We present to you a selection of 20 of the most beautiful natural phenomena associated with the play of light. Truly natural phenomena are indescribable - you have to see it! =)

Let us conditionally divide all light metamorphoses into three subgroups. The first is Water and Ice, the second is Rays and Shadows, and the third is Light contrasts.

Water and Ice

“Near-horizontal Arc”

This phenomenon is also known as a “fire rainbow”. Created in the sky when light is refracted through ice crystals in cirrus clouds. This phenomenon is very rare, since both the ice crystals and the sun must be exactly in a horizontal line for such a spectacular refraction to occur. This particularly successful example was captured in the skies over Spokane in Washington in 2006.

A couple more examples of fire rainbows

When the sun shines on a climber or other object from above, a shadow is projected onto the fog, creating a curiously enlarged triangular shape. This effect is accompanied by a kind of halo around the object - colored circles of light that appear directly opposite the sun when sunlight is reflected by a cloud of identical water droplets. This natural phenomenon received its name due to the fact that it was most often observed on the low German peaks of Brocken, which are quite accessible to climbers, due to frequent fogs in this area

In a nutshell - it’s a rainbow upside down =) It’s like a huge multi-colored smiley face in the sky) This miracle is achieved due to the refraction of the sun’s rays through horizontal ice crystals in clouds of a certain shape. The phenomenon is concentrated at the zenith, parallel to the horizon, the color range is from blue at the zenith to red towards the horizon. This phenomenon is always in the form of an incomplete circular arc; bringing this situation full circle is the exceptionally rare Infantry Arc, which was first captured on film in 2007

Misty Arc

This strange halo was spotted from the Golden Gate Bridge in San Francisco - it looked like an all-white rainbow. Like a rainbow, this phenomenon is created due to the refraction of light through water droplets in the clouds, but, unlike a rainbow, due to the small size of the fog droplets, there seems to be a lack of color. Therefore, the rainbow turns out to be colorless - just white) Sailors often refer to them as “sea wolves” or “foggy arcs”

Rainbow halo

When light is scattered back (a mixture of reflection, refraction and diffraction) back to its source, the water droplets in the clouds, the shadow of an object between the cloud and the source can be divided into bands of color. Glory is also translated as unearthly beauty - a fairly accurate name for such a beautiful natural phenomenon) In some parts of China, this phenomenon is even called the Light of Buddha - it is often accompanied by the Brocken Ghost. In the photo, beautiful stripes of color effectively surround the shadow of the airplane opposite the cloud.

Halos are one of the most famous and common optical phenomena, and they appear under many guises. The most common phenomenon is the solar halo phenomenon, caused by the refraction of light by ice crystals in cirrus clouds at high altitude, and the specific shape and orientation of the crystals can create a change in the appearance of the halo. During very cold weather, halos formed by crystals near the ground reflect sunlight between them, sending it in several directions at once - this effect is known as “diamond dust.”

When the sun is at exactly the right angle behind the clouds, the water droplets in them refract the light, creating an intense trail. Coloration, as in a rainbow, is caused by different wavelengths of light - different wavelengths are refracted to different degrees, changing the angle of refraction and therefore the colors of light as we perceive them. In this photo, the iridescence of the cloud is accompanied by a sharply colored rainbow.

A few more photos of this phenomenon

The combination of a low Moon and dark skies often creates lunar arcs, essentially rainbows produced by the light of the moon. Appearing at the opposite end of the sky from the Moon, they usually appear completely white due to the faint coloring, but long exposure photography can capture the true colors, as in this photo taken in Yosemite National Park, California.

A few more photos of the lunar rainbow

This phenomenon appears as a white ring surrounding the sky, always at the same height above the horizon as the Sun. Usually it is possible to catch only fragments of the whole picture. Millions of vertically arranged ice crystals reflect the sun's rays across the sky to create this beautiful phenomenon.

So-called false Suns often appear on the sides of the resulting sphere, such as in this photo

Rainbows can take many forms: multiple arcs, intersecting arcs, red arcs, identical arcs, arcs with colored edges, dark stripes, “spokes” and many others, but what they have in common is that they are all divided into colors - red, orange, yellow , green, blue, indigo and violet. Do you remember from childhood the “memory” of the arrangement of colors in a rainbow - Every Hunter Wants to Know Where the Pheasant Sits? =) Rainbows appear when light is refracted through drops of water in the atmosphere, most often during rain, but haze or fog can also create similar effects, and are much rarer than one might imagine. At all times, many different cultures have attributed many meanings and explanations to rainbows, for example, the ancient Greeks believed that rainbows were the path to heaven, and the Irish believed that in the place where the rainbow ends, the leprechaun buried his pot of gold =)

More information and beautiful photos on the rainbow can be found

Rays and Shadows

A corona is a type of plasma atmosphere that surrounds an astronomical body. The most famous example of such a phenomenon is the corona around the Sun during a total eclipse. It extends thousands of kilometers in space and contains ionized iron heated to almost a million degrees Celsius. During an eclipse, its bright light surrounds the darkened sun and it seems as if a crown of light appears around the luminary

When dark areas or permeable obstacles, such as tree branches or clouds, filter the sun's rays, the rays create entire columns of light emanating from a single source in the sky. This phenomenon, often used in horror films, is usually observed at dawn or dusk and can even be witnessed under the ocean if the sun's rays pass through strips of broken ice. This beautiful photo was taken in Utah National Park

A few more examples

Fata Morgana

The interaction between cold air near ground level and warm air just above can act as a refractive lens and turn upside down the image of objects on the horizon, along which the actual image appears to oscillate. In this photo taken in Thuringia, Germany, the horizon in the distance appears to have disappeared altogether, although the blue portion of the road is simply a reflection of the sky above the horizon. The claim that mirages are completely non-existent images that appear only to people lost in the desert is incorrect, likely confused with the effects of extreme dehydration, which can cause hallucinations. Mirages are always based on real objects, although it is true that they may appear closer due to the mirage effect

