Earth is in the Milky Way galaxy. Interesting facts about the milky way galaxy

The Milky Way Galaxy contains the solar system, the Earth and all the stars that are visible to the naked eye. Together with the Triangulum, Andromeda and dwarf galaxies and satellites, it forms the Local Group of galaxies, which is part of the Virgo Supercluster.

According to an ancient legend, when Zeus decided to make his son Hercules immortal, he placed him on the breast of his wife Hera to drink milk. But the wife woke up and, seeing that she was feeding a step-child, pushed him away. A stream of milk splashed and turned into the Milky Way. In the Soviet astronomical school, it was simply called "the Milky Way system" or "our Galaxy." Outside of Western culture, there are many names for this galaxy. The word "milky" is replaced by other epithets. The galaxy consists of about 200 billion stars. Most of them are located in the form of a disk. Most of the mass of the Milky Way is contained in a halo of dark matter.

In the 1980s, scientists put forward the view that the Milky Way is a barred spiral galaxy. The hypothesis was confirmed in 2005 using the Spitzer telescope. It turned out that the central bar of the galaxy is larger than previously thought. The diameter of the galactic disk is approximately 100 thousand light years. Compared to the halo, it spins much faster. At different distances from the center, its speed is not the same. Studies of the disk's rotation helped to estimate its mass, which is 150 billion more than the mass of the Sun. Near the plane of the disk, young star clusters and stars are collected, which form a flat component. Scientists suggest that many galaxies have black holes in their core.

A large number of stars are collected in the central regions of the Milky Way Galaxy. The distance between them is much smaller than in the vicinity of the Sun. The length of the galactic bridge, according to scientists, is 27 thousand light years. It passes through the center of the Milky Way at an angle of 44 degrees ± 10 degrees to the line between the center of the galaxy and the Sun. Its component is predominantly red stars. The jumper is surrounded by a ring, which is called the "Ring of 5 kiloparsecs". It contains a large amount of molecular hydrogen. It is also an active star-forming region in the galaxy. Viewed from the Andromeda galaxy, the bar of the Milky Way would be its brightest part.

Since the Milky Way Galaxy is considered a spiral galaxy, it has spiral arms that lie in the plane of the disk. Around the disk is a spherical corona. The solar system is located 8.5 thousand parsecs from the center of the galaxy. According to recent observations, we can say that our Galaxy has 2 arms and a couple more arms in the inner part. They transform into a four-arm structure, which is observed in the neutral hydrogen line.

The halo of the galaxy has a spherical shape, which extends beyond the Milky Way by 5–10 thousand light years. Its temperature is approximately 5 * 10 5 K. The halo consists of old, low-mass, dim stars. They can be found in the form of globular clusters, and one by one. The main mass of the galaxy is dark matter, which forms a halo of dark matter. Its mass is approximately 600–3000 billion solar masses. Star clusters and halo stars move around the galactic center in elongated orbits. The halo rotates very slowly.

History of the discovery of the Milky Way Galaxy

Many celestial bodies are combined into a variety of rotating systems. Thus, the Moon revolves around the Earth, and the satellites of the major planets form their systems. The earth and other planets revolve around the sun. Scientists had a completely logical question: is the Sun included in an even larger system?

For the first time, William Herschel tried to answer this question. He calculated the number of stars in different parts of the sky and found out that there is a large circle in the sky - the galactic equator, dividing the sky into two parts. Here the number of stars was the greatest. The closer this or that part of the sky is located to this circle, the more stars there are on it. Ultimately, it was discovered that the Milky Way is located at the equator of the galaxy. Herschel came to the conclusion that all the stars form one star system.

Initially it was believed that everything in the universe is part of our galaxy. But even Kant argued that some nebulae can be separate galaxies, like the Milky Way. Only when Edwin Hubble measured the distance to some spiral nebulae and showed that they could not be part of the Galaxy, Kant's hypothesis was proven.

Future of the Galaxy

In the future, collisions of our Galaxy with others, including Andromeda, are possible. But there are no concrete predictions yet. It is believed that in 4 billion years the Milky Way will be swallowed up by the Small and Large Magellanic Clouds, and in 5 billion years it will be swallowed up by the Andromeda Nebula.

Planets of the Milky Way

Despite the fact that stars are constantly born and die, their number is clearly counted. Scientists believe that at least one planet revolves around every star. This means that there are from 100 to 200 billion planets in the Universe. The scientists who worked on this statement studied "red dwarf" stars. They are smaller than the Sun and make up 75% of all stars in the Milky Way Galaxy. Particular attention was paid to the star Kepler-32, which "sheltered" 5 planets.

