Our ancestors are aliens from other galaxies. Strange radio pulses from another galaxy: maybe they are aliens after all? Spiral galaxies with the Messier catalog bar
Search for extraterrestrial life in the Universe
Now everyone knows that in the solar system the only carrier of intelligence is our Earth. Therefore, “brothers in mind” should be sought on planets orbiting distant stars-suns. The number of inhabited worlds depends on a number of astronomical, biological, climatic and other factors. And only as a result of a favorable combination of these circumstances, that is, the conditions necessary for life, can we expect that a highly developed civilization will arise on the planet.
For the emergence and further life of protein organisms on the planet, suitable temperature conditions are required, first of all. To do this, the planet must fall exactly into the “habitable zone.” Our Earth can serve as a clear example of such a successful location of the orbit around the central luminary. Its space neighbors Venus and Mars are already outside this zone. Venus is too close to the Sun, Mars is beyond the permissible limit. In addition, a habitable planet must have an orbit close to circular so that sudden temperature changes do not occur on its surface. And the radiation from a star should remain approximately constant over hundreds of millions or even billions of years. Therefore, we can meet highly developed living beings only on planets orbiting fairly old stars (like the Sun) of late spectral classes - F, G and K.
A very important condition for maintaining highly developed life on the planet is the mass of the celestial body. If the mass of the planet
Ring galaxy AM 0644-741 as seen through the Hubble telescope. The edge of the blue galaxy, just to the right of center in this image, is a huge ring-shaped structure 150,000 light-years in diameter, made up of young stars. |
Billions of different galaxies in the Universe |
Leo A: Nearby dwarf irregular galaxy. Today, Leo A is known as a dwarf irregular galaxy, one of the most numerous types of galaxies in the Universe that may be the building blocks of more massive galaxies. |
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The most ancient organisms known on Earth, blue-green algae, appeared when our planet was hundreds of millions of years old. In the Cambrian period, about 500 million years ago, plants began to emerge on land. At that time, the earth's atmosphere was oversaturated with carbon dioxide released from fire-breathing volcanic vents. The abundance of carbon dioxide contributed to the rapid growth of plants. Thanks to plant photosynthesis, the earth's atmosphere was almost completely “cleared” of carbon dioxide and gained oxygen. Thus, in the process of development of the plant kingdom, the Earth’s atmosphere underwent a radical restructuring: from oxygen-free it turned into oxygen.
Many scientists believe that life on our planet originally arose and developed in water. And, apparently, at a sufficient depth. After all, the Earth at that time was not protected from destructive cosmic radiation, so the role of an ozone shield for the first primitive organisms was played by a layer of water up to several tens of meters thick. After about 4 billion years of life's development, at the final stage of evolution, man appeared on Earth. Modern paleontology traces the ancestors of man back for about 15 million years... How many planets in the Universe can there be like our Earth, inhabited by intelligent beings? Let's try to make an approximate calculation.
There are about 200 billion stars in the Galaxy. Including stars like our Sun - about 2 billion. Of these, at least every tenth star has planets orbiting, and the total number of planets located in the “habitable zone” is approximately 200 million. The number of planets on which favorable conditions have developed for the emergence of life can be estimated at 2 million. But on most planets, life for some reason came to a standstill, and only on 20 thousand planets did it develop further. However, it is not at all necessary that once life develops on a planet it becomes intelligent. The probability of such an outcome is no more than one in a thousand. Under this condition, there will be only... 20 planets with intelligent inhabitants!
In short, intelligent beings could one day appear on 20 planets in our Galaxy. But only on 10 of them were civilizations able to survive. A region of the Universe with a radius of about 15 billion light years is accessible to modern astronomical instruments. In this part of the Universe there are about 100 billion stellar “islands” - galaxies. It is not at all necessary that there are alien civilizations in each of them. Even if out of every ten galaxies only one has a single inhabited planet with intelligent beings, then even then the total number of civilizations in the Universe we observe will be a colossal figure - 10 billion!
