What is the milky way briefly. The Milky Way Galaxy: history and main secrets

23.12.2020

Planet Earth, solar system , and all stars visible to the naked eye are in Milky Way Galaxy, which is a barred spiral galaxy with two distinct arms beginning at the ends of the bar.

This was confirmed in 2005 by the Lyman Spitzer Space Telescope, which showed that our galaxy's central bar is larger than previously thought. spiral galaxies barred - spiral galaxies with a bar ("bar") of bright stars, emerging from the center and crossing the galaxy in the middle.

Spiral arms in such galaxies start at the ends of the bars, while in ordinary spiral galaxies they emerge directly from the core. Observations show that about two-thirds of all spiral galaxies are barred. According to existing hypotheses, the bars are centers of star formation that support the birth of stars in their centers. It is assumed that through orbital resonance, they pass gas from the spiral branches through them. This mechanism ensures the flow building material for the birth of new stars. The Milky Way, together with the Andromeda (M31), Triangulum (M33), and over 40 smaller satellite galaxies, form the Local Group of Galaxies, which in turn is part of the Virgo Supercluster. "Using infrared imaging from NASA's Spitzer telescope, scientists have discovered that the Milky Way's elegant spiral structure has only two dominant arms from the ends of the central bar of stars. Our galaxy was previously thought to have four main arms."

/s.dreamwidth.org/img/styles/nouveauoleanders/titles_background.png" target="_blank">http://s.dreamwidth.org/img/styles/nouveauoleanders/titles_background.png) 0% 50% no-repeat rgb(29, 41, 29);"> Structure of the Galaxy
By appearance, the galaxy resembles a disk (because the bulk of the stars are in the form of a flat disk) with a diameter of about 30,000 parsecs (100,000 light years, 1 quintillion kilometers) with an estimated average disk thickness of about 1000 light years, the diameter of the bulge in the center of the disk is 30,000 light years. The disk is immersed in a spherical halo, and around it is a spherical corona. The center of the nucleus of the Galaxy is located in the constellation Sagittarius. The thickness of the galactic disk in the place where it is located solar system with the planet Earth, is 700 light years. The distance from the Sun to the center of the Galaxy is 8.5 kilo parsecs (2.62.1017 km, or 27,700 light years). solar system is located on the inner edge of the arm, which is called the arm of Orion. In the center of the Galaxy, apparently, there is a supermassive black hole (Sagittarius A *) (about 4.3 million solar masses) around which, presumably, a black hole of average mass from 1000 to 10,000 solar masses rotates with an orbital period of about 100 years and several thousand relatively small ones. The galaxy contains, according to the lowest estimate, about 200 billion stars (modern estimates range from 200 to 400 billion). As of January 2009, the mass of the Galaxy is estimated at 3.1012 solar masses, or 6.1042 kg. The main mass of the Galaxy is contained not in stars and interstellar gas, but in a non-luminous halo of dark matter.

Compared to the halo, the disk of the Galaxy rotates noticeably faster. The speed of its rotation is not the same at different distances from the center. It rapidly increases from zero at the center to 200–240 km/s at a distance of 2,000 light-years from it, then decreases somewhat, increases again to approximately the same value, and then remains almost constant. The study of the features of the rotation of the disk of the Galaxy made it possible to estimate its mass, it turned out that it is 150 billion times greater than the mass of the Sun. Age Milky Way galaxy equals13,200 million years old, almost as old as the universe. The Milky Way is part of the Local Group of Galaxies.

/s.dreamwidth.org/img/styles/nouveauoleanders/titles_background.png" target="_blank">http://s.dreamwidth.org/img/styles/nouveauoleanders/titles_background.png) 0% 50% no-repeat rgb(29, 41, 29);"> Solar System Location solar system is located on the inner edge of the arm called the Orion arm, in the outskirts of the Local Supercluster (Local Supercluster), which is sometimes also called the Virgo Supercluster. The thickness of the galactic disk (in the place where it is located solar system with the planet Earth) is 700 light years. The distance from the Sun to the center of the Galaxy is 8.5 kilo parsecs (2.62.1017 km, or 27,700 light years). The sun is located closer to the edge of the disk than to its center.

Together with other stars, the Sun revolves around the center of the Galaxy at a speed of 220-240 km / s, making one revolution in about 225-250 million years (which is one galactic year). Thus, for the entire time of its existence, the Earth flew around the center of the Galaxy no more than 30 times. The galactic year of the Galaxy is 50 million years, the orbital period of the jumper is 15-18 million years. In the vicinity of the Sun, it is possible to track sections of two spiral arms that are about 3 thousand light years away from us. According to the constellations where these areas are observed, they were given the name of the Sagittarius arm and the Perseus arm. The sun is located almost in the middle between these spiral arms. But relatively close to us (by galactic standards), in the constellation of Orion, there is another, not very clearly defined arm - the Orion arm, which is considered an offshoot of one of the main spiral arms of the Galaxy. The speed of rotation of the Sun around the center of the Galaxy almost coincides with the speed of the compression wave that forms the spiral arm. This situation is atypical for the Galaxy as a whole: the spiral arms rotate at a constant angular velocity, like spokes in wheels, and the movement of stars occurs with a different pattern, so almost the entire stellar population of the disk either gets inside the spiral arms or falls out of them. The only place where the speeds of stars and spiral arms coincide is the so-called corotation circle, and it is on this circle that the Sun is located. For the Earth, this circumstance is extremely important, since violent processes occur in the spiral arms, which form powerful radiation that is destructive to all living things. And no atmosphere could protect him from it. But our planet exists in a relatively quiet place in the Galaxy and has not been affected by these cosmic cataclysms for hundreds of millions (or even billions) of years. Perhaps that is why on Earth could be born and survive life, whose age is counted in 4.6 billion years. A diagram of the location of the Earth in the universe in a series of eight maps that show, from left to right, starting from the Earth, moving into solar system, to neighboring star systems, to the Milky Way, to local Galactic groups, tolocal superclusters of Virgo, at our local super cluster, and ends in the observable universe.

Solar system: 0.001 light years

Neighbors in interstellar space

Milky Way: 100,000 light years

Local Galactic Groups

Virgo Local Super Cluster

Local over clusters of galaxies

observable universe

The Milky Way is the galaxy that contains the Earth, the solar system, and all the individual stars visible to the naked eye. Refers to barred spiral galaxies.

The Milky Way, together with the Andromeda Galaxy (M31), the Triangulum Galaxy (M33) and more than 40 dwarf satellite galaxies - its own and Andromeda - form the Local Group of galaxies, which is part of the Local Supercluster (Virgo Supercluster).