Planets are much harder to spot than stars because they don't emit light. We can confidently say about the existence of a planet only when it obscures the light of a star.

There are also planets that are similar to our Earth, but there are not so many of them. There are many types of planets, for example, pulsar planets, gas giants, brown dwarfs... If a planet is composed of rocks, it will bear little resemblance to Earth.

Recent studies claim that there are between 11 and 40 billion Earth-like planets in the galaxy. Scientists examined 42 sun-like stars and found 603 exoplanets, 10 of which matched the search criteria. It has been proven that all planets similar to Earth can maintain the right temperature for the existence of liquid water, which, in turn, will help the emergence of life.

At the outer edge of the Milky Way, stars have been discovered that move in a special way. They drift off the edge. Scientists suggest that this is all that is left of the galaxies that were swallowed up by the Milky Way. Their encounter happened many years ago.

satellite galaxies

As we have said, the Milky Way Galaxy is a spiral galaxy. It is an irregularly shaped spiral. For many years, scientists could not find an explanation for the bulge of the galaxy. Now everyone has come to the conclusion that this is due to satellite galaxies and dark matter. They are very small and cannot affect the Milky Way. But as dark matter moves through the Magellanic Clouds, waves are created. They also influence gravitational attraction. Under this action, hydrogen escapes from the galactic center. Clouds revolve around the Milky Way.

Although the Milky Way is called unique in many ways, it is not a rarity. If we take into account the fact that there are approximately 170 billion galaxies in the field of view, we can assert the existence of galaxies similar to ours. In 2012, astronomers found an exact copy of the Milky Way. It even has two satellites that correspond to the Magellanic Clouds. By the way, they assume that in a couple of billion years they will dissolve. Finding such a galaxy was an incredible stroke of luck. Named NGC 1073, it looks so much like the Milky Way that astronomers study it to learn more about our galaxy.

Galactic year

An Earth year is the time it takes a planet to complete one revolution around the sun. In the same way, the solar system revolves around the black hole, which is located in the center of the galaxy. Its full rotation is 250 million years. When describing the solar system, they rarely mention that it moves in outer space, like everything else in the world. The speed of its movement is 792,000 km per hour relative to the center of the Milky Way Galaxy. If we compare, then we, moving at a similar speed, could go around the whole world in 3 minutes. A galactic year is the time it takes for the sun to complete one revolution around the Milky Way. At last count, the sun lived for 18 galactic years.

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 provides the influx of 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
In appearance, the galaxy resembles a disk (since 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, a bulge diameter of 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 and 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 cosmos that we are trying to study is a vast and boundless space in which there are tens, hundreds, thousands of trillions of stars united in certain groups. Our Earth does not live on its own. We are part of the solar system, which is a small particle and part of the Milky Way - a larger cosmic entity.

Our Earth, like other planets of the Milky Way, our star named the Sun, like other stars of the Milky Way, move in the Universe in a certain order and occupy the allotted places. Let's try to understand in more detail what is the structure of the Milky Way, and what are the main features of our galaxy?

Origin of the Milky Way

Our galaxy has its own history, like other areas of outer space, and is the product of a catastrophe on a universal scale. The main theory of the origin of the Universe that dominates the scientific community today is the Big Bang. The model that perfectly characterizes the Big Bang theory is the nuclear chain reaction at the microscopic level. Initially, there was some kind of substance, which, due to certain reasons, in an instant set in motion and exploded. It is not worth talking about the conditions that led to the onset of the explosive reaction. This is far from our understanding. Now formed 15 billion years ago as a result of a cataclysm, the Universe is a huge, endless polygon.

The primary products of the explosion were at first accumulations and clouds of gas. Later, under the influence of gravitational forces and other physical processes, the formation of larger objects of a universal scale took place. Everything happened very quickly by cosmic standards, over billions of years. First there was the formation of stars, which formed clusters and later coalesced into galaxies, the exact number of which is unknown. In its composition, galactic matter is hydrogen and helium atoms in the company of other elements, which are the building material for the formation of stars and other space objects.

It is not possible to say exactly where in the Universe the Milky Way is located, since the center of the universe is not exactly known.