The reflection of light by ice crystals with almost perfectly horizontal flat surfaces creates a strong beam. The light source can be the Sun, the Moon, or even artificial light. An interesting feature is that the pillar will have the color of that source. In this photo taken in Finland, the orange sunlight at sunset creates an equally orange gorgeous pillar

A couple more “sun pillars”)

Light contrasts

The collision of charged particles in the upper atmosphere often creates magnificent light patterns in the polar regions. Color depends on the elemental content of the particles - most auroras appear green or red due to oxygen, but nitrogen sometimes creates a deep blue or purple appearance. In the photo - the famous Aurora Borilis or Northern Lights, named after the Roman goddess of the dawn Aurora and the ancient Greek god of the north wind Boreas

This is what the Northern Lights look like from space

Condensation trail

The trails of steam that follow an airplane across the sky are some of the most stunning examples of human intervention in the atmosphere. They are created either by aircraft exhaust or air vortices from the wings and appear only in cold temperatures at high altitudes, condensing into ice droplets and water. In this photo, a bunch of contrails criss-cross the sky, creating a bizarre example of this unnatural phenomenon.

High-altitude winds bend the wakes of rockets, and their small exhaust particles turn sunlight into bright, iridescent colors that are sometimes carried by those same winds thousands of kilometers before they finally dissipate. The photo shows traces of a Minotaur missile launched from the US Air Force Base in Vandenberg, California.

The sky, like many other things around us, scatters polarized light that has a specific electromagnetic orientation. Polarization is always perpendicular to the light path itself, and if there is only one direction of polarization in the light, the light is said to be linearly polarized. This photo was taken with a polarized wide-angle filter lens to show how exciting the electromagnetic charge in the sky looks. Pay attention to what shade the sky has near the horizon, and what color it is at the very top.

Technically invisible to the naked eye, this phenomenon can be captured by leaving the camera with the lens open for at least an hour, or even overnight. The natural rotation of the Earth causes the stars in the sky to move across the horizon, creating remarkable trails in their wake. The only star in the evening sky that is always in one place is, of course, Polaris, since it is actually on the same axis with the Earth and its vibrations are noticeable only at the North Pole. The same would be true in the south, but there is no star bright enough to observe a similar effect

And here is a photo from the pole)

A faint triangular light seen in the evening sky and extending towards the heavens, the Zodiacal light is easily obscured by light atmospheric pollution or moonlight. This phenomenon is caused by the reflection of sunlight from dust particles in space, known as cosmic dust, hence its spectrum is absolutely identical to that of the Solar System. Solar radiation causes dust particles to slowly grow, creating a majestic constellation of lights gracefully scattered across the sky

Many people like funny pictures that trick their visual perception. But did you know that nature can also create optical illusions? Moreover, they look much more impressive than those made by humans. These include dozens of natural phenomena and formations, both rare and quite common. Northern lights, halo, green ray, lenticular clouds are just a small part of them. Here are 25 stunning optical illusions created by nature.
Fire waterfall "Horse Tail"

Every year in February, the water streams turn fiery orange.

This beautiful and at the same time frightening waterfall is located in the central part of Yosemite National Park. It is called Horsetail Fall (translated as “horse tail”). Every year, for 4-5 days in February, tourists can see a rare phenomenon - the rays of the setting sun reflected in the falling streams of water. At these moments, the waterfall turns fiery orange. It seems that hot lava is flowing from the top of the mountain, but this is just an optical illusion.

The Horse's Tail waterfall consists of two cascading streams, its total height reaches 650 meters.

False Sun

Real Sun and two false ones

If the Sun is low above the horizon and there are microscopic ice crystals in the atmosphere, observers may notice several bright rainbow specks to the right and left of the Sun. These bizarre halos faithfully follow our luminary across the sky, no matter which direction it is directed.

In principle, this atmospheric phenomenon is considered quite common, but it is difficult to notice the effect.

This is interesting: On rare occasions, when sunlight passes through cirrus clouds at just the right angle, these two spots become as bright as the Sun itself.

The effect is best observed in the early morning or late evening in polar regions.
Fata Morgana

Fata Morgana - a rare optical illusion

Fata Morgana is a complex optical atmospheric phenomenon. It is observed extremely rarely. In fact, Fata Morgana “consists” of several forms of mirages, due to which distant objects are distorted and “split into two” for the observer.

It is known that Fata Morgana occurs when several alternating layers of air with different densities are formed in the lower layer of the atmosphere (usually due to temperature differences). Under certain conditions they give specular reflections.

Due to the reflection and refraction of light rays, real-life objects can create several distorted images on the horizon or even above it, which partially overlap each other and rapidly change over time, thereby creating a striking picture of Fata Morgana.
Light pole

Column of light emanating from the sun descending below the horizon

We become witnesses of light (or solar) pillars quite often. This is the name of a common type of halo. This optical effect appears as a vertical stripe of light that extends from the sun at sunset or sunrise. A column of light can be observed when light in the atmosphere is reflected from the surface of tiny ice crystals, shaped like ice plates or miniature rods with a hexagonal cross-section. Crystals of this shape most often form in high cirrostratus clouds. But if the air temperature is low enough, they can appear in lower layers of the atmosphere. We think there is no need to explain why light pillars are most often observed in winter.
Brocken Ghost

Under certain conditions, a shadow can look like a ghost

When there is thick fog outside, you can observe an interesting optical phenomenon - the so-called Brocken ghost. To do this, you just need to turn your back to the main light source. The observer will be able to see his own shadow lying on the fog (or cloud if you are in a mountainous area).

