There is a circle of clouds around the moon. Halo by photographer Juan Miguel Castillo Navarro from Mexico. Amazing in nature
Seeing a rainbow, most of us smile and remember our childhood when this natural phenomenon was seen for the first time. There are many signs associated with, but a multi-colored arc closing around the sun looks especially unusual and mystical. In science, this phenomenon is called a halo.
What kind of phenomenon is a rainbow around the sun?
There are many types of halos, but all are caused by ice crystals in cirrus clouds. The type of halo depends on their shape and location. The light that is reflected and refracted by ice crystals is often decomposed into a spectrum, which causes the halo to resemble a rainbow. The halo that forms around the moon has no color, because it is simply impossible to distinguish it at dusk. This phenomenon is recorded in any weather, and in frosty conditions the crystals are located very close to the surface of the earth and resemble shining precious stones, the so-called diamond dust.
The lower part of the halo can be seen against the background of the surrounding landscape if the main luminary is located low above the horizon. However, halos are not the same as crowns. The latest natural phenomenon is associated with the formation of light, foggy rings in the sky around the Sun or Moon.
What does a rainbow around the sun mean?
Those lucky enough to see this rare phenomenon should expect all the best - prosperity, prosperity, luck and love. If before this there was not the easiest period in life, then it will definitely end and everything will work out in the best possible way.
If there are such signs associated with a circular rainbow around the sun:
There are a lot of historical facts related to the halo, when this natural phenomenon helped those who saw it in some matters or, on the contrary, was interpreted as a bad sign. In particular, the “Tale of Igor’s Campaign” says that the army was finally defeated when four Suns appeared in the sky. Ivan the Terrible regarded the natural phenomenon he saw as an omen of imminent death. There are a lot of superstitions about rainbows. This belief is quite interesting: if you take a sip of water from the river where the rainbow originates, you can wish for the gender of your child. True, this applies only to those women who already have three daughters or three sons.
The sky is an amazing thing, constantly changing and diverse. But how often do we turn our attention to the sky? Usually people do not notice and are not interested in what is happening in the sky. And only when strange phenomena occur in it, attention to it increases and they begin to say that the sky is giving people signs. One of these unusual natural phenomena is considered halo- light arcs or circles around the sun or moon. But where do they come from and why do they disappear as suddenly as they appear? Let's look into this issue together.
So the word " halo" comes from the Greek word " halo", which means "circle" or "disk". The closest natural phenomenon to a halo, which is familiar to us, is a rainbow, that is, the refraction of the rays of a celestial body. But unlike a rainbow, which can only be observed in the daytime, standing with your back to the sun, in air saturated with moisture, a halo appears in the sky at any time of the day - around the sun or moon (and sometimes near a powerful source of artificial light).
Nature halo phenomena in the sky (5-10 km above the ground, in the upper layers of the troposphere) - refraction and decomposition into a spectrum of light rays ( dispersion) in the smallest ice crystals, as well as their reflection from the side faces or bases of these crystals, which have the shape of hexagonal columns or plates. Crystals can be of different sizes and have different origins in the atmosphere, but at the same time obey the same laws of physics - gradually fall, rotating at the same angular speed for everyone, hover motionlessly or oscillate harmoniously.
Arcs or circles forming a halo appear at a certain distance from the luminary, equidistant from the light source. Sometimes, in addition to a circle or its segments (arcs), a second one appears, located further than the first, but always at the same distance from the luminary. On these arcs and circles there may be bright spots of light - false suns or false moons. There are several of them, but they all always stand at the same height above the horizon as the star itself, and sometimes even opposite it, on the other side of the sky.
Refraction of light in the sky
If you rely on statistics of observations of the halo phenomenon in the sky, we can conclude that the appearance of a halo is characteristic of cirrostratus clouds, in which sunlight is refracted, reflected and scattered in a complex way in small crystals - hexagonal ice prisms, pyramids, columns or plates. Thanks to the optical properties of these crystals, which have a more regular structure than water droplets, the halo looks much more picturesque than halos and crowns. Often, cirrostratus clouds herald the approach of an atmospheric front, so the appearance of a halo can predict worsening weather.