Due to the similarity of the processes that formed the Universe, our galaxy is very similar in its structure to many others. By its type, this is a typical spiral galaxy, a type of objects that is common in the Universe in a huge variety. In terms of size, the galaxy is in the golden mean - not small and not huge. Our galaxy has many more smaller neighbors in a stellar home than those who are colossal in size.

The age of all galaxies that exist in outer space is the same. Our galaxy is almost the same age as the Universe and has an age of 14.5 billion years. During this vast period of time, the structure of the Milky Way has repeatedly changed, and this is happening today, only imperceptibly, in comparison with the pace of earthly life.

The history with the name of our galaxy is curious. Scientists believe that the name Milky Way is legendary. This is an attempt to connect the location of the stars in our sky with the ancient Greek myth about the father of the gods Kronos, who devoured his own children. The last child, who faced the same sad fate, turned out to be thin and was given to the nurse for fattening. During feeding, splashes of milk fell into the sky, thereby creating a milk path. Subsequently, scientists and astronomers of all times and peoples agreed that our galaxy is really very similar to a milky road.

The Milky Way is currently in the middle of its development cycle. In other words, cosmic gas and matter for the formation of new stars are coming to an end. The existing stars are still quite young. As in the story with the Sun, which may turn into a Red Giant in 6-7 billion years, our descendants will observe the transformation of other stars and the entire galaxy as a whole into the red sequence.

Our galaxy may also cease to exist as a result of another universal cataclysm. Topics of research in recent years are focused on the forthcoming meeting of the Milky Way with our nearest neighbor, the Andromeda galaxy. It is likely that the Milky Way, after meeting with the Andromeda galaxy, will break up into several small galaxies. In any case, this will be the reason for the emergence of new stars and the reconstruction of the space closest to us. It remains only to guess what is the fate of the Universe and our galaxy in the distant future.

Astrophysical parameters of the Milky Way

In order to imagine what the Milky Way looks like on the scale of space, it is enough to look at the Universe itself and compare its individual parts. Our galaxy is part of a subgroup, which in turn is part of the Local Group, a larger entity. Here our space metropolis is adjacent to the Andromeda and Triangulum galaxies. Surrounding the trinity are more than 40 small galaxies. The local group is already part of an even larger formation and is part of the Virgo supercluster. Some argue that these are only rough guesses about where our galaxy is. The scale of formations is so huge that it is almost impossible to imagine all this. Today we know the distance to the nearest neighboring galaxies. Other deep sky objects are out of sight. Only theoretically and mathematically their existence is allowed.

The location of the galaxy became known only thanks to approximate calculations that determined the distance to the nearest neighbors. The satellites of the Milky Way are dwarf galaxies - the Small and Large Magellanic Clouds. In total, according to scientists, there are up to 14 satellite galaxies that make up the escort of the universal chariot called the Milky Way.

As for the observable world, today there is enough information about what our galaxy looks like. The existing model, and with it the map of the Milky Way, was compiled on the basis of mathematical calculations obtained from astrophysical observations. Each cosmic body or fragment of the galaxy takes its place. It's like the universe, only on a smaller scale. The astrophysical parameters of our space metropolis are interesting, and they are impressive.

Our galaxy is a spiral-type galaxy with a bar, which on star maps is denoted by the index SBbc. The diameter of the galactic disk of the Milky Way is about 50-90 thousand light years or 30 thousand parsecs. For comparison, the radius of the Andromeda galaxy is 110 thousand light years on the scale of the Universe. One can only imagine how much larger the Milky Way is our neighbor. The dimensions of the dwarf galaxies closest to the Milky Way are ten times smaller than the parameters of our galaxy. Magellanic clouds have a diameter of only 7-10 thousand light years. In this huge stellar cycle, there are about 200-400 billion stars. These stars are collected in clusters and nebulae. A significant part of it is the arms of the Milky Way, in one of which our solar system is located.

Everything else is dark matter, clouds of cosmic gas and bubbles that fill interstellar space. The closer to the center of the galaxy, the more stars, the tighter space becomes. Our Sun is located in a region of space, consisting of smaller space objects located at a considerable distance from each other.

The mass of the Milky Way is 6x1042 kg, which is trillions of times the mass of our Sun. Almost all the stars that inhabit our stellar country are located in the plane of one disk, the thickness of which, according to various estimates, is 1000 light years. It is not possible to know the exact mass of our galaxy, since most of the visible spectrum of stars is hidden from us by the arms of the Milky Way. In addition, the mass of dark matter that occupies vast interstellar spaces is unknown.

