disk.
Solar eclipse with the help of Moscow State University
Eclipse of the Sun by Saturn on September 15, 2006. Photo of the Cassini interplanetary station from a distance of 2.2 million km
In different parts of the Earth, a solar eclipse occurs at different times. Due to the movement of the Moon around the Earth and the rotation of the Earth around its axis, the shadow of the Moon moves along the Earth's surface approximately from west to east, forming a strip of shadow several thousand kilometers long and an average width of about 200 km (maximum width 270 km).
Rice.
The cause and types of solar eclipses can be shown by a simple experiment demonstrated in a darkened room.
To do this, you need to place an electric lamp on one end of a long table (preferably in a ball matte lampshade), on the other end - a geographical globe, and between them you need to hang a small ball on a thread. Illuminated by a lamp, the ball will cast a shadow and penumbra on the globe, i.e. demonstrate total and partial solar eclipses. By moving the ball slightly up and down, you can pass its shadow past the globe, leaving only a penumbra on it, which will show the cause of partial solar eclipses. Shifting the ball further in the same direction until its penumbra disappears from the globe will demonstrate a new moon without solar eclipses.
A solar eclipse begins from the right, western edge of the Sun, on the disk of which a small damage appears, shaped like a circle of the same radius. Gradually, the eclipse phase increases, and the solar disk takes the form of a continuously narrowing crescent, significantly different in shape from the crescent lunar phases, limited not by a circular, but by an elliptical terminator.
If the eclipse is partial, then in the middle of the eclipse its phase reaches a certain maximum value, and then decreases again, and the eclipse ends on the left, eastern edge of the solar disk. During partial eclipses, the weakening of sunlight is not noticeable (with the exception of eclipses with the largest phase close to 1), and the eclipse phases are visible only when observed through a dark filter.
In the full phase band, a solar eclipse also begins with partial phases, but when the Moon completely covers the Sun, twilight sets in, as in dark twilight, and the brightest stars and planets appear in the darkened sky, and around the Sun a beautiful radiant glow of pearl color is visible - the solar corona , representing the outer layers of the solar atmosphere, not visible outside of an eclipse due to their low brightness compared to the brightness of the daytime sky.
Rice.
A glow ring flashes above the entire horizon - this is where sunlight penetrates into the area covered with the lunar shadow from neighboring zones, where a total eclipse does not occur, but only a partial eclipse is observed. After all, the radiance and blue rays entering the sunlight are abundantly scattered by the earth’s atmosphere, while red and orange rays pass through it almost unhindered, and even the dense ground layer of air does not interfere with them.
That is why this layer of air is perceived as reddish-pink.
Eclipses can be annular (Fig. 6), total (Fig. 7) and partial.
A total eclipse is the best time to study the solar atmosphere: the silvery corona and the lower layer - the red chromosphere, above which fiery fountains of prominences rise.
Rice.
Rice.
Soon, most often after 2 - 3 minutes, the Moon opens the western solar edge, the total phase of the eclipse ends, the glow ring disappears, quickly brightens, stars, planets and the solar corona disappear.
By the way, the appearance of the solar corona changes from year to year, from disheveled in all directions to elongated along the solar equator. Obviously, the elongated appearance of the crown gave the ancient Egyptians a reason to depict the Sun as winged.
In each area, an eclipse begins and ends at different points in time, and its circumstances, including its duration, depend not only on the speed of movement of the lunar shadow (penumbra), but also on the location of this area in it.
The calculated circumstances of the eclipse are plotted on a geographic map, which in this case is called a solar eclipse map. It depicts lines connecting points on the earth's surface with certain identical quantities and therefore called isolines (from the Greek “izoz” - equal, identical). Thus, the isochrones of the beginning (end) of a partial eclipse pass through the points at which the partial eclipse begins (ends) at the same moment in a certain time counting system, for example, Moscow time. Isophases always connect points at which the greatest phase of the eclipse is the same (it is more correct to call them isophases of the greatest phase).
The duration of the entire eclipse and its total phase on the central line is calculated by the diameters of the lunar penumbra and shadow and by the speed of their movement along the earth's surface. These calculations, as well as the calculations of all the circumstances of solar eclipses for different areas of the Earth, are very complex, since the speed of the lunar shadow (and penumbra) on the earth's surface depends on the magnitude and direction of the geocentric speed of the Moon, on the geographic latitude of the area and on the angle of inclination of the cone of the lunar shadow to surface of this area.
But still, for the sake of clarity, it is possible to show at least an approximate principle for calculating the duration of a total solar eclipse on the central line of the total phase strip.
Since the movement of the Moon and the rotation of the Earth occur in the forward direction, the lunar shadow moves along the Earth’s surface at approximately the speed of:
where is the geocentric speed of the Moon and is the linear speed of points on the earth's surface in the direction of movement of the lunar shadow.
It is obvious that the longest duration of the total eclipse phase is possible only at the maximum diameter of the lunar shadow and only in the equatorial zone of the Earth, where the linear speed of points on the earth's surface is greatest and close to = 0.47 km/sec.
The maximum diameter of the lunar shadow, as we already know, is possible only at the smallest geocentric distance of the Moon, when its speed approaches = 1.08 km/sec. Therefore, the longest duration of the total phase of a solar eclipse is
and more accurate calculations lead to the value:
Periodicity of solar eclipses
Partial solar eclipses occur in every area, naturally, more often than total eclipses, since the diameter of the lunar penumbra, as has already been shown, significantly exceeds the diameter of the lunar shadow.
So, for example, Moscow accounted for 13 partial solar eclipses over 30 years, from 1952 to 1981 inclusive, i.e. in Moscow they occur on average every 2.3 years.
A similar picture is typical for many other places on the earth’s surface. But since during partial solar eclipses with a small phase the sunlight almost does not weaken, then they are simply not paid attention to and solar eclipses are classified as very rare natural phenomena.
But partial eclipses with a significant phase already arouse their interest, since studying a series of photographs of successive phases of the eclipse makes it possible to clarify the movement of the Moon and, if necessary, make appropriate amendments to the theory of its movement.
Astronomers must observe total solar eclipses, and for this they often have to go on very distant expeditions and install and adjust scientific equipment in advance, three to four weeks before the eclipse.
In addition to refinements for the theory of the motion of the Moon, a comparison of computational and observed contacts and phases of the eclipse helps to study insignificant deviations from the uniform rotation of the Earth, and the main goal of observing total solar eclipses is, of course, the study of the solar corona, the outer regions and rays of which are not visible outside the eclipse are visible.
In the few minutes that the total phase of the eclipse lasts, astronomers manage to use their instruments to obtain numerous photographs of the corona, taken in different colored rays, photographs of its spectrum, record changes in the intensity of its radio emission using self-recording equipment, and perform a number of other observations that are extremely necessary for studying the physical nature of the Sun and the processes occurring on it.
This study, in turn, helps astronomers understand the nature of numerous stars, only one of which is our Sun.
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