This is interesting: If the light source, as well as the object on which the shadow is cast, are static, it will follow any human movement. But the shadow will appear completely differently on a moving “surface” (for example, on fog). In such conditions, it can fluctuate, creating the illusion that a dark, foggy silhouette is moving. It seems that this is not a shadow belonging to the observer, but a real ghost.

Atlantic Road in Norway

There are probably no more scenic highways in the world than the Atlantic Road, located in the Norwegian county of Møre og Romsdal.

The unique highway runs across the northern coast of the Atlantic Ocean and includes as many as 12 bridges connecting individual islands with road surfaces.

The most amazing place on the Atlantic Road is the Storseisundet Bridge. From a certain angle it may seem that it is not completed, and all the passing cars, going up, approach the cliff, and then fall down.

The total length of this bridge, opened in 1989, is 8.3 kilometers.

In 2005, the Atlantic Road was named Norway's "Build of the Century". And journalists from the British publication The Guardian awarded it the title of the best tourist route in this northern country.
Moon illusion

The Moon appears to be large when located above the horizon.

When the full Moon is low on the horizon, it is visually much larger than when it is high in the sky. This phenomenon seriously puzzles thousands of inquisitive minds trying to find some reasonable explanation for it. But in reality this is a simple illusion.

The simplest way to confirm the illusory nature of this effect is to hold a small round object (for example, a coin) in your outstretched hand. When you compare the size of this object with the “huge” Moon on the horizon and the “tiny” Moon in the sky, you will be surprised to realize that its relative size does not undergo any change. You can also roll a piece of paper into the shape of a tube and look through the hole formed solely at the Moon, without any surrounding objects. Again, the illusion will disappear.

This is interesting: Most scientists, when explaining the Moon illusion, refer to the theory of “relative size”. It is known that the visual perception of the size of an object visible to a person is determined by the dimensions of other objects observed by him at the same time. When the Moon is low above the horizon, other objects (houses, trees, etc.) come into a person’s field of vision. Against their background, our night star seems larger than in reality.

cloud shadows

Cloud shadows look like small islands

On a sunny day, from a great height, it is very interesting to observe the shadows cast by clouds on the surface of our planet. They resemble small, constantly moving islands in the ocean. Unfortunately, ground observers will not be able to appreciate all the splendor of this picture.
Moth atlas

Moth atlas

The huge atlas moth is found in tropical forests in southern Asia. It is this insect that holds the record for the surface area of ​​its wings (400 square centimeters). In India, this moth is bred to produce silk threads. The gigantic insect produces brown silk that looks like wool.

Due to their large size, atlas moths fly disgustingly, moving through the air slowly and clumsily. But the unique coloring of their wings helps them camouflage in their natural habitat. Thanks to her, the atlas literally merges with the trees.
Dew on the web

Dew on the web

In the morning or after rain, tiny droplets of water can be seen on the spider webs, resembling a necklace. If the web is very thin, the observer may have the illusion that the drops are literally floating in the air. And in the cold season, the web can be covered with frost or frozen dew; this picture looks no less impressive.
Green beam

Green beam

A short flash of green light, observed an instant before the solar disk appears over the horizon (most often at sea) or at the moment when the sun disappears behind it, is called a green ray.

You can witness this amazing phenomenon if three conditions are met: the horizon must be open (steppe, tundra, sea, mountainous areas), the air must be clean, and the area of ​​sunset or sunrise must be free of clouds.

As a rule, the green beam is visible for no more than 2-3 seconds. To significantly increase the time interval of its observation at the moment of sunset, you need to immediately after the appearance of the green beam begin to quickly run up an earthen embankment or climb the stairs. If the Sun is rising, you need to move in the opposite direction, that is, down.

This is interesting: During one of his flights over the South Pole, the famous American pilot Richard Byrd saw a green beam for a full 35 minutes! A unique incident occurred at the end of the polar night, when the upper edge of the solar disk first appeared over the horizon and slowly moved along it. It is known that at the poles the solar disk moves almost horizontally: the speed of its vertical rise is very small.

Physicists explain the effect of the green ray by the refraction (that is, refraction) of solar rays when passing through the atmosphere. Interestingly, at the moment of sunset or sunrise, we should see blue or violet rays first. But their wavelength is so short that when passing through the atmosphere they are almost completely scattered and do not reach the earthly observer.
Near-zenith arc

Near-zenith arc

Essentially, the near-zenith arc looks like a rainbow turned upside down. To some people, it even resembles a huge multi-colored smiley face in the sky. This phenomenon is formed due to the refraction of sunlight passing through ice crystals of a certain shape floating in the clouds. The arc is concentrated at the zenith parallel to the horizon. The top color of this rainbow is blue, the bottom is red.
Halo

Halo around the Moon

A halo is one of the most famous optical phenomena, observing which a person can see a luminous ring around a powerful light source.

During the day, a halo appears around the Sun, at night - around the Moon or other sources, for example, street lamps. There are a huge number of varieties of halos (one of them is the false Sun illusion mentioned above). Almost all halos are caused by the refraction of light as it passes through ice crystals concentrated in cirrus clouds (located in the upper troposphere). The appearance of the halo is determined by the shape and location of these miniature crystals.
Pink reflection of the sun

Pink reflection of the sun

Probably every inhabitant of our planet has seen the pink glow. This interesting phenomenon is observed at the moment when the Sun sets below the horizon. Then mountains or other vertical objects (for example, multi-story buildings) are painted a soft pink shade for a short time.
Crepuscular rays

Crepuscular rays

Scientists call twilight rays a common optical phenomenon that looks like an alternation of many light and dark stripes in the sky. Moreover, all these bands diverge from the current location of the Sun.