The distance from the Sun to the center of our galaxy is 27 thousand light years. Being on the relative periphery, the Sun is rapidly moving around the center of the galaxy, making a complete revolution in 240 million years.

The center of the galaxy is 1000 parsecs in diameter and consists of a core with an interesting sequence. The center of the core has the shape of a bulge, in which the largest stars and a cluster of hot gases are concentrated. It is this region that releases a huge amount of energy, which in aggregate is more than the billions of stars that make up the galaxy radiate. This part of the core is the most active and brightest part of the galaxy. Along the edges of the core there is a jumper, which is the beginning of the arms of our galaxy. Such a bridge arises as a result of the colossal force of gravity caused by the rapid rotation of the galaxy itself.

Considering the central part of the galaxy, the following fact looks paradoxical. Scientists for a long time could not understand what is at the center of the Milky Way. It turns out that in the very center of a starry country called the Milky Way, a supermassive black hole has settled down, the diameter of which is about 140 km. It is there that most of the energy released by the core of the galaxy goes, it is in this bottomless abyss that the stars dissolve and die. The presence of a black hole at the center of the Milky Way indicates that all processes of formation in the Universe must someday end. Matter will turn into antimatter and everything will repeat again. How this monster will behave in millions and billions of years, the black abyss is silent, which indicates that the processes of absorption of matter are only gaining momentum.

Two main arms of the galaxy extend from the center - the Shield of the Centaur and Perseus. These structural formations were named after the constellations located in the sky. In addition to the main arms, the galaxy is surrounded by 5 more small arms.

Near and distant future

The arms, born from the core of the Milky Way, spiral outward, filling outer space with stars and cosmic material. An analogy with cosmic bodies that revolve around the Sun in our star system is appropriate here. A huge mass of stars, large and small, clusters and nebulae, cosmic objects of various sizes and nature, spins on a giant carousel. All of them create a wonderful picture of the starry sky, which a person has been looking at for more than one thousand years. When studying our galaxy, you should know that the stars in the galaxy live according to their own laws, being in one of the arms of the galaxy today, tomorrow they will start their journey in the other direction, leaving one arm and flying into another.

Earth in the Milky Way galaxy is far from the only planet suitable for life. This is just a particle of dust, the size of an atom, which was lost in the vast stellar world of our galaxy. There can be a huge number of such planets similar to Earth in the galaxy. It is enough to imagine the number of stars that somehow have their own stellar planetary systems. Other life may be far away, at the very edge of the galaxy, tens of thousands of light years away, or, conversely, be present in neighboring regions that are hidden from us by the arms of the Milky Way.

The Milky Way is our home galaxy, a family of 100 billion stars. Their light forms a pale path in the night sky; its various parts are visible anywhere on Earth. Our Galaxy has spiral arms, stars, gas and dust. It is possible that there is a giant black hole at its center. The disk of the Galaxy is surrounded by a vast cloud - a halo - of invisible matter.

What exactly is the Milky Way? There are 100 billion stars arranged in a thin disk with spiral arms. Since we live inside the Galaxy, its shape is difficult to imagine directly. When observing the Milky Way from the starboard, we are looking in a direction that lies in the plane of the disk.

How to see the Milky Way is hindered by eider clouds and whining. They are transparent to radio waves, and radio astronomers have established that the Galaxy is a large spiral, and the Sun is also located at a distance of 25,000 light years from the center. The diameter of the main part of the disk, consisting of stars, reaches 100,000 snow years, but its thickness is much less. In the part where the Sun is located, it does not exceed several hundred snow years.

In the center of the inner part of the disk there is a thickening, a sphere of stars about 3000 light-years thick. In this region, the stars are packed much more densely than in the disk. The spiral disk, along with its central thickening, is located inside a vast halo - a cloud of matter that extends 150,000 light-years from the center.

Inside the disk

The disk of the Galaxy resembles a thin pancake. It has four spiral branches - arms containing gas, dust and young stars. Our Sun is in the Orion Arm, which is the branch that includes the Orion Nebula and the North America Nebula. Between the Sun and the central thickening is the arm of Sagittarius - Carina, about 75,000 light-years long.

The galaxy is spinning. The inner parts pass through their orbits much faster than the outer ones. The same pattern is observed in the solar system, where Mercury goes around the Sun in 88 days, and Pluto in 243 years. The galactic journey of our Sun takes about 200 million years. The age of the Sun is about 25 galactic years, since it managed to go around the Galaxy 25 times.