True, for us this figure is purely speculative, because discovering such distant civilizations, and even more so establishing contact with them, is completely unrealistic. It should also be noted that the repetition of a long chain of random events and circumstances that led to the appearance of man on Earth is so unlikely that life on other planets is unlikely to develop according to the “earthly” version. Thus, the results of scientific research lead us to a very important thought: planet Earth is almost the unique carrier of Intelligence in the Galaxy, if, of course, we proceed from our purely earthly criteria and calculations.
It’s a shame that there are apparently only a few alien civilizations in our Galaxy. And if there are really only ten of them, then we can assume that: 3 civilizations are ahead of us in their development, 3 civilizations have reached our technical level, 3 civilizations are behind us in their development. Of particular interest to us should be those civilizations that have risen to the highest levels of scientific and technological progress. There can be no doubt that they have mastered the technology of radio communication on the scale of interstellar distances, and their spacecraft are already roaming the expanses of the Galaxy. Can we detect them? How to establish contact with them?
Radiophysicists believe that the most suitable way to establish contact between civilizations separated by the unimaginable abyss of space is to receive and transmit radio signals. Such communication has a great advantage: the signal travels at the maximum possible speed, equal to the speed of light. But due to the enormous distances, the intensity of radio signals should be negligible. Therefore, to “listen” to interstellar “voices,” the largest radio telescopes with huge antennas and highly sensitive equipment are used.
The problem of finding aliens
Let's assume that signals from inhabitants from another planet are received. Will we be able to understand their radio transmission? After all, we don’t know their language at all! Fortunately, the universal cosmic language is the language of mathematics, the laws of which are the same throughout the Universe. And the incoming signals can be a certain sequence of radio pulses, meaning, for example, numbers in the natural series - 1,2,3,4,5 and so on. Then it will immediately become clear that these signals are the cosmic call signs of our brothers in mind. Using pulse signals, you can transmit not only individual messages, but also certain images. It is assumed that all sentient beings are sighted. To do this, it is enough to send a series of “telepulses”, which can be easily expanded into the corresponding “picture”. Their line-by-line alternation allows you to build a contour image containing rich information. One day the problem of deciphering the language of another civilization will arise. Is it possible? Yes, it's possible. In recent years, mathematical linguistics has been developing rapidly in our country. With the help of a computer, ancient Mayan manuscripts were read, which for a long time could not be deciphered. We can assume that the languages of aliens will also be deciphered.
However, there is no need to think about the rapid exchange of information here. After all, if there are really only 10 civilizations in our Galaxy, then the average distances between them should be about 25 thousand light years. And the answer to the question sent by earthlings to one of them will be accepted by distant descendants. And in 50 thousand years, perhaps, any problem can be solved
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In the skies over Wyoming: a cloud or a "UFO"? What is it - a cloud or a "flying saucer"? We can say that it is both, although it is certainly not a ship of alien origin. Lenticular clouds may look like "flying saucers" |
UFOs and signs of a highly developed civilization |
This is what our Earth looks like at night when viewed from space. Can you find your favorite country or city? The most amazing thing is that this is quite possible thanks to city lights. It is easy to distinguish developed areas by lighting. |
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A way out of this impasse could be to send highly developed civilizations automatic stations to the nearest stars, where they listen to signals coming from inhabited planets. Then these stations enter into radio contact with the detected intelligent beings, transmit to them their stock of information, and report back information to their planet. True, they will not arrive very soon, but the other party will receive valuable information immediately, subject to contact. It can be assumed that such probe stations are already exploring the circumsolar space.
From the Solar System, we can search for alien civilizations only in that half of the Galaxy in which we ourselves are located. According to the above calculations, five civilizations were lost in this half of the galactic island. One of them is ours. Therefore, we have access to almost two or three civilizations from among those that have reached our level or are ahead of us in their development. And to find them, radio astronomers must literally search the entire sky. Now let’s try to imagine what the search for signals from intelligent beings is from a scientific and technical point of view. This is a sequential survey of the sky using the world's largest radio telescopes, as well as using the latest laser equipment. Such a review must be carried out day after day, month after month, year after year... and so on for tens, hundreds, thousands of years.