Discovery history

Discovery of Galileo

The Milky Way revealed its secret only in 1610. It was then that the first telescope was invented, which was used by Galileo Galilei. The famous scientist saw through the device that the Milky Way is a real cluster of stars, which, when viewed with the naked eye, merged into a continuous faintly twinkling band. Galileo even succeeded in explaining the heterogeneity of the structure of this band. It was caused by the presence in the celestial phenomenon of not only star clusters. There are also dark clouds. The combination of these two elements creates an amazing image of the night phenomenon.

Discovery of William Herschel

The study of the Milky Way continued into the 18th century. During this period, his most active researcher was William Herschel. The famous composer and musician was engaged in the manufacture of telescopes and studied the science of the stars. The most important discovery of Herschel was the Great Plan of the Universe. This scientist observed the planets through a telescope and counted them in different parts of the sky. Studies have led to the conclusion that the Milky Way is a kind of stellar island, in which our Sun is also located. Herschel even drew a schematic plan of his discovery. In the figure, the star system was depicted as a millstone and had an elongated irregular shape. The sun at the same time was inside this ring that surrounded our world. This is how all scientists represented our Galaxy until the beginning of the last century.

It was not until the 1920s that the work of Jacobus Kaptein saw the light of day, in which the Milky Way was described in the most detailed way. At the same time, the author gave a scheme of the star island, which is as similar as possible to the one that is known to us at the present time. Today we know that the Milky Way is a Galaxy, which includes the solar system, the Earth and those individual stars that are visible to humans with the naked eye.

What shape is the Milky Way?

When studying galaxies, Edwin Hubble classified them into various types of elliptical and spiral. Spiral galaxies are disk-shaped with spiral arms inside. Since the Milky Way is disk-shaped along with spiral galaxies, it is logical to assume that it is probably a spiral galaxy.

In the 1930s, R. J. Trumpler realized that the estimates of the size of the Milky Way galaxy made by Kapetin and others were erroneous, because the measurements were based on observations using radiation waves in the visible region of the spectrum. Trumpler came to the conclusion that a huge amount of dust in the plane of the Milky Way absorbs visible light. Therefore, distant stars and their clusters seem more ghostly than they really are. Because of this, in order to accurately image the stars and star clusters within the Milky Way, astronomers had to find a way to see through the dust.

In the 1950s, the first radio telescopes were invented. Astronomers have discovered that hydrogen atoms emit radiation in radio waves, and that such radio waves can penetrate dust in the Milky Way. Thus, it became possible to see the spiral arms of this galaxy. To do this, we used the marking of stars by analogy with marks when measuring distances. Astronomers realized that O and B stars could serve to achieve this goal.

Such stars have several features:

brightness– they are highly visible and often found in small groups or associations;
heat– they emit waves of different lengths (visible, infrared, radio waves);
short life time They live for about 100 million years. Given the speed at which stars rotate at the center of the galaxy, they do not move far from their birthplace.

Astronomers can use radio telescopes to accurately match the positions of O and B stars and, based on the Doppler shifts in the radio spectrum, determine their speed. After performing such operations on many stars, scientists were able to produce combined radio and optical maps of the Milky Way's spiral arms. Each arm is named after the constellation that exists in it.

Astronomers believe that the movement of matter around the center of the galaxy creates density waves (regions of high and low density), just like you see when you mix cake dough with an electric mixer. These density waves are thought to have caused the spiral character of the galaxy.

Thus, by examining the sky at different wavelengths (radio, infrared, visible, ultraviolet, X-ray) using various ground-based and space telescopes, one can obtain various images of the Milky Way.

Doppler effect. Just as the high pitched sound of a fire truck siren gets lower as the vehicle moves away, the movement of the stars affects the wavelengths of light that reach Earth from them. This phenomenon is called the Doppler effect. We can measure this effect by measuring the lines in the star's spectrum and comparing them to the spectrum of a standard lamp. The degree of Doppler shift indicates how fast the star is moving relative to us. In addition, the direction of the Doppler shift can show us the direction in which the star is moving. If the star's spectrum shifts to the blue end, then the star is moving towards us; if in the red direction, it moves away.

Structure of the Milky Way

If we carefully consider the structure of the Milky Way, we will see the following:

galactic disk. Most of the stars in the Milky Way are concentrated here.

The disk itself is divided into the following parts:

The nucleus is the center of the disk;
Arcs - areas around the nucleus, including directly the areas above and below the plane of the disk.
Spiral arms are areas that protrude outward from the center. Our solar system is located in one of the spiral arms of the Milky Way.

globular clusters. Several hundred of them are scattered above and below the plane of the disk.
Halo. This is a large, dim region that surrounds the entire galaxy. The halo consists of high temperature gas and possibly dark matter.

The radius of the halo is much larger than the size of the disk and, according to some data, reaches several hundred thousand light-years. The center of symmetry of the Milky Way halo coincides with the center of the galactic disk. The halo consists mainly of very old, dim stars. The age of the spherical component of the Galaxy exceeds 12 billion years. The central, densest part of the halo within a few thousand light-years of the center of the Galaxy is called bulge(translated from English "thickening"). The halo as a whole rotates very slowly.

Compared to halo disk spins much faster. It looks like two plates folded at the edges. The diameter of the disk of the Galaxy is about 30 kpc (100,000 light years). The thickness is about 1000 light years. The rotation speed is not the same at different distances from the center. It rapidly increases from zero in the center to 200-240 km/s at a distance of 2 thousand light years from it. The mass of the disk is 150 billion times the mass of the Sun (1.99*1030 kg). Young stars and star clusters are concentrated in the disk. There are many bright and hot stars among them. The gas in the disk of the Galaxy is unevenly distributed, forming giant clouds. Main chemical element in our galaxy is hydrogen. About 1/4 of it consists of helium.

One of the most interesting regions of the Galaxy is its center, or core located in the direction of the constellation Sagittarius. The visible radiation of the central regions of the Galaxy is completely hidden from us by powerful layers of absorbing matter. Therefore, it began to be studied only after the creation of receivers for infrared and radio radiation, which is absorbed to a lesser extent. The central regions of the Galaxy are characterized by a strong concentration of stars: there are many thousands of them in each cubic parsec. Closer to the center, regions of ionized hydrogen and numerous sources of infrared radiation are noted, indicating star formation taking place there. At the very center of the Galaxy, the existence of a massive compact object is assumed - a black hole with a mass of about a million solar masses.