When the sun's rays pass through cirrostratus clouds, which consist of glacial crystals, light oblique crosses, arcs, additional (false) suns, luminous pillars from the horizon to the luminary and other pictures resembling certain objects may appear in the sky. Such phenomena were called “halos” in Russian chronicles, and now they are called solar halo.
Previously in humans the appearance of a halo in the sky caused fear and panic - they seemed like bloody swords and were interpreted as harbingers of great trouble - the start of war, famine, epidemic, etc.
On the other hand, changes in the weather, on the eve of which halos often appear in the sky, are also an unpleasant thing, especially when it comes to natural disasters.
Shapes and types of halo
The shape of the halo depends on the position of the crystals relative to each other when falling in the atmosphere, when they experience atmospheric braking and take a position at which the greatest air resistance is created. however, Brownian motion and atmospheric fluctuations interfere with this, causing small crystals to be randomly distributed in the cloud, while large columnar crystals and platelets are more susceptible to atmospheric drag due to their surface area, so they fall in an oriented manner.
Halo shapes
- Halos can most often be seen in the form circle painted with all the colors of the rainbow around the sun with an angular radius of 22°.
- Slightly less common halo in the form of concentric circles with it a second circle with an angular radius of 22° and 46°.
- And it's very rare Hevelius halo– circle 90°.
- Sometimes you can watch white horizontal circle(parhelic circle), parallel to the horizon plane and passing through the sun. At the intersection of this circle with the halo circles of 22° and 46°, bright rainbow spots appear - false suns ( parhelia), as well as false moons ( parselines).
- It also happens that only visible lower halves of the halo, and also elliptical halo. Among these unusual forms there are rainbows curved in the opposite direction. Most likely these are the lower parts of the 46° or 90° halo circles.
Types of halo
| According to the shape and orientation of the crystals | Randomly oriented crystals, Horizontally oriented columnar crystals, Horizontal prisms, Flat plates, Chaotic and oriented pyramidal crystals |
| By color | White, Colorless, Iridescent incomplete (red, orange and white), Rainbow full (the whole spectrum of colors is visible) |
| By distance from the luminary | Halo of parallel rays (from the sun, moon and some bright celestial bodies), Halo of diverging rays (halo from lanterns and spotlights) |
| Location | Close to the star (22° halo, elliptical halos, parhelia and some others), At a medium distance (46° halo and Lowitz arcs, near-horizontal arc, 90° halo), Encompassing the entire sky (parhelic circle and Hastings arc), In the part of the sky opposite to the luminary (120° parhelia, Wegner arcs, antisun and others), Reflected (subsun, subparhelia and others) |
Where and when can you see a halo
More often halo can be seen in Antarctica on its ice dome and on the slopes located at an altitude of 2700-3500 m above sea level. There they can be observed throughout the whole day, while their shape and color may change. Constant strong winds lift clouds of loose snow with a crystalline structure into the air. The lower boundary of such snow clouds descends all the way to the ground, creating ideal conditions for the formation of a halo. In the absence of snow clouds and in bright sunlight, numerous colored and white halos with a radius of 22° and 46° occur, as well as rarer other phenomena.
Air saturated with moisture tends to crystallize when cooled. When large volumes of moist air masses are transported in the upper layers of the atmosphere over the continent, moisture condensation, crystallization and frost formation occur. During the warm season, ice crystals do not reach the surface of the earth and dissolve in the lower layers of the atmosphere, again saturating the air with moisture. Therefore, the halo phenomenon is more likely to be observed on the continental part of the continents than near the coast.
Sometimes, in frosty weather, a halo forms near the earth's surface, and ice crystals in the air sparkle like precious stones, enhancing the radiance of the halo. If the sun is low above the horizon, the lower part of the halo can sometimes be seen against the background of the surrounding landscape.