In a word, as long as humanity exists on Earth, systematic searches for radio signals from extraterrestrial civilizations should not stop. So, astrophysicists have calculated the number of planets on which life could have arisen; of which the proportion of planets with intelligent life; from among the latter - the proportion of planets where civilizations could achieve high technological development and learned to send intelligent signals to other worlds. If life in the Universe, similar to that on Earth, exists, then why don’t we observe it? We should be alarmed by the fact that no “manifestations of intelligent activity” of alien beings in the radio range have yet been discovered. Moreover, there are not even sources of radio emission that could be considered “suspicious.”
The high technical development of civilization is associated with the release of large amounts of energy into outer space. For example, the active radio engineering activity of mankind has led to the fact that for more than 80 years powerful radio stations, and subsequently television stations, have been continuously sending their signals onto the air. Due to this, the overall level of radio emission from the Earth has increased significantly. In terms of the power and nature of radio emission, our Earth has become strikingly different from the rest of the planets in the solar system. And currently, within a radius of more than 80 light years from us, news is spreading at the speed of light among the star worlds about the emergence of a technical civilization on Earth. If there are planets out there with intelligent beings observing their skies in radio rays, then they certainly should know about us. This is exactly how we would discover a technically advanced civilization. However, nothing like this can be discovered. Does this mean that intelligent life in our Galaxy has not reached a sufficiently high level of development anywhere? But it may be different: highly developed civilizations exist and send some special signals into the vastness of the Universe, but we do not yet have the equipment to receive them. It is quite possible that this is the case.
Recently, a very clear pattern has been observed: the further humanity penetrates into space, the more people are dissuaded from the existence of nearby extraterrestrial civilizations. Oases of intelligent life in the Universe are apparently not as common a phenomenon as previously thought. Most likely, the nearest planetary systems where thinking beings live are many thousands of light years away from us. A prominent researcher of the Universe, I. S. Shklovsky, who for many years dealt with the problem of radio-astronomical search for extraterrestrial civilizations, came to the following conclusion: if we adhere to the hypothesis about the existence of Earth-like civilizations that can send intelligent radio signals, then such call signs from civilizations located within our Galaxy were would have already been discovered. Since such signals are not observed, it must be recognized that there are very few technically advanced civilizations. It is quite possible that the earthly civilization is the only one in our Galaxy.
Note that I.S. Shklovsky does not speak about the complete absence of alien civilizations, but only about technologically advanced civilizations similar to ours. In this case, earthlings must take the first step: to establish a systematic sending of signals to the stars of our Galaxy. Now powerful generators of light beams - lasers - have been created. Laser technology will soon surpass radio as a method of transmitting information over long distances. And then humanity will use laser communication for interstellar communication.
Oleg Nikolaevich Korotsev, "Astronomy for everyone"
We are starting a new column, “Simply about the complex,” in which we will ask experts in various fields the simplest, sometimes even childishly naive questions about everything in the world. And our interlocutors will tolerate our importunity, speaking intelligibly and naturally about complex things. Today we are talking with Belarusian photographer and astronomer Viktor Malyshchits, well known to our readers from a series of articles on space.
Let's start with the most important thing. Where did the aliens go and why, despite all our efforts, have we still not found them (and they have not found us)?
In attempts to detect intelligent life forms, humanity uses radio signals. But we don’t know what type of communication they use. Maybe aliens don’t know about radio waves or have long abandoned them?
There are other questions. In what format should I send the signal? In what areas of space? How can you increase the likelihood that a signal will be understood? Many signaling events are PR campaigns. For example, in 1974, a radio signal was sent from the Arecibo Observatory towards the globular star cluster M13. Some people said that there are 100 thousand stars there, at least ten of them will have aliens! They just keep silent that this cluster is 24 thousand light years away. And don’t forget that the probable answer takes the same amount.
Part of Arecibo's message
It’s better to try to look for some signals yourself than to send them. However, neither one nor the other has yet produced any results.
- Space is boundless, the Universe is infinite. Why did scientists even come to this conclusion?
We assume that our world has a certain structure: there are galaxies, clusters of galaxies, superclusters of galaxies, etc. But on a scale of several hundred million light years, our world is homogeneous, and, as far as we can see, nothing changes there. There is no sign that the structure of the Universe is trying to cluster closer to some center or edge. Based on these observations, the conclusion is drawn that, probably, everything will continue to be the same.