Twilight rays are one of the manifestations of the play of light and shadow. We are sure that the air is completely transparent, and the rays of light that pass through it are invisible. But if there are tiny droplets of water or dust particles in the atmosphere, sunlight is scattered. A whitish haze forms in the air. It is almost invisible in clear weather. But in cloudy conditions, particles of dust or water located in the shadow of clouds are less illuminated. Therefore, shaded areas are perceived by observers as dark stripes. Well-lit areas alternating with them, on the contrary, seem to us to be bright stripes of light.

A similar effect is observed when the sun's rays, breaking through cracks into a dark room, form bright light paths, illuminating dust particles floating in the air.

This is interesting: Crepuscular rays are called differently in different countries. The Germans use the expression “The sun drinks water,” the Dutch use “The sun stands on legs,” and the British call the twilight rays “Jacob’s ladder” or “ladder of angels.”

Anti-twilight rays

Anti-crepuscular rays emanate from a point on the horizon opposite the setting Sun

These rays are observed at the moment of sunset on the eastern side of the sky. They, like the twilight rays, fan out, the only difference between them is their location relative to the celestial body.

It may seem that the anti-twilight rays converge at some point beyond the horizon, but this is only an illusion. In reality, the sun's rays travel strictly in straight lines, but when these lines are projected onto the Earth's spherical atmosphere, arcs are formed. That is, the illusion of their fan-shaped divergence is determined by perspective.
Northern lights

Northern lights in the night sky

The sun is very unstable. Sometimes powerful explosions occur on its surface, after which the smallest particles of solar matter (solar wind) are directed toward the Earth at great speed. It takes them about 30 hours to reach Earth.

The magnetic field of our planet deflects these particles towards the poles, as a result of which extensive magnetic storms begin there. Protons and electrons penetrating the ionosphere from outer space interact with it. The thin layers of the atmosphere begin to glow. The entire sky is painted with colorful dynamically moving patterns: arcs, bizarre lines, crowns and spots.

This is interesting: The northern lights can be observed at high latitudes of each hemisphere (therefore, it would be more correct to call this phenomenon “aurora”). The geography of places where people can see this impressive natural phenomenon expands significantly only during periods of high solar activity. Surprisingly, auroras also occur on other planets of our solar system.

The shapes and colors of the colorful glow of the night sky change rapidly. Interestingly, auroras occur exclusively in altitude intervals from 80 to 100 and from 400 to 1000 kilometers above ground level.
Krushinnitsa

Krushinnitsa - a butterfly with incredibly realistic natural camouflage

In early April, when consistently warm and sunny weather sets in, you can notice a beautiful light speck fluttering from one spring flower to another. This is a butterfly called buckthorn or lemongrass.

The wingspan of the buckthorn is about 6 centimeters, the length of the wings is from 2.7 to 3.3 centimeters. Interestingly, the colors of males and females are different. Males have bright greenish-lemon wings, while females have lighter, almost white wings.

Krushinnitsa has amazingly realistic natural camouflage. It is very difficult to distinguish it from plant leaves.

Magnetic Hill

Cars seem to be rolling uphill under the influence of an unknown force.

There is a hill in Canada where extraordinary things happen. By parking the car near its foot and turning on the neutral gear, you will see that the car begins to roll (without any assistance) upward, that is, towards the rise. Many people explain the amazing phenomenon by the influence of an incredibly powerful magnetic force, causing cars to roll up hills and reach speeds of up to 40 kilometers per hour.

Unfortunately, there is no magnetism or magic here. It's all about an ordinary optical illusion. Due to the features of the terrain, a slight slope (about 2.5 degrees) is perceived by the observer as an upward climb.

The main factor in creating such an illusion, observed in many other places on the globe, is zero or minimal visibility of the horizon. If a person does not see it, then it becomes quite difficult to judge the inclination of the surface. Even objects that are in most cases located perpendicular to the ground (for example, trees) can lean in any direction, misleading the observer even more.
Salt deserts

It seems as if all these people are floating in the sky

Salt deserts are found in all corners of the Earth. People in the middle of them have a distorted perception of space due to the lack of any landmarks.

In the photo you can see a dried-up salt lake located in the southern part of the Altiplano plain (Bolivia) and called the Uyuni salt flat. This place is located at an altitude of 3.7 kilometers above sea level, and its total area exceeds 10.5 thousand square kilometers. Uyuni is the largest salt marsh on our planet.

The most common minerals found here are halite and gypsum. And the thickness of the layer of table salt on the surface of the salt marsh in some places reaches 8 meters. Total salt reserves are estimated at 10 billion tons. On the territory of Uyuni there are several hotels built from salt blocks. Furniture and other interior items are also made from it. And there are notices on the walls of the rooms: the administration politely asks guests not to lick anything. By the way, you can spend the night in such hotels for only 20 dollars.

This is interesting: During the rainy season, Uyuni is covered with a thin layer of water, thanks to which it turns into the largest mirror surface on Earth. In the middle of the endless mirror space, observers get the impression that they are soaring in the sky or even on another planet.

Wave

Sand dunes turned to stone

The Wave is a naturally formed gallery of sand and rock, located on the border of the American states of Utah and Arizona. Popular national parks in the United States are nearby, so the Wave attracts hundreds of thousands of tourists every year.

Scientists claim that these unique rock formations were formed over millions of years: the sand dunes gradually hardened under the influence of environmental conditions. And the wind and rain, which acted on these formations for a long time, polished their shapes and gave them such an unusual appearance.
Apache Indian Head

It's hard to believe that this rock formation was formed without human intervention

This natural rock formation in France vividly illustrates our ability to recognize familiar shapes, such as human faces, in surrounding objects. Scientists have recently discovered that we even have a special part of the brain responsible for recognizing faces. It is interesting that human visual perception is structured in such a way that any objects similar in outline to faces are noticed by us faster than other visual stimuli.