One of the most notable formations is spiral branches (or sleeves). They gave the name to this type of objects - spiral galaxies. Along the arms, the youngest stars are mainly concentrated, many open star clusters, as well as chains of dense clouds of interstellar gas in which stars continue to form. In contrast to the halo, where any manifestations of stellar activity are extremely rare, a stormy life continues in the branches, associated with the continuous transition of matter from interstellar space to stars and back. The spiral arms of the Milky Way are largely hidden from us by absorbing matter. Their detailed study began after the advent of radio telescopes. They made it possible to study the structure of the Galaxy by observing the radio emission of interstellar hydrogen atoms, which are concentrated along long spirals. By modern ideas, spiral arms are associated with compression waves propagating across the disk of the galaxy. Passing through the compression regions, the matter of the disk becomes denser, and the formation of stars from the gas becomes more intense. The reasons for the appearance of such a peculiar wave structure in the disks of spiral galaxies are not entirely clear. Many astrophysicists are working on this problem.

The place of the sun in the galaxy

In the vicinity of the Sun, it is possible to trace sections of two spiral branches that are about 3 thousand light years away from us. According to the constellations where these areas are found, they are called the Sagittarius arm and the Perseus arm. The sun is almost in the middle between these spiral arms. True, relatively close (by galactic standards) from us, in the constellation of Orion, there is another, not so pronounced branch, which is considered an offshoot of one of the main spiral arms of the Galaxy.

The distance from the Sun to the center of the Galaxy is 23-28 thousand light years, or 7-9 thousand parsecs. This suggests that the Sun is located closer to the edge of the disk than to its center.

Together with all nearby stars, the Sun revolves around the center of the Galaxy at a speed of 220–240 km/s, making one revolution in about 200 million years. This means that for the entire time of its existence, the Earth flew around the center of the Galaxy no more than 30 times.

The speed of rotation of the Sun around the center of the Galaxy practically coincides with the speed with which the compression wave, which forms the spiral arm, moves in the given region. Such a situation is generally unusual for the Galaxy: the spiral arms rotate at a constant angular velocity, like the spokes of a wheel, while the movement of stars, as we have seen, obeys a completely different pattern. Therefore, almost the entire stellar population of the disk either gets inside the spiral branch or leaves it. The only place where the speeds of stars and spiral arms coincide is the so-called corotation circle, and it is on it that the Sun is located!

For the Earth, this circumstance is extremely favorable. After all, violent processes occur in the spiral branches, generating powerful radiation, destructive for all living things. And no atmosphere could protect him from it. But our planet exists in a relatively quiet place in the Galaxy and has not experienced the influence of these cosmic cataclysms for hundreds of millions and billions of years. Perhaps that is why life could originate and survive on Earth.

For a long time, the position of the Sun among the stars was considered the most ordinary. Today we know that this is not the case: in in a certain sense it is privileged. And this must be taken into account when discussing the possibility of the existence of life in other parts of our Galaxy.

The location of the stars

On a cloudless night sky, the Milky Way is visible from anywhere on our planet. However, only a part of the Galaxy, which is a system of stars located inside the Orion arm, is accessible to the human eye. What is the Milky Way? The definition in space of all its parts becomes most understandable if we consider the star map. In this case, it becomes clear that the Sun, illuminating the Earth, is located almost on the disk. This is almost the edge of the Galaxy, where the distance from the nucleus is 26-28 thousand light years. Moving at a speed of 240 kilometers per hour, the Luminary spends 200 million years on one revolution around the core, so that for the entire time of its existence it traveled across the disk, rounding the core, only thirty times. Our planet is in the so-called corotation circle. This is a place in which the speed of rotation of the arms and stars are identical. For this circle typical elevated level radiation. That is why life, as scientists believe, could only arise on that planet, near which there is a small number of stars. Our Earth is such a planet. It is located on the periphery of the Galaxy, in its most peaceful place. That is why on our planet for several billion years there were no global cataclysms that often occur in the Universe.

What will the death of the Milky Way look like?

The cosmic story of the death of our galaxy begins here and now. We can blindly look around, thinking that the Milky Way, Andromeda (our older sister) and a bunch of unknowns - our cosmic neighbors - this is our home, but in reality there is much more. It's time to explore what else is around us. Go.

Triangulum Galaxy. With a mass of about 5% of that of the Milky Way, it is the third largest galaxy in the Local Group. It has a spiral structure, its own satellites and may be a satellite of the Andromeda galaxy.
Large Magellanic Cloud. This galaxy is only 1% of the mass of the Milky Way, but is the fourth largest in our local group. It is very close to our Milky Way—less than 200,000 light-years away—and is undergoing active star formation as tidal interactions with our galaxy cause gas to collapse and create new, hot, and big stars in the Universe.
Small Magellanic Cloud, NGC 3190 and NGC 6822. All of them have masses from 0.1% to 0.6% of the Milky Way (and it is not clear which one is larger) and all three are independent galaxies. Each contains over a billion solar masses of material.
Elliptical galaxies M32 and M110. They may be "only" satellites of Andromeda, but each of them has more than a billion stars, and they can even exceed the masses of numbers 5, 6 and 7.

In addition, there are at least 45 other known galaxies - smaller ones - that make up our local group. Each of them has a halo of dark matter surrounding it; each of them is gravitationally attached to the other, located at a distance of 3 million light years. Despite their size, mass and size, none of them will remain in a few billion years.

So the main thing

As time passes, galaxies interact gravitationally. They not only pull together due to gravitational attraction, but also interact tidally. We usually talk about tides in the context of the Moon pulling on Earth's oceans and creating tides, and this is partly true. But from the point of view of the galaxy, the tides are a less noticeable process. The part of the small galaxy that is close to the big one will be attracted with more gravitational force, and the part that is further away will experience less attraction. As a result, the small galaxy will stretch out and eventually break apart under the influence of gravity.

Not large galaxies, which are part of our local group, including both Magellanic clouds and dwarf elliptical galaxies, will be torn apart in this way, and their material will be included in the large galaxies with which they merge. “So what,” you say. After all, this is not quite death, because large galaxies will remain alive. But even they will not exist forever in this state. In 4 billion years, the mutual gravitational pull of the Milky Way and Andromeda will drag the galaxies into a gravitational dance that will lead to a big merger. Although this process will take billions of years, the spiral structure of both galaxies will be destroyed, resulting in the creation of a single, giant elliptical galaxy at the core of our local group: the Milkweeds.