Since the regions closer to the center of the Galaxy rotate in their orbits faster, the question arises why the spiral arms did not wrap hundreds of times over each other in this cosmic whirlpool. The answer is: the spiral branches are "density waves," traffic jams on the cosmic highway, where congestion always forms in the same places, although every "car" (every star in the Milky Way) eventually passes on.

When stars and gas, in their orbital motion around the Galaxy, approach the spiral arm, they crash into the slowly moving material of the arm. New stars can be born in such interaction zones. As the gas and dust clump into a dense formation, the compressed clouds collapse under the force of gravity and create new stars. When observing other spiral galaxies, young stars and bright radiating nebulae can be seen in their spiral arms. In these arms are open clusters, entire families of the youngest stars.

Runaway Stars

Most stars in the vicinity of the Sun move in galactic orbits at speeds of 30 to 50 km per second, but there are some stars that travel more than twice as fast. The orbits of these fast stars cross the disk of the Galaxy through and through. Outside, in the galactic halo, the stars have very high speeds.

invisible galaxy

Knowing the orbital velocities of stars and gas, astronomers calculate the amount of matter inside the galaxy. The faster a star moves in an orbit with a given radius, the more massive its galaxy must be. In exactly the same way, the mass of the Sun is found, using the relationship between the orbital velocity of the planet, the radius of its orbit, and the mass of the Sun.

The speed of the Sun and its distance from the center of the Galaxy indicate that the mass of the Galaxy contained within the orbit of the Sun is about 100 billion solar masses. This roughly coincides with the mass of visible stars and gas.

However, the stars outside the solar orbit tell us something very different. Instead of slowing down as you move away from the center (as happens with the planets and the solar system), the speeds of stars remain more or less constant. This can only happen when the stars are attracted by the much stronger gravitational forces created by the gigantic amount of invisible matter. Clusters in the galactic halo move as if they were attracted by 10 times more matter than what we see.

The Milky Way has a companion galaxy at the bottom, the Large and Small Magellanic Clouds. The orbit of one of them indicates that the mass contained in the halo is 5 to 10 times the mass that we observe in the disk.

Invisible substance in the halo

Most of the matter in the galactic halo is invisible and therefore cannot be contained in ordinary stars. It is not a gas either, as it would be detected by radio telescopes or ultraviolet telescopes. Light from distant galaxies passes through the halo to us, so the extra mass cannot be dust. Dark matter hidden from us could consist of some mysterious atomic or nuclear particles, not yet discovered on Earth. On the other hand, countless cold "planets" or black holes can form the hidden mass. Anyway, now nine-tenths of the Milky Way galaxy is invisible. In the future, we will see that this problem of hidden mass extends to other galaxies, and even to the entire Universe.

Centre

The center of the Milky Way galaxy lies in the direction of the constellation Sagittarius. The center cannot be seen in optical telescopes, as it is obscured by vast accumulations of nyls. However, they are permeable to radio waves and infrared radiation, which provide us with information about the center of the Galaxy.

Within 1000 light-years from the center, the stars are very densely packed. If you were on any planet inside this crowded zone, you would see a good million very bright stars in the night sky, so that darkness would never come. The nearest stars would be only a few light days away.

Something big is happening in the heart of the Milky Way. The central region is a powerful source of radio waves, infrared and X-rays. Powerful infrared radiation comes from a region only 20 light years across. The radio maps of this area show clouds of gas rushing towards the center. A ragged ring of gas swirls around the center; hot gas, escaping from its inner edge, falls to the center.

central monster

At the very heart of the Milky Way is a mysterious source of colossal energy. Shining like a hundred million suns, it is so small in size that it could fit entirely inside the orbit of Jupiter. Its mass is about a million times that of the sun. Almost certainly there is a black hole there, greedily devouring interstellar gas and dust and drawing in fresh food from the ragged gas ring. Falling into a black hole, this gas heats up and releases energy, which we observe.

Not all astronomers agree with the hypothesis that energy is generated by a black hole. In their opinion, the release of such energy could be the result of a powerful explosion of stellar births.

Our Neighbors, Magellanic Clouds

Two galaxies that are satellites of the Milky Way, the Large and Small Magellanic Clouds, were discovered in the 16th century. Portuguese navigators while sailing to the shores of South Africa. Subsequently, they were named after Ferdinand Magellan (1480-1521), the leader of the first trip around the world (1519-1522). Magellanic clouds are visible in the southern hemisphere. The Large Cloud is 165,000 light years from us, while the Small Cloud is 200,000 light years away.