There are hundreds of natural formations in the world that exploit this human ability. But you must agree: the mountain range in the shape of the head of an Apache Indian is probably the most striking of them all. By the way, tourists who had the opportunity to see this unusual rock formation located in the French Alps cannot believe that it was formed without human intervention.‎
Wasteland Guardian

An Indian in a traditional headdress and with headphones in his ears - where else can you see this?

The Guardian of the Wasteland (another name is “Indian Head”) is a unique geoformation located near the Canadian city of Madisen Hat (southeastern part of Alberta). When looking at it from a great height, it becomes obvious that the terrain forms the outline of the head of a local aborigine in a traditional Indian headdress, looking intently somewhere to the west. Moreover, this Indian also listens to modern headphones.

In fact, what resembles a headphone wire is the path leading to the oil rig, and the liner is the well itself. The height of the “Indian head” is 255 meters, width - 225 meters. For comparison, the height of the famous bas-relief at Mount Rushmore, on which the faces of four American presidents are carved, is only 18 meters.

The Wasteland Guardian was formed naturally through the weathering and erosion of soft, clay-rich soil. According to scientists, the age of this geoformation does not exceed 800 years.
Lenticular clouds

Lenticular clouds look like huge UFOs

The unique feature of lenticular clouds is that no matter how strong the wind is, they remain motionless. Air currents sweeping over the earth's surface flow around obstacles, resulting in the formation of air waves. Lenticular clouds form at their edges. In their lower part there is a continuous process of condensation of water vapor rising from the surface of the earth. Therefore, lenticular clouds do not change their position. They just hang in the sky in one place.

Lenticular clouds most often form on the leeward side of mountain ranges or over individual peaks at altitudes from 2 to 15 kilometers. In most cases, their appearance signals an approaching atmospheric front.

This is interesting: Due to their unusual shape and absolute immobility, people often mistake lenticular clouds for UFOs.

Clouds with thunderstorm

Such a sight inspires fear, you must agree!

Horrifying clouds with thunderstorms are observed quite often in flat areas. They descend very low to the ground. There is a feeling that if you climb to the roof of the building, you can reach them with your hand. And sometimes it may seem that such clouds are even in contact with the surface of the earth.

A thunderstorm (another name is a squall gate) is visually similar to a tornado. Fortunately, in comparison with this natural phenomenon, it is not so dangerous. A thunderstorm is simply a low, horizontally oriented area of ​​a thundercloud. It is formed in its front part during rapid movement. And the squall gate acquires an even and smooth shape under conditions of active upward air movement. Such clouds, as a rule, form during the warm period of the year (from mid-spring to mid-autumn). Interestingly, the lifespan of thunderstorms is very short - from 30 minutes to 3 hours.

Agree, many of the phenomena listed above seem truly magical, even though their mechanisms can be easily explained from a scientific point of view. Nature, without the slightest human participation, creates amazing optical illusions that amaze the imagination of even researchers who have seen a lot of things in their lifetime. How can one not admire its greatness and power?

Answers and evaluation criteria

Exercise 1

The photographs show various celestial phenomena. Please indicate what

the phenomenon is depicted in each photograph, keeping in mind that the images are not

inverted, and observations were made from the mid-latitudes of the Northern

hemispheres of the Earth.

All-Russian Olympiad for schoolchildren in astronomy 2016–2017 academic year. G.

Municipal stage. 8–9 grades

Answers Please note that the question asks about what phenomenon is depicted in the picture (and not the object!). Based on this, the assessment is made.

1) meteor (1 point; “meteorite” or “fireball” are not counted);

2) meteor shower (another option is “meteor shower”) (1 point);

3) coverage of Mars by the Moon (another option is “coverage of the planet by the Moon”) (1 point);

4) sunset (1 point);

5) occultation of a star by the Moon (the short version “covering” is possible) (1 point);

6) setting of the Moon (possible answer is “neomenia” - the first appearance of the young Moon in the sky after the new moon) (1 point);

7) annular solar eclipse (the short version “solar eclipse” is possible) (1 point);

8) lunar eclipse (1 point);

9) discovery of a star by the Moon (the “end of occultation” option is possible) (1 point);

10) total solar eclipse (option “solar eclipse” is possible) (1 point);

11) passage of Venus across the disk of the Sun (the option “passage of Mercury across the disk of the Sun” or “passage of a planet across the disk of the Sun” is possible) (1 point);

12) ashen light of the Moon (1 point).

Note: All valid answer options are written in parentheses.

The maximum score for the task is 12 points.

Task 2 The figures show figures of several constellations. Under each figure its number is indicated. Indicate in your answer the name of each constellation (write down the pairs “picture number - name in Russian”).

2 All-Russian Olympiad for schoolchildren in astronomy 2016–2017 academic year. G.

Municipal stage. Grades 8–9 Answers

1) Swan (1 point);

2) Orion (1 point);

3) Hercules (1 point);

4) Ursa Major (1 point);

5) Cassiopeia (1 point);

6) Leo (1 point);

7) Lyra (1 point);

8) Cepheus (1 point);

9) Eagle (1 point).

The maximum for the task is 9 points.

3 All-Russian Olympiad for schoolchildren in astronomy 2016–2017 academic year. G.

Municipal stage. Grades 8–9 Task 3 Draw the correct sequence of changes in lunar phases (it is enough to draw the main phases) when observed from the middle latitudes of the Earth’s Northern Hemisphere. Sign their names. Start the drawing with the full moon, shade the parts of the moon not illuminated by the Sun.

One of the possible drawing options (2 points for the correct option):

The main phases are usually considered full moon, last quarter, new moon, first quarter (3 points). The phases of the moon are listed here in the order in which they are shown in the figure.

If one of the phases in the figure is missing, 1 point is deducted. For incorrectly indicating the phase name, 1 point is deducted. The grade for a task cannot be negative.