A small percentage of the stars will be ejected during such a merger, but the majority will remain unharmed, and there will be a large burst of star formation. Eventually, the rest of the galaxies in our local group will also be sucked in, leaving one big giant galaxy to gobble up the rest. This process will take place in all related groups and clusters of galaxies throughout the universe, while dark energy will push individual groups and clusters apart from each other. But even this cannot be called death, because the galaxy will remain. And for a while it will be. But the galaxy is made up of stars, dust and gas, and everything will eventually come to an end.

Across the Universe, galactic mergers will take place over tens of billions of years. During the same time, dark energy will pull them all over the Universe to a state of complete solitude and inaccessibility. And although the last galaxies outside our local group will not disappear until hundreds of billions of years have passed, the stars in them will live. The longest-lived stars in existence today will continue to burn their fuel for tens of trillions of years, and new stars will emerge from the gas, dust, and stellar corpses that populate each galaxy—albeit with fewer and fewer.

When the last stars burn out, only their corpses will remain - white dwarfs and neutron stars. They will shine for hundreds of trillions or even quadrillions of years before they go out. When that inevitability happens, we're left with brown dwarfs (failed stars) that accidentally fuse, re-ignite nuclear fusion, and create starlight for tens of trillions of years.

When the last star goes out tens of quadrillion years in the future, there will still be some mass left in the galaxy. So this can not be called "true death."

All masses gravitationally interact with each other, and gravitational objects of different masses exhibit strange properties when interacting:

Repeated "approaches" and close passes cause exchanges of speed and momentum between them.
Objects with low mass are ejected from the galaxy, and objects with higher mass sink into the center, losing speed.
Over a sufficiently long period of time, most of masses will be ejected, and only a small part of the remaining masses will be rigidly tied.

At the very center of these galactic remnants will be a supermassive black hole, in every galaxy, and the rest of the galactic objects will orbit a larger version of our own solar system. Of course, this structure will be the last, and since the black hole will be as large as possible, it will eat everything it can reach. At the center of Mlecomeda there will be an object hundreds of millions of times more massive than our Sun.

But will it end too?

Thanks to the phenomenon of Hawking radiation, even these objects will one day decay. It will take about 10 80 to 10 100 years, depending on how massive our supermassive black hole becomes as it grows, but the end is coming. After that, the remains, rotating around the galactic center, will untie and leave only a halo of dark matter, which can also randomly dissociate, depending on the properties of this very matter. Without any matter, there will be nothing that we once called the local group, the Milky Way and other dear names.

Mythology

Armenian, Arabic, Wallachian, Jewish, Persian, Turkish, Kyrgyz

According to one of the Armenian myths about the Milky Way, the god Vahagn, the ancestor of the Armenians, stole straw from the ancestor of the Assyrians, Barsham, in a harsh winter and disappeared into the sky. When he walked with his prey across the sky, he dropped straws on his way; from them a light trail was formed in the sky (in Armenian “Straw thief’s road”). The myth about scattered straw is also spoken of by Arabic, Jewish, Persian, Turkish and Kyrgyz names (Kirg. samanchynyn jolu- the path of the strawman) of this phenomenon. The inhabitants of Wallachia believed that Venus stole this straw from St. Peter.

Buryat

According to Buryat mythology, good forces create the world, change the universe. Thus, the Milky Way arose from the milk that Manzan Gurme drew from her breast and splashed out after Abai Geser, who had deceived her. According to another version, the Milky Way is a "seam of the sky" sewn up after the stars fell out of it; on it, like on a bridge, tengri walk.

Hungarian

According to Hungarian legend, Attila will descend the Milky Way if the Székelys are in danger; the stars represent sparks from the hooves. Milky Way. accordingly, it is called the "road of warriors."

ancient greek

Etymology of the word Galaxias (Γαλαξίας) and its association with milk (γάλα) reveal two similar ancient Greek myths. One of the legends tells about the mother's milk spilled across the sky of the goddess Hera, who was breastfeeding Hercules. When Hera learned that the baby she was breastfeeding was not her own child, but the illegitimate son of Zeus and an earthly woman, she pushed him away, and the spilled milk became the Milky Way. Another legend says that the spilled milk is the milk of Rhea, the wife of Kronos, and Zeus himself was the baby. Kronos devoured his children, as it was predicted to him that he would be overthrown by his own son. Rhea has a plan to save her sixth child, the newborn Zeus. She wrapped a stone in baby clothes and slipped it to Kronos. Kronos asked her to feed her son one more time before he swallowed him. The milk spilled from Rhea's chest on a bare rock was subsequently called the Milky Way.

Indian

The ancient Indians considered the Milky Way to be the milk of an evening red cow passing through the sky. In the Rig Veda, the Milky Way is called Aryaman's Throne Road. The Bhagavata Purana contains a version according to which the Milky Way is the belly of a celestial dolphin.

Inca

The main objects of observation in Inca astronomy (which is reflected in their mythology) in the sky were the dark sections of the Milky Way - a kind of "constellation" in the terminology of Andean cultures: Lama, Lama Cub, Shepherd, Condor, Partridge, Toad, Snake, Fox; as well as the stars: the Southern Cross, the Pleiades, Lyra and many others.

Ketskaya

In the Ket myths, similarly to the Selkup ones, the Milky Way is described as the road of one of the three mythological characters: the Son of Heaven (Esya), who went hunting to the western side of the sky and froze there, the hero Albe, who pursued the evil goddess, or the first shaman Dokh, who climbed this road to the sun.

Chinese, Vietnamese, Korean, Japanese

In the mythologies of the Sinosphere, the Milky Way is called and compared with a river (in Vietnamese, Chinese, Korean and Japanese, the name “silver river” is retained. The Chinese also sometimes called the Milky Way “Yellow Road”, according to the color of straw.

Indigenous peoples of North America

The Hidatsa and the Eskimos call the Milky Way "Ash". Their myths speak of a girl who scattered ashes across the sky so that people could find their way home at night. The Cheyenne believed that the Milky Way was dirt and silt raised by the belly of a turtle floating in the sky. Eskimos from the Bering Strait - that these are the traces of the Creator Raven walking across the sky. The Cherokee believed that the Milky Way was formed when one hunter stole another's wife out of jealousy, and her dog began to eat unattended cornmeal and scattered it across the sky (the same myth is found among the Khoisan population of the Kalahari). Another myth of the same people says that the Milky Way is the trail of a dog dragging something across the sky. The Ctunah called the Milky Way "the dog's tail", the Blackfoot called it the "wolf road". Wyandot myth says that the Milky Way is a place where the souls of dead people and dogs come together and dance.