The trouble is that no matter what telescopes we build, we cannot see the whole world. The maximum that we can see is those objects that are located at a distance of 13.7 billion light years from us (the age at which our Universe is estimated). The light from them has already reached us. But there could still be something going on, it’s just that the light signal didn’t have time to reach from there.
Thus, there is a boundary beyond which we cannot break. But we can only guess what’s behind it, extrapolating from the knowledge we have.
Why did people stop going to the moon? After all, today there are much more opportunities for this than 50 years ago. Maybe conspiracy theories don't lie?..
I don't believe in any conspiracy theories. The answer to the question is very simple: sending a man to the Moon is a very, very expensive project. In the 1960s, the geopolitical situation was different; the USA and the USSR actively participated in the space race. It was necessary to catch up and overtake the opponent, people wanted this, they were ready to give up material wealth in order to be first.
Today society has become more well-fed. We, of course, can now resume flights to the Moon, we can even fly to Mars. The only question is: how much will this cost taxpayers? We want to have a good job, a comfortable holiday, a brand new iPhone and everything else. Are people ready to give this up?
In addition, today's technology has reached such a level that a person is not needed; it is much cheaper to do without one. A person is a heavy piece of meat, in which only his head and arms work normally, and everything else is an extra burden, which, among other things, needs a bunch of life support systems. A small lunar rover with a bunch of sensors will weigh much less, it does not need oxygen and water, and it is much cheaper to launch it to the Moon than a human.
What color are planets and nebulae really? In photographs they are so beautiful and colorful, but when we look at the night sky or into space through a telescope, we do not see this colorful beauty.
The concept of color is very relative. For a person, this is not so much an absolute value as a relative one. How does the human eye work? It constantly adjusts the white balance. Here we are sitting in the office and see yellow light bulbs, while the sheet of paper under them looks white, and now everything outside the window is somehow blue. Let's go outside during the day, and everything there will seem white. This is because our eyes are constantly adjusting so that the background lighting is greyish. Therefore, it is very difficult to talk about color during the day; a lot depends on the background lighting. But at night, when there is no background lighting, our eye sets the white balance to a specific value.
Remember that the photoreceptors in the eye include cones and rods? It is the latter that are responsible for night vision, and they do not recognize colors in low light. Therefore, through a telescope we see the nebula as a kind of blurry, colorless haze. But for the camera it makes no difference whether the lighting is weak or strong, it always records the color.
Do you know what the most popular color among nebulae is? Pink! Nebulae are mostly made of hydrogen, which glows red, a little blue and violet under the influence of nearby stars - creating a pink color.
So space is colored, we just don’t see these colors. We can only discern the colors of the brightest stars and planets. Everyone, for example, sees that Mars is not green, but orange, Jupiter is yellowish, and Venus is white. When processing photographs, they try to match them to these colors and adjust them. Although there are no strict rules. Often, through telescopes or spacecraft, the planet is photographed in slightly different ranges, and not in standard RGB. Therefore, colors in photographs may not always be natural.
Hubble Telescope
The Rosette Nebula in the Hubble Palette
In general, there are two options with space footage. According to the first, they try to show objects as realistically as possible, they shoot in RGB, the nebulae turn out to be pink, the stars are of normal color. As a second example, we can cite such a technique as the “Hubble palette” (the name arose due to the fact that photographs from this telescope were first processed in this way). Elements such as oxygen, hydrogen, sulfur and some others glow only in certain ranges of the spectrum. There are special filters that can show, for example, only hydrogen or only sulfur. You put on a filter and only the structure of hydrogen in the nebula is recorded; you put on another one and you see only oxygen. This is important for an astronomer because the distribution of different chemical elements can be traced. But how to show all this to people? Then, purely arbitrarily, they decide to color hydrogen green, sulfur red, and oxygen blue. The result is a beautiful and at the same time informative picture, which, however, has little in common with the original.
Why are large asteroids discovered so late? After all, people often learn about them only when they are already as close as possible to the Earth.