When evaluating a drawing, you must pay attention to the fact that the terminator (the light/dark boundary on the surface of the Moon) passes through the poles of the Moon (i.e., drawing the phase like a “bitten off apple”) is unacceptable. If this is not true in the answer, the score is reduced by 1 point.

Note: the solution shows a minimal version of the drawing. It is not necessary to draw the Moon at the full moon again at the end.

It is acceptable to depict intermediate phases:

The maximum score for the task is 5 points.

4 All-Russian Olympiad for schoolchildren in astronomy 2016–2017 academic year. G.

Municipal stage. Grades 8–9 Task 4 Mars, located in the eastern square, and the Moon are observed in conjunction. What is the phase of the moon at this moment? Explain your answer and provide a drawing showing the situation described.

Answer The figure shows the positions of all the bodies involved in the described situation (such a figure should be given in the work: 3 points). With this position of the Moon relative to the Earth and the Sun, the first quarter (waxing Moon) will be observed (2 points).

Note: the drawing may be slightly different (for example, the view of the relative position of the luminaries in the sky for an observer on the surface of the Earth), the main thing is that the relative positions of the bodies are indicated correctly and it is clear why the Moon will be in exactly the phase that is given in the answer.

The maximum score for the task is 5 points.

Task 5 At what average speed does the day/night boundary move on the surface of the Moon (R = 1738 km) in the region of its equator? Express your answer in km/h and round to the nearest whole number.

For reference: the synodic period of revolution of the Moon (the period of change of lunar phases) is approximately equal to 29.5 days, the sidereal period of revolution (the period of axial rotation of the Moon) is approximately equal to 27.3 days.

Answer The length of the equator of the Moon L = 2R 2 1738 3.14 = 10 920.2 km (1 point). To solve the problem, it is necessary to use the value of the synodic period 5 All-Russian Olympiad for Schoolchildren in Astronomy 2016–2017 academic year. G.

Municipal stage. 8–9 classes of circulation, because The movement of the day/night boundary on the surface of the Moon is responsible not only for the rotation of the Moon around its axis, but also for the position of the Sun relative to the Moon, which changes due to the movement of the Earth in its orbit. The period of change of lunar phases is P 29.5 days. = 708 hours (2 points – if there is no explanation why this particular period was used; 4 points – if there is a correct explanation; for using the sidereal period 1 point). This means that the speed will be V = L/P = 10,920.2/708 km/h 15 km/h (1 point; this point is given for calculating the speed, including when using the value 27.3 - the answer will be 16 .7 km/h).

Note: the solution can be done "in one line". This does not reduce the score. For an answer without a solution, score 1 point.

Task 6 Are there regions on Earth (if so, where are they located) where at some point in time all the zodiac constellations are on the horizon?

Answer As you know, the constellations through which the Sun passes, i.e., which are crossed by the ecliptic, are called zodiacal. This means we need to determine where and when the ecliptic coincides with the horizon. At this moment, not only the planes of the horizon and the ecliptic will coincide, but also the poles of the ecliptic with the zenith and nadir. That is, at this moment one of the poles of the ecliptic passes through the zenith. Coordinates of the north pole of the ecliptic (see.

drawing):

90° 66.5° and south, because it is at the opposite point:

90° 66.5° A point with a declination of ±66.5° culminates at the zenith of the Arctic Circle (North or South):.

Of course, deviations from the Arctic Circle by several degrees are possible, because...

Constellations are fairly extended objects.

The score for the problem (complete solution - 6 points) consists of the correct explanation of the condition (the culmination of the ecliptic pole at the zenith or, for example, the simultaneous upper and lower culmination of two opposite points 6 All-Russian Olympiad for Schoolchildren in Astronomy 2016–2017 academic year.

Municipal stage. 8–9 classes of the ecliptic on the horizon), in which the described situation is possible (3 points), a correct determination of the latitude of observation (2 points), an indication that there will be two such areas - in the Northern and Southern Hemispheres of the Earth (1 point).

Note: it is not necessary to determine the coordinates of the poles of the ecliptic, as is done in the solution (they can be known). Let's assume a different solution.

The maximum for the task is 6 points.

–  –  –

Option 2 You can not immediately substitute numerical values ​​into formulas, but convert them by expressing the orbital period through the average density of the Moon (the density value is not given in the condition, but the student can calculate it or know it - the approximate value is 3300 kg/m3):

–  –  –

(here M is the mass of the Sun, m is the mass of the satellite, Tz, mz and az are the period of revolution of the Earth around the Sun, the mass of the Earth and the radius of the Earth’s orbit, respectively).

It is possible to write this law for another set of bodies, for example, for the Earth–Moon system (instead of the Sun–Earth system).

Neglecting small masses compared to large ones, we get:

–  –  –

And the period of appearance of the station near the limb will be half the orbital one:

Evaluation Other solutions are also acceptable. All solution options should lead to the same answers (some deviations are acceptable due to the fact that slightly different numerical values ​​may be used in options 2 and 3, as well as in other options).

Options 1 and 2. Determining the length of the satellite’s orbit (2Rл 10,920 km) – 1 point; determination of the satellite’s orbital velocity Vl – 2 points; calculation 8 All-Russian Olympiad for schoolchildren in astronomy 2016–2017 academic year. G.

Municipal stage. 8–9 grades of circulation period – 1 point; finding the answer (dividing the orbital period by 2) – 2 points.

Option 3. Writing Kepler's 3rd law in a refined form for the bodies involved in the problem - 2 points (if the law is written in general form and the solution ends there - 1 point).

Correct neglect of small masses (i.e., the mass of the satellite compared to the mass of the Moon, the mass of the Earth compared to the mass of the Sun, the mass of the Moon compared to the mass of the Earth) – 1 point (these masses can be immediately omitted in the formula, a point for that is all is set equally). Writing an expression for the satellite period – 1 point, finding the answer (dividing the orbital period by 2) – 2 points.