Maori

In Maori mythology, the Milky Way is considered to be the Tama-rereti boat. The nose of the boat is the constellation Orion and Scorpio, the anchor is the Southern Cross, Alpha Centauri and Hadar are the rope. According to legend, one day Tama-rereti was sailing in his canoe and saw that it was already late, and he was far from home. There were no stars in the sky, and, fearing that Tanif might attack, Tama-rereti began to throw sparkling pebbles into the sky. The heavenly deity Ranginui liked what he was doing, and he placed the Tama-rereti boat in the sky, and turned the pebbles into stars.

Finnish, Lithuanian, Estonian, Erzya, Kazakh

The Finnish name is Fin. Linnunrata- means "The Way of the Birds"; the Lithuanian name has a similar etymology. Estonian myth also connects the Milky ("bird's") Way with bird flight.

The Erzya name is "Kargon Ki" ("Crane Road").

The Kazakh name is “Kus Zholy” (“Way of the Birds”).

Interesting facts about the Milky Way galaxy

The Milky Way began forming as a cluster of dense regions after big bang. The first stars to appear were in globular clusters that continue to exist. These are the oldest stars in the galaxy;
The galaxy has increased its parameters by absorbing and merging with others. Now she is picking stars from the Sagittarius Dwarf Galaxy and the Magellanic Clouds;
The Milky Way moves in space with an acceleration of 550 km / s with respect to the background radiation;
Lurking at the galactic center is the supermassive black hole Sagittarius A*. By mass, it is 4.3 million times greater than the solar one;
Gas, dust and stars revolve around the center at a speed of 220 km/s. This is a stable indicator, implying the presence of a shell of dark matter;
In 5 billion years, a collision with the Andromeda galaxy is expected.

In our century, illuminated by hundreds of electric lights, the inhabitants of the city do not have the opportunity to see the Milky Way. This phenomenon, which occurs in our sky only at a certain period of the year, is observed only far from large settlements. In our latitudes, it is especially beautiful in August. In the last month of summer, the Milky Way rises above the Earth in the form of a giant celestial arch. This weak, blurred strip of light looks denser and brighter in the direction of Scorpio and Sagittarius, and paler and more diffuse - near Perseus.

star riddle

The Milky Way is an unusual phenomenon, the secret of which has not been revealed to people for a whole string of centuries. In the legends and myths of many peoples, it was called differently. The amazing glow was the mysterious Star Bridge leading to heaven, the Road of the Gods and the magical Heavenly River carrying divine milk. At the same time, all peoples believed that the Milky Way is something sacred. The radiance was worshipped. Temples were built in honor of him.

Few people know that our New Year tree is an echo of the cults of people who lived in the old days. Indeed, in ancient times it was believed that the Milky Way is the axis of the Universe or the World Tree, on the branches of which stars ripen. That is why at the beginning of the annual cycle they decorated the Christmas tree. The earthly tree was an imitation of the eternally fruitful tree of heaven. Such a ritual gave hope for the favor of the gods and a good harvest. So great was the significance of the Milky Way for our ancestors.

scientific assumptions

What is the Milky Way? The history of the discovery of this phenomenon has almost 2000 years. Even Plato called this strip of light a seam connecting the celestial hemispheres. In contrast, Anaxagoras and Demoxides argued that the Milky Way (which color, we will consider) is a kind of illumination of the stars. She is the decoration of the night sky. Aristotle explained that the Milky Way is a radiance in the air of our planet of luminous circumlunar vapors.

There were many other speculations as well. So, the Roman Mark Manilius said that the Milky Way is a constellation of small celestial bodies. It was he who was closest to the truth, but he could not confirm his assumptions in those days when the sky was observed only with the naked eye. All ancient researchers believed that the Milky Way is part of the solar system.

Discovery of Galileo

It was caused by the presence in the celestial phenomenon of not only star clusters. There are also dark clouds. The combination of these two elements creates an amazing image of the night phenomenon.

Discovery of William Herschel

The structure of galaxies

With the development of science, astronomical telescopes became more powerful and more powerful. At the same time, the structure of the observed galaxies became clearer. It turns out they don't look alike. Some of them were wrong. Their structure was not symmetrical.

Elliptical and spiral galaxies have also been observed. To which of these types does the Milky Way belong? This is our Galaxy, and being inside, it is very difficult to determine its structure. However, scientists have found the answer to this question. Now we know what the Milky Way is. Its definition was given by researchers who found that it is a disk that has an inner core.

general characteristics

The Milky Way is a spiral galaxy. At the same time, it has a jumper in the form of a huge star system, interconnected by gravitational forces.

The Milky Way is believed to have been in existence for over thirteen billion years. This is the period during which about 400 billion constellations and stars, more than a thousand huge gas nebulae, clusters and clouds formed in this Galaxy.

The shape of the Milky Way is clearly visible on the map of the Universe. Upon examination, it becomes clear that this cluster of stars is a disk with a diameter of 100 thousand light years (one such light year is ten trillion kilometers). Thickness - 15 thousand, and depth - about 8 thousand light years.

How much does the Milky Way weigh? This (determining its mass is a very difficult task) cannot be calculated. It is difficult to determine the mass of dark matter that does not interact with electromagnetic radiation. This is why astronomers cannot definitively answer this question. But there are rough estimates, according to which the weight of the Galaxy is in the range from 500 to 3000 billion solar masses.

The Milky Way is like all celestial bodies. It makes revolutions around its axis, moving in the Universe. Astronomers point to the uneven, even chaotic movement of our galaxy. This is explained by the fact that each of its constituent nebulae has its own speed, different from the others, as well as different forms and types of orbits.

What are the parts of the Milky Way? These are the core and bridges, the disk and spiral arms, as well as the crown. Let's consider them in more detail.

Core

This part of the Milky Way is located in the core. There is a source of non-thermal radiation with a temperature of about ten million degrees. In the center of this part of the Milky Way is a seal called the "bulge". This is a whole string of old stars that moves in an elongated orbit. Most of these celestial bodies life cycle is coming to an end.

In the central part of the core of the Milky Way is located This section of outer space, the weight of which is equal to the mass of three million suns, has a powerful gravity. Another black hole revolves around it, only smaller. Such a system creates something so strong that nearby constellations and stars move along very unusual trajectories.

The center of the Milky Way has other features as well. So, it is characterized by a large cluster of stars. Moreover, the distance between them is hundreds of times less than that observed on the periphery of the formation.