Our observations of halo in the sky
We have seen this phenomenon many times, but not every time we had a camera with us. But we especially remember two cases: when we were driving along the Dmitrovskoye Highway towards Moscow, and a spectacular solar phenomenon accompanied us almost the entire trip. And on another sunny day in Pai in Northern Thailand, we saw a very beautiful circle of light in a clear sky.
Halo in the photo
Halo in Thailand, Pai city
why is there a big circle around the moon? and got the best answer
Answer from Yika[guru]
Ring around the Moon
Have you ever seen a large ghostly white ring around the Moon at night?
Circles around the Moon can be confusing at first. We know that in reality there are no rings around the Moon, rotating in outer space at a distance of about 402,250 km from the Earth. But why then do we see a ring around the Moon? And why does it appear occasionally, and not every night?
These rings are just an optical effect, a gift from our atmosphere. If you look closely, you will see that the ring is not actually white. It looks more like a dim, round rainbow with a light red interior and a pale blue exterior.
The ring around the Moon, also known as a halo, appears when light is refracted by ice crystals in high, cold cirrus clouds. Each hexagonal ice crystal acts like a tiny prism. Ice crystals capture rays of white light and refract it, breaking it down into all the colors of the spectrum.
We see refracted moonlight in the shape of a circle because the crystals collect the light into a cone. (You are the observer and are at the apex of this cone.) If you extend both arms forward, the width of the ring will usually be the size of two of your fists. In general, it depends on the amount of light captured by the crystals. Most of the moonlight is captured and refracted at an angle of 22°, forming a small cone. But there are also larger halos, with an angle of 46°, although not so often. These halos form when moonlight passes through the sharper edges of the crystals.
They say that a halo around the Moon foretells rain, and this is often true, since it only appears on a cloudy night.
And what’s surprising is that this companion could also have a twin brother at the same time.
Here's how scientists think it could have happened. In the destructive race that then unfolded in our Universe, rock fragments circled around the newborn Sun, causing numerous terrible collisions. New planets flew into each other, pieces broke off from some astronomical bodies. This chaos continued for millions of years. And when everything finally calmed down, the solar system was formed. Now nine planets, more than 50 satellites and thousands of asteroids, meteorites, meteorites and comets fly in orbit around the Sun.
Our Moon may have had a dramatic, violent birth. The young Earth was very hot - so hot that molten rocks flowed like rivers of lava across its surface. Scientists believe that a small protoplanet, Theia (about the size of Mars), has formed near the surface of the Earth. And naturally, these two planets eventually collided.
At a speed of about 40,000 km/h, the smaller planet crashed into the Earth. As a result of a gigantic explosion, streams of hot liquid lava shot up into space.
Some of this volcanic material returned to Earth, mixed with molten rocks. But most of the escaped material remained in space, forming a lump of hot rocks that flew in orbit around the Earth. Over thousands of years, this lump cooled and rounded, turning into the white-gray Moon that is familiar to us.
Later, when the collision was simulated using a computer program, scientists came to a stunning discovery. In 9 of the 27 simulated scenarios, two satellites formed. One of them, preserved, we call today the Moon; the second satellite had an orbit even closer to the Earth.
Computer models showed how, as a result of the forces of gravity, the orbit of the satellite closest to us became unstable. Less than 100 years later, he fell to the surface of the Earth and disappeared without a trace.
If the theories are correct, then we may be walking through pieces of our moon's former brother every day.
Reply from ANTOM[guru]
Superimposed solar rays falling on the surface of the Moon and rays of sunlight reflected from the surface of the Earth's satellite.
Reply from Evgeny gasnikov[guru]
A halo (large circle) around the Moon means a change in weather (cold weather).
We all remember the lines of Pushkin’s poem “Frost and Sun; wonderful day!” What is so wonderful that you can see in the sky on a frosty, sunny winter morning? One of the “morning miracles” undoubtedly includes the phenomenon of a halo. The photos show what it might look like. Today we will talk about what it is, how such things appear in the sky, when and how it is best to observe it.