The Large Cloud has a central band of stars, but no spiral structure. It is a medium-sized galaxy—it contains about 20 billion stars. It is 10 times closer to us than the nearest large galaxy. Since individual stars can be seen in the Large Cloud, astronomers often observe this galaxy, trying to study the life path of ordinary stars. In the Big Cloud is a giant radiant nebula - Tarantula. It is a gigantic cloud of supergiant stars and gas. There is a large "factory of stars" here. In 1987, it was in this region that the famous supernova explosion occurred.

Galactic cannibalism

Both Magellanic Clouds move in orbits around our Galaxy. Since they are so far away from us, their movement across the sky is almost imperceptible. However, in 1993, astronomers still managed to measure this movement by comparing photographs taken with an interval of 17 years. The stars of the Great Cloud moved just enough in that time to detect this movement. Knowing its speed, astronomers calculated the Big Cloud's orbit. In doing so, they ran into two big surprises.

First of all, the speed was greater than expected. This could only be explained by assuming that the Milky Way is even larger than previously thought. Apparently, the invisible massive halo is about 10 times larger than the spiral disk of the Galaxy. Traveling in orbit around the Milky Way takes the Great Cloud about 2.5 billion years.

Secondly, the orbit passes very close to the massive halo. As a result, every time the Big Cloud gets close enough, gravitational forces tear it to shreds. A giant tail of debris, consisting of star clusters and hydrogen, is sucked out. As a result, a long thin arc of matter separated from the Great Cloud, which is currently falling onto the Milky Way. The same fate is with the Small Cloud. Satellite galaxies, like giant galactic-scale comets, leave debris tails behind them. According to astronomers, in the next 10 billion years, the Milky Way will commit an act of galactic cannibalism, completely absorbing all the matter of the Magellanic Clouds.

Path to the Universe

All the stars in the Large Magellanic Cloud are more or less the same distance from us. It's about the same as saying, "All New Yorkers are the same distance from London." This means that the differences in the magnitudes of individual stars in the Magellanic Cloud are entirely due to differences in their age and chemical composition. When observing the stars of our own Galaxy, we must take into account that the distances to them are completely different, and the exact determination of these distances is a difficult task. Comparing the stars of the Magellanic Clouds with each other, one can be sure that the difference in distances has almost no effect on the result.

The Milky Way Galaxy is very majestic, beautiful. This huge world is our homeland, our solar system. All the stars and other objects that are visible to the naked eye in the night sky are our galaxy. Although there are some objects that are located in the Andromeda Nebula - a neighbor of our Milky Way.

Description of the Milky Way

The Milky Way galaxy is huge, 100 thousand light years in size, and, as you know, one light year is equal to 9460730472580 km. Our solar system is located at a distance of 27,000 light years from the center of the galaxy, in one of the arms, which is called the Orion arm.

Our solar system revolves around the center of the Milky Way galaxy. This happens in the same way that the Earth revolves around the Sun. The solar system makes a complete revolution in 200 million years.

Deformation

The Milky Way galaxy looks like a disk with a bulge in the center. It's not in perfect shape. On one side there is a bend to the north of the center of the galaxy, and on the other it goes down, then turns to the right. Outwardly, such a deformation is somewhat reminiscent of a wave. The disk itself is warped. This is due to the presence of the Small and Large Magellanic Clouds nearby. They orbit the Milky Way very quickly - this was confirmed by the Hubble telescope. These two dwarf galaxies are often referred to as satellites of the Milky Way. The clouds create a gravitationally bound system that is very heavy and quite massive due to the heavy elements in the mass. It is assumed that they are like a tug of war between galaxies, creating vibrations. The result is a deformation of the Milky Way galaxy. The structure of our galaxy is special, it has a halo.

Scientists believe that in billions of years the Milky Way will be swallowed up by the Magellanic Clouds, and after some more time it will be swallowed up by Andromeda.

Halo

Wondering what kind of galaxy the Milky Way is, scientists began to study it. They managed to find out that for 90% of its mass it consists of dark matter, which causes a mysterious halo. Everything that is visible to the naked eye from the Earth, namely that luminous matter, is about 10% of the galaxy.