Let's figure out how asteroids are discovered in general. The same area of the starry sky is photographed several times. If any “star” moves, it means it is an asteroid or something similar. Next you need to check the databases, calculate the orbit and see if the object will collide with the planet.
The problem is that an asteroid dangerous to Earth is just a boulder with a diameter of a couple of tens of meters. It is very difficult to see a 20-30 meter block in space. Plus they are practically black.
I would say that, on the contrary, we should be proud that people learned to detect asteroids so early. Previously, even the most terrible of them were discovered only after they flew past.
- Is there a lot of space debris in orbit? How dangerous is he?
A lot of! And the biggest problem is that we can’t do anything with it yet. You can only try not to throw anything into space or throw it away so that it burns up in the atmosphere. In low orbits, where there are most satellites, including broken ones, the earth's atmosphere is slightly present and gradually slows down the movement of debris. It eventually falls to Earth and burns up in the atmosphere.
What to do with higher orbits? If the amount of debris reaches a critical value, an avalanche-like formation of debris will begin. Imagine that some particle collides with a satellite at incredible speed - it will also scatter into hundreds of pieces that will collide with other particles, etc. As a result, the planet will be surrounded by a cocoon of debris, and space will become unsuitable for research. Fortunately, we are still far from reaching this critical value.
- Why do people get hysteria about the planet Nibiru? Have you, as an experienced astronomer, seen it?
People love to believe in conspiracy theories. This is our psychology, we want to believe in the unreal. No one has really seen this planet; astronomers do not take it seriously.
- Why didn’t they come up with artificial gravity? She is in all science fiction films!
Physics has not yet been discovered! Theoretically, of course, it is possible to build a huge ring in space that spins at a certain speed. Then, due to the centrifugal force, gravity can be obtained. But all this is more fantasy than reality. For now, it’s easier to teach people to work in zero gravity.
A galaxy is a large formation of stars, gas, and dust that is held together by gravity. These largest compounds in the Universe can vary in shape and size. Most space objects are part of a particular galaxy. These are stars, planets, satellites, nebulae, black holes and asteroids. Some of the galaxies have large amounts of invisible dark energy. Due to the fact that galaxies are separated by empty space, they are figuratively called oases in the cosmic desert.
| Elliptical galaxy | Spiral galaxy | Wrong galaxy | |
|---|---|---|---|
| Spheroidal component | The entire galaxy | Eat | Very weak |
| Star disk | None or weakly expressed | Main component | Main component |
| Gas and dust disk | No | Eat | Eat |
| Spiral branches | No or only near the core | Eat | No |
| Active cores | Meet | Meet | No |
| 20% | 55% | 5% |
Our galaxy
The closest star to us, the Sun, is one of the billion stars in the Milky Way galaxy. Looking at the starry night sky, it’s hard not to notice a wide strip strewn with stars. The ancient Greeks called the cluster of these stars the Galaxy.
If we had the opportunity to look at this star system from the outside, we would notice an oblate ball in which there are over 150 billion stars. Our galaxy has dimensions that are hard to imagine. A ray of light travels from one side to the other for hundreds of thousands of Earth years! The center of our Galaxy is occupied by a core, from which huge spiral branches filled with stars extend. The distance from the Sun to the core of the Galaxy is 30 thousand light years. The solar system is located on the outskirts of the Milky Way.
Stars in the Galaxy, despite the huge accumulation of cosmic bodies, are rare. For example, the distance between the nearest stars is tens of millions of times greater than their diameters. It cannot be said that stars are scattered randomly in the Universe. Their location depends on the gravitational forces that hold the celestial body in a certain plane. Stellar systems with their own gravitational fields are called galaxies. In addition to stars, the galaxy includes gas and interstellar dust.
Composition of galaxies.
The Universe is also made up of many other galaxies. The closest ones to us are distant at a distance of 150 thousand light years. They can be seen in the sky of the southern hemisphere in the form of small foggy spots. They were first described by Pigafett, a member of the Magellanic expedition around the world. They entered science under the name of the Large and Small Magellanic Clouds.