It is also interesting that, when observing the nuclei of other galaxies, astronomers note their bright radiance. But why is it not visible in the Milky Way? Some researchers have even suggested that there is no nucleus in our Galaxy. However, it has been determined that dark layers exist in spiral nebulae, which are interstellar accumulations of dust and gas. They also exist in the Milky Way. These huge dark clouds do not allow the earthly observer to see the radiance of the core. If such a formation did not interfere with earthlings, then we could observe the core in the form of a shining ellipsoid, the size of which would exceed the diameter of a hundred moons.

Modern telescopes, which are capable of operating in special ranges of the electromagnetic radiation spectrum, helped people answer this question. With this state-of-the-art technology that was able to bypass the dust shield, scientists were able to see the core of the Milky Way.

Jumper

This element of the Milky Way crosses its central section and has a size of 27 thousand light years. The jumper consists of 22 million red stars with an impressive age. Around this formation is a gas ring, which contains a large percentage of molecular oxygen. All this suggests that the bar of the Milky Way is the area where the largest number of stars are formed.

Disk

This is the shape of the Milky Way itself, which is in constant rotary motion. Interestingly, the rate of this process depends on the distance of one or another region from the nucleus. So, in the very center it is equal to zero. At a distance of two thousand light years from the core, the rotation speed is 250 kilometers per hour.

Surrounding the outer side of the Milky Way is a layer of atomic hydrogen. Its thickness is 1.5 thousand light years.

On the outskirts of the Galaxy, astronomers have discovered the presence of dense accumulations of gas with a temperature of 10 thousand degrees. The thickness of such formations is several thousand light years.

Five spiral arms

This is another component of the Milky Way, located directly behind the gas ring. Spiral arms cross the constellations Cygnus and Perseus, Orion and Sagittarius, and Centaurus. These formations are unevenly filled with molecular gas. Such a composition introduces errors into the rules for the rotation of the Galaxy.
Spiral arms emerge directly from the core of the stellar island. We observe them with the naked eye, calling the bright band the Milky Way.

Spiral branches are projected onto each other, which makes it difficult to understand their structure. Scientists suggest that such arms were formed due to the presence in the Milky Way of giant waves of rarefaction and compression of interstellar gas, which move from the core to the galactic disk.

Crown

The Milky Way has a spherical halo. This is his crown. This education consists of individual stars and clusters of constellations. Moreover, the dimensions of the spherical halo are such that it goes beyond the boundaries of the Galaxy by 50 light years.

As a rule, the Milky Way's corona contains low-mass and old stars, as well as dwarf galaxies and accumulations of hot gas. All these components produce movement in elongated orbits around the nucleus, making random rotation.

There is a hypothesis according to which the appearance of the corona was the result of the absorption of small galaxies by the Milky Way. According to astronomers, the age of the halo is about twelve billion years.

The location of the stars

What is the Milky Way? The definition in space of all its parts becomes most understandable if we consider the star map. In this case, it becomes clear that the Sun, illuminating the Earth, is located almost on the disk. This is almost the edge of the Galaxy, where the distance from the nucleus is 26-28 thousand light years. Moving at a speed of 240 kilometers per hour, the Luminary spends 200 million years on one revolution around the core, so that for the entire time of its existence it traveled across the disk, rounding the core, only thirty times.

Our planet is in the so-called corotation circle. This is a place in which the speed of rotation of the arms and stars are identical. This circle is characterized by an increased level of radiation. That is why life, as scientists believe, could only arise on that planet, near which there is a small number of stars.

Our Earth is such a planet. It is located on the periphery of the Galaxy, in its most peaceful place. That is why on our planet for several billion years there were no global cataclysms that often occur in the Universe.

Forecast for the future

Scientists suggest that in the future, collisions between the Milky Way and other galaxies are very likely, the largest of which is the Andromeda galaxy. But at the same time, it is not possible to talk specifically about anything. This requires knowledge of the transverse velocities of extragalactic objects, which are not yet available to modern researchers.

In September 2014, one of the models for the development of events was published in the media. According to her, four billion years will pass, and the Milky Way will absorb the Magellanic clouds (Large and Small), and in another billion years it will itself become part of the Andromeda Nebula.

The Milky Way is the galaxy that contains the Earth, the solar system, and all the individual stars visible to the naked eye. Refers to barred spiral galaxies.

Discovery history

Discovery of Galileo

Discovery of William Herschel

What shape is the Milky Way?

Such stars have several features:

brightness– they are highly visible and often found in small groups or associations;
heat– they emit waves of different lengths (visible, infrared, radio waves);
short life time They live for about 100 million years. Given the speed at which stars rotate at the center of the galaxy, they do not move far from their birthplace.

Thus, by examining the sky at different wavelengths (radio, infrared, visible, ultraviolet, X-ray) using various ground-based and space telescopes, one can obtain various images of the Milky Way.

Doppler effect. Just as the high pitched sound of a fire truck siren gets lower as the vehicle moves away, the movement of the stars affects the wavelengths of light that reach Earth from them. This phenomenon is called the Doppler effect. We can measure this effect by measuring the lines in the star's spectrum and comparing them to the spectrum of a standard lamp. The degree of Doppler shift indicates how fast the star is moving relative to us. In addition, the direction of the Doppler shift can show us the direction in which the star is moving. If the star's spectrum shifts to the blue end, then the star is moving towards us; if in the red direction, it moves away.

Structure of the Milky Way

If we carefully consider the structure of the Milky Way, we will see the following:

galactic disk. Most of the stars in the Milky Way are concentrated here.

The disk itself is divided into the following parts:

The nucleus is the center of the disk;
Arcs - areas around the nucleus, including directly the areas above and below the plane of the disk.
Spiral arms are areas that protrude outward from the center. Our solar system is located in one of the spiral arms of the Milky Way.

globular clusters. Several hundred of them are scattered above and below the plane of the disk.
Halo. This is a large, dim region that surrounds the entire galaxy. The halo consists of high temperature gas and possibly dark matter.

Compared to halo disk spins much faster. It looks like two plates folded at the edges. The diameter of the disk of the Galaxy is about 30 kpc (100,000 light years). The thickness is about 1000 light years. The rotation speed is not the same at different distances from the center. It rapidly increases from zero in the center to 200-240 km/s at a distance of 2 thousand light years from it. The mass of the disk is 150 billion times the mass of the Sun (1.99*1030 kg). Young stars and star clusters are concentrated in the disk. There are many bright and hot stars among them. The gas in the disk of the Galaxy is unevenly distributed, forming giant clouds. Hydrogen is the main chemical element in our Galaxy. About 1/4 of it consists of helium.