If the final answer is too precise (the number of decimal places is more than two), 1 point will be deducted.

Note: you can not neglect the height of the orbit compared to the radius of the Moon (the numerical answer will remain virtually unchanged). You are allowed to immediately use the ready-made formula for the circulation period (the last form of writing the formula in the solution in option 2) - the score for this is not reduced (if the calculations are correct - 4 points for this stage of the solution).

The maximum for the task is 6 points.

Task 8 Let's assume that scientists have created a stationary Large Polar Telescope to observe the daily rotation of stars directly near the celestial pole, pointing its telescope exactly at the north celestial pole. Exactly in the center of their field of view, they discovered a Very Interesting Extragalactic Source. The field of view of this telescope is 10 arc minutes. After how many years will scientists no longer be able to observe this Source using this telescope?

Answer The celestial pole rotates around the ecliptic pole with a period of approximately Tp 26,000 years (1 point). The angular distance between these poles (2 points) is nothing more than 23.5° (i.e., 90° is the angle of inclination of the Earth’s rotation axis to the ecliptic plane). Since the celestial pole moves along a small circle of the celestial sphere, the angular velocity of its movement relative to the observer will be less than the angular velocity of rotation of a point on the celestial equator by 1/sin() times (2 points).

Since the telescope initially looks exactly at the celestial pole and at the Source, the maximum possible time for observing the Source will be:

15 years (3 points).

° After this time, the Source will leave the field of view of the telescope (the celestial pole will still be in the center of the field, since the telescope on Earth is stationary, 9 All-Russian Olympiad for Schoolchildren in Astronomy 2016–2017 academic year.

Municipal stage. 8–9 grades being initially aimed at the celestial pole; Let us recall that the celestial pole is essentially the point of intersection of the continuation of the Earth’s rotation axis with the celestial sphere).

If in the final answer the student does not separate the positions of the celestial pole and the Source, then with a correct numerical answer no more than 6 points are awarded.

Note: you can use cos(90-) or cos(66.5°) instead of sin() throughout the solution. Other solutions to the problem are possible.

The maximum for the task is 8 points.

Exercise 1

The photographs show various celestial phenomena. Indicate what phenomenon is depicted in each image, keeping in mind that the images are not upside down and the observations were made from the mid-latitudes of the Earth's Northern Hemisphere.

Answers

Please note that the question asks about what phenomenon is depicted in the picture (and not the object!). Based on this, the assessment is made.

1. meteor (1 point; “meteorite” or “fireball” do not count);
2. meteor shower (another option is “meteor shower”) (1 point);
3. coverage of Mars by the Moon (another option is “coverage of the planet by the Moon”) (1 point);
4. sunset (1 point);
5. occultation of a star by the Moon (the short version “covering” is possible) (1 point);
6. moonset (possible answer is “neomenia” - the first appearance of the young Moon in the sky after the new moon) (1 point);
7. annular solar eclipse (the short version “solar eclipse” is possible) (1 point);
8. lunar eclipse (1 point);
9. discovery of a star by the Moon (the “end of occultation” option is possible) (1 point);
10. total solar eclipse (option “solar eclipse” is possible) (1 point);
11. passage of Venus across the disk of the Sun (the option “passage of Mercury across the disk of the Sun” or “passage of a planet across the disk of the Sun” is possible) (1 point);
12. ashen light of the moon (1 point).

Note: All valid answer options are written in parentheses.

The maximum score for the task is 12 points.

Task 2

The figures show figures of several constellations. Under each figure its number is indicated. Indicate in your answer the name of each constellation (write down the pairs “picture number - name in Russian”).

Answers

1. Swan (1 point);
2. Orion (1 point);
3. Hercules (1 point);
4. Ursa Major (1 point);
5. Cassiopeia (1 point);
6. Leo (1 point);
7. Lyra (1 point);
8. Cepheus (1 point);
9. Eagle (1 point).

Maximum per task – 9 points.

Task 3

Draw the correct sequence of changes in lunar phases (it is enough to draw the main phases) when observed from the middle latitudes of the Northern Hemisphere of the Earth. Sign their names. Start your drawing with the full moon, shade the parts of the moon not illuminated by the Sun.

Answer

One of the possible drawing options (2 points for the correct option):

The main phases are usually considered full moon, last quarter, new moon, first quarter (3 points). The phases of the moon are listed here in the order in which they are shown in the figure.

If one of the phases in the figure is missing, 1 point is deducted. For incorrectly indicating the phase name, 1 point is deducted. The grade for a task cannot be negative.

When evaluating a drawing, you must pay attention to the fact that the terminator (the light/dark boundary on the surface of the Moon) passes through the poles of the Moon (i.e., drawing the phase like a “bitten off apple”) is unacceptable. If this is not true in the answer, the score is reduced by 1 point.

Note: The solution shows a minimal version of the drawing. It is not necessary to draw the Moon at the full moon again at the end. It is acceptable to depict intermediate phases:

Maximum per task – 5 points.

Task 4

The relative positions of Mars, Earth and the Sun at some point in time are shown in the figure. The Moon is observed in conjunction with Mars. What is the phase of the moon at this moment? Explain your answer.

Answer

At the described position of the Moon, the last quarter will be observed (4 points). The answer “first quarter” is worth 1 point. The answer “quarter” is worth 2 points. The answer “the left side of the Moon will be illuminated” is worth 1 point.

Maximum per task – 4 points.

Task 5

At what average speed does the day/night boundary move on the surface of the Moon (R = 1738 km) in the region of its equator? Express your answer in km/h and round to the nearest whole number. For reference: the synodic period of revolution of the Moon (the period of change of lunar phases) is approximately equal to 29.5 days, the sidereal period of revolution (the period of axial rotation of the Moon) is approximately equal to 27.3 days.