The closest galaxy to us is the Andromeda Nebula. It is very large in size, so it is visible from Earth with ordinary binoculars, and in clear weather, even with the naked eye.
The very structure of the galaxy resembles a giant spiral convex in space. On one of the spiral arms, ¾ of the distance from the center, is the Solar System. Everything in the galaxy revolves around the central core and is subject to the force of its gravity. In 1962, astronomer Edwin Hubble classified galaxies depending on their shape. The scientist divided all galaxies into elliptical, spiral, irregular and barred galaxies.
In the part of the Universe accessible to astronomical research, there are billions of galaxies. Collectively, astronomers call them the Metagalaxy.
Galaxies of the Universe
Galaxies are represented by large groups of stars, gas, and dust held together by gravity. They can vary significantly in shape and size. Most space objects belong to some galaxy. These are black holes, asteroids, stars with satellites and planets, nebulae, neutron satellites.
Most galaxies in the Universe contain enormous amounts of invisible dark energy. Since the space between different galaxies is considered empty, they are often called oases in the void of space. For example, a star called the Sun is one of the billions of stars in the Milky Way galaxy located in our Universe. The Solar System is located ¾ of the distance from the center of this spiral. In this galaxy, everything constantly moves around the central core, which obeys its gravity. However, the core also moves with the galaxy. At the same time, all galaxies move at super speeds.
Astronomer Edwin Hubble in 1962 carried out a logical classification of the galaxies of the Universe, taking into account their shape. Now galaxies are divided into 4 main groups: elliptical, spiral, barred and irregular galaxies.
What is the largest galaxy in our Universe?
The largest galaxy in the Universe is a supergiant lenticular galaxy located in the Abell 2029 cluster.
Spiral galaxies
They are galaxies whose shape resembles a flat spiral disk with a bright center (core). The Milky Way is a typical spiral galaxy. Spiral galaxies are usually called with the letter S; they are divided into 4 subgroups: Sa, So, Sc and Sb. Galaxies belonging to the So group are distinguished by bright nuclei that do not have spiral arms. As for the Sa galaxies, they are distinguished by dense spiral arms tightly wound around the central core. The arms of Sc and Sb galaxies rarely surround the core.
Spiral galaxies of the Messier catalog
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Barred galaxies
Bar galaxies are similar to spiral galaxies, but have one difference. In such galaxies, spirals begin not from the core, but from the bridges. About 1/3 of all galaxies fall into this category. They are usually designated by the letters SB. In turn, they are divided into 3 subgroups Sbc, SBb, SBa. The difference between these three groups is determined by the shape and length of the jumpers, where, in fact, the arms of the spirals begin.
Spiral galaxies with the Messier catalog bar
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Elliptical galaxies
The shape of galaxies can vary from perfectly round to elongated oval. Their distinguishing feature is the absence of a central bright core. They are designated by the letter E and are divided into 6 subgroups (according to shape). Such forms are designated from E0 to E7. The former have an almost round shape, while the E7 are characterized by an extremely elongated shape.
Elliptical galaxies of the Messier catalog
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Irregular galaxies
They do not have any pronounced structure or shape. Irregular galaxies are usually divided into 2 classes: IO and Im. The most common is the Im class of galaxies (it has only a slight hint of structure). In some cases, helical residues are visible. IO belongs to the class of galaxies that are chaotic in shape. The Small and Large Magellanic Clouds are a prime example of the Im class.
Irregular galaxies of the Messier catalog
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Table of characteristics of the main types of galaxies
| Elliptical galaxy | Spiral galaxy | Wrong galaxy | |
| Spheroidal component | The entire galaxy | Eat | Very weak |
| Star disk | None or weakly expressed | Main component | Main component |
| Gas and dust disk | No | Eat | Eat |
| Spiral branches | No or only near the core | Eat | No |
| Active cores | Meet | Meet | No |
| Percentage of total galaxies | 20% | 55% | 5% |
Large portrait of galaxies
Not long ago, astronomers began working on a joint project to identify the location of galaxies throughout the Universe. Their goal is to obtain a more detailed picture of the overall structure and shape of the Universe on large scales. Unfortunately, the scale of the universe is difficult for many people to comprehend. Take our galaxy, which consists of more than a hundred billion stars. There are billions more galaxies in the Universe. Distant galaxies have been discovered, but we see their light as it was almost 9 billion years ago (we are separated by such a great distance).