One of the most notable formations is spiral branches (or sleeves). They gave the name to this type of objects - spiral galaxies. Along the arms, the youngest stars are mainly concentrated, many open star clusters, as well as chains of dense clouds of interstellar gas in which stars continue to form. In contrast to the halo, where any manifestations of stellar activity are extremely rare, a stormy life continues in the branches, associated with the continuous transition of matter from interstellar space to stars and back. The spiral arms of the Milky Way are largely hidden from us by absorbing matter. Their detailed study began after the advent of radio telescopes. They made it possible to study the structure of the Galaxy by observing the radio emission of interstellar hydrogen atoms, which are concentrated along long spirals. According to modern concepts, spiral arms are associated with compression waves propagating across the disk of the galaxy. Passing through the compression regions, the matter of the disk becomes denser, and the formation of stars from the gas becomes more intense. The reasons for the appearance of such a peculiar wave structure in the disks of spiral galaxies are not entirely clear. Many astrophysicists are working on this problem.

The place of the sun in the galaxy

The distance from the Sun to the center of the Galaxy is 23-28 thousand light years, or 7-9 thousand parsecs. This suggests that the Sun is located closer to the edge of the disk than to its center.

For a long time, the position of the Sun among the stars was considered the most ordinary. Today we know that this is not so: in a certain sense it is privileged. And this must be taken into account when discussing the possibility of the existence of life in other parts of our Galaxy.

The location of the stars

On a cloudless night sky, the Milky Way is visible from anywhere on our planet. However, only a part of the Galaxy, which is a system of stars located inside the Orion arm, is accessible to the human eye. What is the Milky Way? The definition in space of all its parts becomes most understandable if we consider the star map. In this case, it becomes clear that the Sun, illuminating the Earth, is located almost on the disk. This is almost the edge of the Galaxy, where the distance from the nucleus is 26-28 thousand light years. Moving at a speed of 240 kilometers per hour, the Luminary spends 200 million years on one revolution around the core, so that for the entire time of its existence it traveled across the disk, rounding the core, only thirty times. Our planet is in the so-called corotation circle. This is a place in which the speed of rotation of the arms and stars are identical. This circle is characterized by an increased level of radiation. That is why life, as scientists believe, could only arise on that planet, near which there is a small number of stars. Our Earth is such a planet. It is located on the periphery of the Galaxy, in its most peaceful place. That is why on our planet for several billion years there were no global cataclysms that often occur in the Universe.

What will the death of the Milky Way look like?

Triangulum Galaxy. With a mass of about 5% of that of the Milky Way, it is the third largest galaxy in the Local Group. It has a spiral structure, its own satellites and may be a satellite of the Andromeda galaxy.
Large Magellanic Cloud. This galaxy is only 1% of the mass of the Milky Way, but is the fourth largest in our local group. It is very close to our Milky Way - less than 200,000 light-years away - and is undergoing active star formation as tidal interactions with our galaxy cause gas to collapse and give rise to new, hot and large stars in the universe.
Small Magellanic Cloud, NGC 3190 and NGC 6822. All of them have masses from 0.1% to 0.6% of the Milky Way (and it is not clear which one is larger) and all three are independent galaxies. Each contains over a billion solar masses of material.
Elliptical galaxies M32 and M110. They may be "only" satellites of Andromeda, but each of them has more than a billion stars, and they can even exceed the masses of numbers 5, 6 and 7.

So the main thing

Small galaxies that are part of our local group, including both Magellanic Clouds and dwarf elliptical galaxies, will be torn apart in this way, and their material will be incorporated into the large galaxies with which they merge. “So what,” you say. After all, this is not quite death, because large galaxies will remain alive. But even they will not exist forever in this state. In 4 billion years, the mutual gravitational pull of the Milky Way and Andromeda will drag the galaxies into a gravitational dance that will lead to a big merger. Although this process will take billions of years, the spiral structure of both galaxies will be destroyed, resulting in the creation of a single, giant elliptical galaxy at the core of our local group: the Milkweeds.

A small percentage of the stars will be ejected during such a merger, but the majority will remain unharmed, and there will be a large burst of star formation. Eventually, the rest of the galaxies in our local group will also be sucked in, leaving one big giant galaxy to gobble up the rest. This process will take place in all connected groups and clusters of galaxies throughout the Universe, while dark energy will push individual groups and clusters apart from each other. But even this cannot be called death, because the galaxy will remain. And for a while it will be. But the galaxy is made up of stars, dust and gas, and everything will eventually come to an end.

When the last star goes out tens of quadrillion years in the future, there will still be some mass left in the galaxy. So this can not be called "true death."

All masses gravitationally interact with each other, and gravitational objects of different masses exhibit strange properties when interacting:

Repeated "approaches" and close passes cause exchanges of speed and momentum between them.
Objects with low mass are ejected from the galaxy, and objects with higher mass sink into the center, losing speed.
Over a sufficiently long period of time, most of the mass will be ejected, and only a small part of the remaining mass will be firmly attached.

But will it end too?

Mythology

Armenian, Arabic, Wallachian, Jewish, Persian, Turkish, Kyrgyz

Buryat

According to Buryat mythology, good forces create the world, modify the universe. Thus, the Milky Way arose from the milk that Manzan Gurme drew from her breast and splashed out after Abai Geser, who had deceived her. According to another version, the Milky Way is a "seam of the sky" sewn up after the stars fell out of it; on it, like on a bridge, tengri walk.

Hungarian

ancient greek

Indian

Inca

Ketskaya

Chinese, Vietnamese, Korean, Japanese

Indigenous peoples of North America

Maori

Finnish, Lithuanian, Estonian, Erzya, Kazakh

The Finnish name is Fin. Linnunrata- means "The Way of the Birds"; the Lithuanian name has a similar etymology. Estonian myth also connects the Milky ("bird's") Way with bird flight.

The Erzya name is "Kargon Ki" ("Crane Road").

The Kazakh name is “Kus Zholy” (“Way of the Birds”).

Interesting facts about the Milky Way galaxy

The Milky Way began forming as a cluster of dense regions after the Big Bang. The first stars to appear were in globular clusters that continue to exist. These are the oldest stars in the galaxy;
The galaxy has increased its parameters by absorbing and merging with others. Now she is picking stars from the Sagittarius Dwarf Galaxy and the Magellanic Clouds;
The Milky Way moves in space with an acceleration of 550 km / s with respect to the background radiation;
Lurking at the galactic center is the supermassive black hole Sagittarius A*. By mass, it is 4.3 million times greater than the solar one;
Gas, dust and stars revolve around the center at a speed of 220 km/s. This is a stable indicator, implying the presence of a shell of dark matter;
In 5 billion years, a collision with the Andromeda galaxy is expected.