Numerous studies have confirmed that the Milky Way has a halo. Scientists have compiled various models that take into account the invisible part and without it. After the experiments, the opinion was put forward that if there were no halo, then the speed of the planets and other elements of the Milky Way would be less than now. Because of this feature, it was suggested that most of the components consist of an invisible mass or dark matter.

Number of stars

One of the most unique is the Milky Way galaxy. The structure of our galaxy is unusual, it has more than 400 billion stars. About a quarter of them are large stars. Note: other galaxies have fewer stars. There are about ten billion stars in the Cloud, some others consist of a billion, and in the Milky Way there are more than 400 billion very different stars, and only a small part, about 3000, is visible from the Earth. It is impossible to say exactly how many stars are in the Milky Way, because how the galaxy is constantly losing objects due to their transformation into supernovae.

Gases and dust

Approximately 15% of the galaxy is dust and gases. Maybe because of them our galaxy is called the Milky Way? Despite its huge size, we can see about 6,000 light-years ahead, but the size of the galaxy is 120,000 light-years. Maybe it is more, but even the most powerful telescopes cannot see beyond this. This is due to the accumulation of gas and dust.

The thickness of the dust does not allow visible light to pass through, but infrared light passes through it, and scientists can create maps of the starry sky.

What was before

According to scientists, our galaxy has not always been like this. The Milky Way was created from the merger of several other galaxies. This giant captured other planets, areas, which had a strong influence on the size and shape. Even now, planets are being captured by the Milky Way galaxy. An example of this is the objects of Canis Major, a dwarf galaxy located near our Milky Way. Canis stars are periodically added to our universe, and from ours they pass to other galaxies, for example, there is an exchange of objects with the Sagittarius galaxy.

view of the milky way

No scientist, astronomer can say for sure what our Milky Way looks like from above. This is due to the fact that the Earth is located in the Milky Way galaxy, 26,000 light-years from the center. Due to this location, it is not possible to take pictures of the entire Milky Way. Therefore, any image of a galaxy is either a snapshot of other visible galaxies, or someone else's fantasy. And we can only guess what it actually looks like. There is even a possibility that we now know as much about it as the ancient people who considered the Earth to be flat.

Centre

The center of the Milky Way galaxy is called Sagittarius A * - a great source of radio waves, suggesting that there is a huge black hole at the very heart. According to assumptions, its dimensions are a little more than 22 million kilometers, and this is the hole itself.

All the matter that tries to get into the hole forms a huge disk, almost 5 million times the size of our Sun. But even such a pulling force does not prevent new stars from forming at the edge of a black hole.

Age

According to estimates of the composition of the Milky Way galaxy, it was possible to establish an estimated age of about 14 billion years. The oldest star is just over 13 billion years old. The age of a galaxy is calculated by determining the age of the oldest star and the phases preceding its formation. Based on the available data, scientists have suggested that our universe is about 13.6-13.8 billion years old.

First, the bulge of the Milky Way was formed, then its middle part, in the place of which a black hole subsequently formed. Three billion years later, a disk with sleeves appeared. Gradually, it changed, and only about ten billion years ago did it begin to look like it does now.

We are part of something bigger

All the stars in the Milky Way galaxy are part of a larger galactic structure. We are part of the Virgo Supercluster. The nearest galaxies to the Milky Way, such as the Magellanic Cloud, Andromeda and other fifty galaxies, are one cluster, the Virgo Supercluster. A supercluster is a group of galaxies that covers a huge area. And this is only a small part of the stellar neighborhood.

The Virgo Supercluster contains more than a hundred groups of clusters over 110 million light-years across. The Virgo cluster itself is a small part of the Laniakea supercluster, and it, in turn, is part of the Pisces-Cetus complex.

Rotation

Our Earth moves around the Sun, making a complete revolution in 1 year. Our Sun revolves in the Milky Way around the center of the galaxy. Our galaxy is moving in relation to a special radiation. CMB radiation is a convenient reference point that allows you to determine the speed of various matters in the Universe. Studies have shown that our galaxy rotates at a speed of 600 kilometers per second.

Name appearance

The galaxy got its name because of its special appearance, reminiscent of spilled milk in the night sky. The name was given to her in ancient Rome. Then it was called "the road of milk." Until now, it is called that - the Milky Way, associating the name with the appearance of a white stripe in the night sky, with spilled milk.

Mentions have been found about the galaxy since the era of Aristotle, who said that the Milky Way is a place where the celestial spheres are in contact with the earthly ones. Until the moment when the telescope was created, no one added anything to this opinion. And only since the seventeenth century people began to look at the world differently.