What is a halo?
A halo is an optical phenomenon created by tiny ice crystals in the atmosphere. Most often it looks like light circles, arcs, spots and even pillars of light around or near the disks of the Sun and Moon. Halos can also be seen around street lamps, but to create any impressive picture in the sky you need a more powerful light source. Therefore, all the most beautiful halos are observed in daylight or at dusk.
How is a halo formed?
For the fact that we sometimes observe a halo, we must thank a physical phenomenon called light refraction. Everyone has noticed a thousand times that a teaspoon dropped into a glass of water looks bent or even broken at the water-air interface. This happens because light changes its direction slightly when passing from one medium to another. The same thing happens with light when crossing the boundaries of other media, for example, ice crystals. Depending on the orientation of the crystals and the position of the Sun or Moon in the sky, different types of halos can be observed. The simplest halo that is most often observed is the twenty-two degree halo (22⁰ halo). Frozen water crystals floating in the air come in different shapes and sizes, but most often they form regular hexagonal rods of different lengths. All of them are oriented in the air completely randomly.
There are millions of such rod crystals, so there will always be ones whose axes are approximately perpendicular to the rays coming from the Sun (as in the picture).
It turns out that due to the geometric properties of regular hexagons, light passing through one of their faces will be deflected by a small angle ranging from 22 to 27 degrees, which will create a luminous circle around the Sun or Moon.
There are more than one hundred and fifty types of halos, and all of them are classified either by their position in the sky relative to the Sun, or by the name of the person who first described this type of halo. The phenomenon of parhelium stands out here. Parhelium means “false sun” in Latin.
Photo taken in Stockholm
Parhelium is just one type of halo, but it is by far the most impressive. Ice crystals are also responsible for such beauty in frosty weather, only this time not in the form of rods, but in the form of plates. All the ice crystals gradually settle to the surface of the Earth, but they are so light that the falling process can take several hours.
During such a gradual fall, or more precisely, “settling” down, most of the crystal plates line up horizontally. This rather strange behavior for plates is explained by the Bernoulli phenomenon. When the plate falls down, air flows around it from all sides. At the edges of the plate, the air flow speed is higher than in the center, and because of this, the pressure from the edges drops slightly.
It turns out that the air seems to drag the plate horizontally in all directions and prevents it from tilting. The refraction of light in such plates creates what appear to be satellites of the Sun in the sky.
If you are lucky, then the same phenomenon can be seen at night. A false moon, or paraselenium, is also two bright spots that appear to the left and right of the light source - the Moon. Paraselene is formed in the same way as parhelium. However, a false moon is a much rarer phenomenon than a parhelium: a full Moon is required for its appearance. So on frosty evenings, look at the moon more often. If you see paraselena, know that such cases are one in a million.
To give you the right impression of how many halos you can see in the sky at one time, look at this photo.
It was taken by American photographer David Hathaway at the end of October 2012. One photo can fit as many as ten different halos. Vladimir Galynsky simulated observation conditions that could give a similar picture.
Can you see a halo at the equator?
Oddly enough, a halo can be seen even in very hot countries. It may not be as beautiful and impressive as in the middle latitudes or at the North Pole, but you will definitely see a 22-degree halo. The fact is that the halo is formed mainly due to the scattering of light by ice crystals, which are located high, high in the air, where the air temperature is negative.
This photo was taken at 7am in Indonesia, just one degree of latitude from the equator.
How to observe a halo?
Look at the sky more often. Oddly enough, this is the most practical advice for everyone. Even if the sky seems completely clear to you, there may still be a thin layer of clouds forming a halo, invisible at first glance.
First, look for the most common halo- by 22 degrees. By the way, if you stretch out your hand and shade the center of the sun with the end of your thumb, then the protruding little finger should be approximately at a distance of a twenty-two-degree halo. Check if there is a tangent to the large halo (see Galynsky simulation)? Check to see if there is a small, unnoticeable parhelium? If the sun is low on the horizon, look for a skylight.