Astronomers say that with the naked eye, a person can see about 4.5 thousand stars. And this, despite the fact that only a small part of one of the most amazing and unidentified pictures of the world opens up to our eyes: only in the Milky Way Galaxy there are more than two hundred billion heavenly bodies (scientists have the opportunity to observe only two billion).

The Milky Way is a barred spiral galaxy, which is a huge star system gravitationally bound in space. Together with neighboring Andromeda and Triangulum galaxies and more than forty dwarf satellite galaxies, it is part of the Virgo Supercluster.

The age of the Milky Way exceeds 13 billion years, and during this time from 200 to 400 billion stars and constellations, more than a thousand huge gas clouds, clusters and nebulae were formed in it. If you look at a map of the Universe, you can see that the Milky Way is represented on it in the form of a disk with a diameter of 30 thousand parsecs (1 parsec is equal to 3.086 * 10 to the 13th degree of kilometers) and an average thickness of about a thousand light years (in one light year, almost 10 trillion kilometers).

How much exactly the Galaxy weighs, astronomers find it difficult to answer, since most of the weight is contained not in the constellations, as previously thought, but in dark matter, which does not emit and does not interact with electromagnetic radiation. According to very rough calculations, the weight of the Galaxy ranges from 5*10 11 to 3*10 12 solar masses.

Like all celestial bodies, the Milky Way turns around its axis and moves in the universe. It should be borne in mind that when moving, galaxies constantly collide with each other in space and the one that is larger absorbs the smaller ones, but if their sizes are the same, active star formation begins after the collision.

So, astronomers put forward the assumption that in 4 billion years the Milky Way in the Universe will collide with the Andromeda Galaxy (they are approaching each other at a speed of 112 km / s), causing the emergence of new constellations in the Universe.

As for the movement around its axis, the Milky Way moves in space unevenly and even chaotically, since each star system, cloud or nebula located in it has its own speed and orbits of different types and shapes.

Structure of the Galaxy

If you look closely at a map of space, you can see that the Milky Way is very compressed in a plane and looks like a "flying saucer" (the solar system is located almost at the very edge of the star system). The Milky Way Galaxy consists of a core, a bar, a disk, spiral arms and a crown.

Core

The core is located in the constellation Sagittarius, where a source of non-thermal radiation is located, the temperature of which is about ten million degrees - a phenomenon that is characteristic only for the nuclei of Galaxies. In the center of the nucleus there is a seal - a bulge, consisting of a large number moving in an elongated orbit of old stars, many of which are at the end of their life cycle.

So, some time ago, American astronomers discovered here an area measuring 12 by 12 parsecs, consisting of dead and dying constellations.

At the very center of the nucleus is a supermassive black hole (a section in outer space that has such powerful gravity that even light is unable to leave it), around which a smaller black hole rotates. Together they have such a strong gravitational influence on nearby stars and constellations that they move along trajectories unusual for celestial bodies in the Universe.

Also, the center of the Milky Way is characterized by an extremely strong concentration of stars, the distance between which is several hundred times less than at the periphery. The speed of movement of most of them is absolutely independent of how far they are from the core, and therefore average speed rotation ranges from 210 to 250 km/s.

Jumper

A 27,000 light-year bridge crosses the central part of the Galaxy at an angle of 44 degrees to the imaginary line between the Sun and the core of the Milky Way. It consists mainly of old red stars (about 22 million), and is surrounded by a gaseous ring, which contains most of the molecular hydrogen, and therefore is the region where stars are formed in the largest number. According to one theory, such active star formation occurs in the bar due to the fact that it passes through itself the gas from which constellations are born.

Disk

The Milky Way is a disk consisting of constellations, gaseous nebulae and dust (its diameter is about 100 thousand light years with a thickness of several thousand). The disk rotates much faster than the corona, which is located at the edges of the Galaxy, while the rotation speed at different distances from the core is not the same and chaotic (ranges from zero in the core to 250 km / h at a distance of 2 thousand light years from it). Near the plane of the disk, gas clouds are concentrated, as well as young stars and constellations.

On the outer side of the Milky Way are layers of atomic hydrogen, which goes into space for one and a half thousand light-years from the extreme spirals. Despite the fact that this hydrogen is ten times thicker than in the center of the Galaxy, its density is just as much lower. On the outskirts of the Milky Way, dense accumulations of gas with a temperature of 10 thousand degrees were discovered, the dimensions of which exceed several thousand light years.

spiral arms

Immediately behind the gas ring there are five main spiral arms of the Galaxy, the size of which ranges from 3 to 4.5 thousand parsecs: Cygnus, Perseus, Orion, Sagittarius and Centaurus (the Sun is located on the inner side of the Orion arm). Molecular gas is located in the arms unevenly and by no means always obeys the rules of rotation of the Galaxy, introducing errors.

Crown

The corona of the Milky Way is represented as a spherical halo that extends beyond the Galaxy into space for five to ten light years. The corona consists of globular clusters, constellations, individual stars (mostly old and low-mass), dwarf galaxies, hot gas. All of them move around the core in elongated orbits, while the rotation of some stars is so random that even the speed of nearby luminaries can differ significantly, so the crown rotates extremely slowly.

According to one hypothesis, the corona arose as a result of the absorption of smaller galaxies by the Milky Way, and therefore is their remnants. According to preliminary data, the age of the halo exceeds twelve billion years and it is the same age as the Milky Way, and therefore star formation has already been completed here.

starry space

If you look at the night starry sky, the Milky Way can be seen from absolutely anywhere on the globe in the form of a lightish stripe (since our star system is located inside the Orion arm, only part of the Galaxy is available for viewing).

The map of the Milky Way shows that our Luminary is located almost on the disk of the Galaxy, at its very edge, and its distance to the core is from 26-28 thousand light years. Given that the Sun moves at a speed of about 240 km / h, in order to make one revolution, it needs to spend about 200 million years (for the entire period of its existence, our star has not circled the Galaxy even thirty times).

It is interesting that our planet is located in a corotation circle - a place where the speed of rotation of stars coincides with the speed of rotation of the arms, so the stars never leave these arms or enter them. This circle is characterized high level radiation, therefore it is believed that life can arise only on planets near which there are very few stars.

It is this fact that applies to our Earth. Being on the periphery, it is located in a rather calm place in the Galaxy, and therefore for several billion years it has hardly been subjected to global cataclysms, which the Universe is so rich in. Perhaps this is one of the main reasons that life was able to originate and survive on our planet.