Answer

The length of the Moon's equator L = 2πR ≈ 2 × 1738 × 3.14 = 10,920.2 km (1 point). To solve the problem, it is necessary to use the value of the synodic period of revolution, since not only the rotation of the Moon around its axis, but also the position of the Sun relative to the Moon, which changes due to the movement of the Earth in its orbit, is responsible for the movement of the day/night boundary on the surface of the Moon. The period of change of lunar phases is P ≈ 29.5 days. = 708 hours (2 points – if there is no explanation why this particular period was used; 4 points – if there is a correct explanation; for using the sidereal period 1 point). This means that the speed will be V = L/P = 10,920.2/708 km/h ≈ 15 km/h (1 point; this point is given for calculating the speed, including when using the value 27.3 - the answer will be 16.7 km/h).

Note: the solution can be done "in one line". This does not reduce the score. For an answer without a solution, score 1 point.

Maximum per task – 6 points.

Task 6

Are there regions on Earth (if so, where are they located) where at some point in time all the zodiac constellations are on the horizon?

Answer

As you know, constellations through which the Sun passes, i.e., which are crossed by the ecliptic, are called zodiacal. This means we need to determine where and when the ecliptic coincides with the horizon. At this moment, not only the planes of the horizon and the ecliptic will coincide, but also the poles of the ecliptic with the zenith and nadir. That is, at this moment one of the poles of the ecliptic passes through the zenith. Coordinates of the north pole of the ecliptic (see picture):

δ n = 90° – ε = 66.5°

and southern, because it is at the opposite point:

δ n = –(90° – ε) = –66.5°

α n = 6 h

A point with a declination of ±66.5° culminates at the zenith on the Arctic Circle (North or South): h = 90 – φ + δ.

Of course, deviations from the Arctic Circle by several degrees are possible, since constellations are quite extended objects.

The score for the problem (complete solution - 6 points) consists of the correct explanation of the condition (the culmination of the ecliptic pole at the zenith or, for example, the simultaneous upper and lower culmination of two opposite points of the ecliptic on the horizon), under which the described situation is possible (2 points), the correct definition latitude of observation (3 points), indications that there will be two such areas - in the Northern and Southern Hemispheres of the Earth (1 point).

Note: It is not necessary to determine the coordinates of the poles of the ecliptic, as is done in the solution (they can be known). Let's assume a different solution.

Maximum per task – 6 points.

Total for the work - 42 points.

Zodiacal light

Zodiacal light often masks moonlight and artificial city light. On a quiet moonless night in nature, the likelihood that you will see the zodiacal light is quite high. This phenomenon is observed as a result of the reflection of solar rays from particles of cosmic dust surrounding the Earth.

rainbow wall

A rare atmospheric phenomenon also known as a “fire rainbow” occurs when the horizontal rays of the rising or setting sun are refracted through horizontally located cloud ice crystals. The result is a kind of wall painted in different colors of the rainbow. The photo was taken in the skies of Washington in 2006.

The sun's rays are reflected from ice crystals located at an angle of 22° relative to the Sun in high-altitude clouds. Different positions of ice crystals can cause halo modifications. On frosty days, a “diamond dust” effect can be observed, in which case the sun’s rays are repeatedly reflected from ice crystals.

Airplane contrails

Airplane exhaust and eddy currents at high altitudes turn ice particles into water. The long white streaks high in the sky are nothing more than suspended water droplets.

Crepuscular rays

The rays of the setting sun passing through gaps in the clouds form clearly visible individual beams of sunlight. Very often such rays of the sun can be seen in various science fiction films. This photo was taken in one of the national parks in Utah.

Northern lights

The Northern Lights are nothing more than a collision in the upper layers of the atmosphere of solar rays with charged particles of gases from the Earth's magnetic field.

Star trails

A visual demonstration of the Earth's rotation. This phenomenon is invisible to the ordinary eye. To get such a photograph, you need to set the camera to a long shutter speed. In the picture, only the only North Star, located almost above the Earth’s axis, remains almost motionless.

White rainbow

Photo taken on the Golden Gate Bridge in San Francisco. The small size of airy water droplets makes it impossible to decompose the sun's rays into spectra of colors, so the rainbow is only white.

Buddha Light

This photo was taken in China. The phenomenon is similar to the “Ghost of Brocken”. The sun's rays are reflected from atmospheric droplets of water over the sea, the shadow in the middle of the rainbow circle of reflected rays is the shadow of an airplane.

Rainbow upside down

Such an unusual rainbow also appears as a result of the refraction of sunlight through ice crystals located only in certain parts of the clouds.

A very common atmospheric phenomenon. It can be observed not only in the desert, but also on the road in the sultry heat. This phenomenon is formed as a result of the refraction of sunlight through a “lens” formed by layers of colder (at the surface of the earth) and warmer (located above) air. This kind of lens reflects objects located above the horizon, in this case the sky. Photo taken in Thuringia (Germany).

Shimmering Clouds

The rays of the setting sun at right angles “bump into” the water droplets of the clouds. As a result of diffraction (the bending of water droplets by the sun's rays) and the interference of sun rays (the decomposition of sun rays into spectra), as in Photoshop, the cloud figure is filled with a gradient fill.

Rocket exhaust trail

The trail of a Minotaur missile fired by the US Air Force in California. Air currents blowing at different altitudes at different speeds cause distortion in the wake of rocket exhausts. Atmospheric droplets of water and melted ice crystals also cause the decomposition of sunlight into different colors of the rainbow.

Ghost of Brocken, Germany

This phenomenon occurs on a foggy morning. The rainbow solar disk appears opposite the sun, as a result of the reflection of sunlight from droplets of water in the fog. The curious triangular shadow breaking the iridescent disk of reflected sunlight is nothing more than a projection of the upper surface of the clouds.