Look for rare halos. What if you get lucky? The most “common” rare halo is 46 degrees. Halo. Look for it at twice the distance from the sun than 22 degrees. It is believed that in Russia it can be seen 4-8 times a year. Look around yourself to see if there are fragments of the parhelic circle somewhere (it crosses the entire sky). Take a closer look at the area above the sun - what if there is a Parry arc lurking there that you did not notice from the very beginning?
Look for derivatives of visible halos. If you see a bright parhelium, it means there are a lot of flat, hexagonal ice crystals in the air. Such crystals form at 120 degrees. Parhelion.
Look for something unusual. Having seen a large number of different halos in the sky, search the entire sky with your eyes; it is quite possible that you will notice something very rare. Sometimes rare halos appear on their own, without any warning.
Write everything down what they saw in a notepad or phone. Pay special attention to the time accurate to the minute, this will help you later determine the exact height of the sun above the horizon. Take photos. If you don’t have a camera at hand, then at least just sketch what you see, this can also bring a lot of benefits! What if you saw a halo that was only theoretically predicted, but no one has ever seen it?
Walk a hundred or two hundred meters to the side and look at the sky again. A halo is a phenomenon unique to each observation point. Two people of different heights standing next to each other may see different types of halos. This is due to the fact that the ice crystals must be strictly oriented along the line between the observer and the sun. If you step aside, the orientation of the ice crystals in the air relative to you will become different, and you will see something new.
Good luck with your observations!
What about on other planets?
As you understand, not a single person has ever been to other planets in the solar system. Therefore, it may well turn out that in 20 years you will be the first (I wonder if girls read these stories?) to see, and then tell all of humanity what halos on other planets look like. But even now we can figure out something. To do this, you need to know what type of substances can form crystals in the atmosphere of other planets.
Mars
A halo formed by clouds of frozen CO2 and water vapor. The already familiar 22⁰ halo (inner) is surrounded by a 26⁰ halo and a 36⁰ halo, which create carbon dioxide crystals. Unusual parhelia appear.
Jupiter
A halo formed by octahedral ammonia crystals. An octahedron is two pyramids put together at their bases (may mathematicians forgive me). In such crystals, due to their geometric features, light will be refracted differently than in crystals of the water we are familiar with. The halo will be at 42⁰, and double parhelium will accompany it.
Konstantin Kudinov
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A halo is an interesting and unusual natural phenomenon. It appears as a luminous ring or halo around a bright light source. Most often this is the sun, but a similar halo can also be seen around the moon (lunar halo), as well as other bright sources, such as street lamps. There are quite a few different types of halos, but they are based on the same source - ice crystals. These crystals are most often located in cirrus clouds at an altitude of 5-10 km, but they are also found right near the ground. This is when you may see an "aura" around street lights or a halo around someone's head.
The appearance and shape of the halo depends greatly on the shape and arrangement of the crystals, and under some conditions, even parhelium (false sun) can occur. Light passing through ice crystals is refracted and reflected at different angles. The magnitude of this angle depends on the arrangement of the crystals. If the halo is observed in good lighting conditions, then you can see something like a rainbow. In fact, it is simply refracted light decomposed into a spectrum. In low light, the “rainbow” is not visible due to the peculiarities of human vision, although in fact it is there.
Disks around the sun can appear not only as a result of refraction on ice crystals, but also on water droplets that form a cloud or fog. Such discs are called crowns. They can be distinguished from halos by the fact that their radius is much smaller than that of a halo and does not exceed 5%.
I think I won’t surprise anyone if I say that in the past our ancestors endowed the halo around the sun with mystical properties and, most often, considered the appearance of such a miracle in the sky as a bad omen.
A few more photos of the solar halo:
The sun's halo is not necessarily just one halo. There may be several of them.