Our neighbours

For some reason, many people think that the closest galaxy to the Milky Way is Andromeda. But this opinion is not entirely correct. The closest "neighbor" to us is the Canis Major galaxy, located inside the Milky Way. It is located at a distance of 25,000 light years from us, and 42,000 light years from the center. In fact, we are closer to Canis Major than to the black hole at the center of the galaxy.

Before the discovery of Canis Major at a distance of 70 thousand light years, Sagittarius was considered the closest neighbor, and after that - the Large Magellanic Cloud. Unusual stars with a huge density of class M were discovered in Pse.

According to the theory, the Milky Way swallowed Canis Major along with all of its stars, planets and other objects.

Collision of galaxies

Recently, there is more and more information that the nearest galaxy to the Milky Way, the Andromeda Nebula, will swallow our universe. These two giants formed at about the same time - about 13.6 billion years ago. It is believed that these giants are able to unite galaxies, and due to the expansion of the Universe, they must move away from each other. But, contrary to all the rules, these objects move towards each other. The speed of movement is 200 kilometers per second. It is estimated that in 2-3 billion years Andromeda will collide with the Milky Way.

Astronomer J. Dubinsky created the collision model shown in this video:

The collision will not lead to a global catastrophe. And after several billion years, a new system will form, with the usual galactic forms.

Dead galaxies

Scientists conducted a large-scale study of the starry sky, covering about an eighth of it. As a result of the analysis of the star systems of the Milky Way galaxy, it was possible to find out that there are previously unknown streams of stars on the outskirts of our universe. This is all that remains of small galaxies that were once destroyed by gravity.

A telescope installed in Chile took a huge number of images that allowed scientists to assess the sky. Surrounding our galaxy, according to the images, are halos of dark matter, rarefied gas and few stars, remnants of dwarf galaxies that were once swallowed up by the Milky Way. With enough data, scientists managed to collect the "skeleton" of the dead galaxies. It's like in paleontology - it's hard to tell from a few bones what the creature looked like, but with enough data, you can assemble the skeleton and guess what the lizard was like. So it is here: the information content of the images made it possible to recreate eleven galaxies that were swallowed up by the Milky Way.

Scientists are confident that as they observe and evaluate the information they receive, they will be able to find several more new decayed galaxies that were “eaten” by the Milky Way.

We're under fire

According to scientists, the hypervelocity stars in our galaxy did not originate in it, but in the Large Magellanic Cloud. Theorists cannot explain many points regarding the existence of such stars. For example, it is impossible to say exactly why a large number of hypervelocity stars are concentrated in Sextant and Leo. Revising the theory, scientists came to the conclusion that such a speed can only develop due to the impact on them of a black hole located in the center of the Milky Way.

Recently, more and more stars are being discovered that do not move from the center of our galaxy. After analyzing the trajectory of ultrafast stars, scientists managed to find out that we are under attack from the Large Magellanic Cloud.

The death of the planet

By observing the planets in our galaxy, scientists were able to see how the planet died. She was consumed by an aging star. During the expansion and transformation into a red giant, the star swallowed up its planet. And another planet in the same system changed its orbit. Seeing this and assessing the state of our Sun, scientists came to the conclusion that the same thing will happen to our luminary. In about five million years, it will turn into a red giant.

How the galaxy works

Our Milky Way has several arms that rotate in a spiral. The center of the entire disk is a gigantic black hole.

We can see galactic arms in the night sky. They look like white stripes, reminiscent of a milky road that is strewn with stars. These are the branches of the Milky Way. They are best seen in clear weather during the warm season, when there is the most cosmic dust and gases.

Our galaxy has the following arms:

Angle branch.
Orion. Our solar system is located in this arm. This sleeve is our "room" in the "house".
Sleeve Keel-Sagittarius.
Branch of Perseus.
Branch of the Shield of the Southern Cross.

Also in the composition there is a core, a gas ring, dark matter. It supplies about 90% of the entire galaxy, and the remaining ten are visible objects.

Our solar system, the Earth and other planets are a single whole of a huge gravitational system that can be seen every night in a clear sky. A variety of processes are constantly taking place in our “house”: stars are born, decay, other galaxies are shelling us, dust, gases appear, stars change and go out, others flare up, they dance around ... And all this happens somewhere far away in a universe about which we know so little. Who knows, maybe the time will come when people will be able to reach other arms and planets of our galaxy in a matter of minutes, travel to other universes.