Astronomers learned that most galaxies belong to a certain group (it became known as a “cluster”). The Milky Way is part of a cluster, which in turn consists of forty known galaxies. Typically, most of these clusters are part of an even larger grouping called superclusters.
Our cluster is part of a supercluster, which is commonly called the Virgo cluster. Such a massive cluster consists of more than 2 thousand galaxies. At the time when astronomers created a map of the location of these galaxies, superclusters began to take a concrete form. Large superclusters have gathered around what appear to be giant bubbles or voids. What kind of structure this is, no one yet knows. We don't understand what might be inside these voids. According to the assumption, they may be filled with a certain type of dark matter unknown to scientists or have empty space inside. It will be a long time before we know the nature of such voids.
Galactic Computing
Edwin Hubble is the founder of galactic exploration. He is the first to determine how to calculate the exact distance to a galaxy. In his research, he relied on the method of pulsating stars, which are better known as Cepheids. The scientist was able to notice the connection between the period needed to complete one pulsation of brightness and the energy that the star releases. The results of his research became a major breakthrough in the field of galactic research. In addition, he discovered that there is a correlation between the red spectrum emitted by a galaxy and its distance (the Hubble constant).
Nowadays, astronomers can measure the distance and speed of a galaxy by measuring the amount of redshift in the spectrum. It is known that all galaxies in the Universe are moving away from each other. The farther a galaxy is from Earth, the greater its speed of movement.
To visualize this theory, just imagine yourself driving a car moving at a speed of 50 km per hour. The car in front of you is driving 50 km per hour faster, which means that its speed is 100 km per hour. There is another car in front of him, which is moving faster by another 50 km per hour. Even though the speed of all 3 cars will be different by 50 km per hour, the first car is actually moving away from you 100 km per hour faster. Since the red spectrum speaks about the speed of the galaxy moving away from us, the following is obtained: the greater the red shift, the faster the galaxy moves and the greater its distance from us.
We now have new tools to help scientists search for new galaxies. Thanks to the Hubble Space Telescope, scientists were able to see what they could only dream of before. The high power of this telescope provides good visibility of even small details in nearby galaxies and allows you to study more distant ones that have not yet been known to anyone. Currently, new space observation instruments are under development, and in the near future they will help to gain a deeper understanding of the structure of the Universe.
Types of galaxies
- Spiral galaxies. The shape resembles a flat spiral disk with a pronounced center, the so-called core. Our Milky Way galaxy falls into this category. In this section of the portal site you will find many different articles describing space objects of our Galaxy.
- Barred galaxies. They resemble spiral ones, only they differ from them in one significant difference. The spirals do not extend from the core, but from the so-called jumpers. One third of all galaxies in the Universe can be attributed to this category.
- Elliptical galaxies have different shapes: from perfectly round to oval elongated. Compared to spiral ones, they lack a central, pronounced core.
- Irregular galaxies do not have a characteristic shape or structure. They cannot be classified into any of the types listed above. There are much fewer irregular galaxies in the vastness of the Universe.
Astronomers have recently launched a joint project to identify the location of all the galaxies in the Universe. Scientists hope to get a clearer picture of its structure on a large scale. The size of the Universe is difficult for human thought and understanding to estimate. Our galaxy alone is a collection of hundreds of billions of stars. And there are billions of such galaxies. We can see light from discovered distant galaxies, but not even imply that we are looking into the past, because the light beam reaches us over tens of billions of years, such a great distance separates us.
Astronomers also associate most galaxies with certain groups called clusters. Our Milky Way belongs to a cluster that consists of 40 explored galaxies. Such clusters are combined into large groups called superclusters. The cluster with our galaxy is part of the Virgo supercluster. This giant cluster contains more than 2 thousand galaxies. After scientists began to draw a map of the location of these galaxies, superclusters acquired certain shapes. Most galactic superclusters were surrounded by giant voids. No one knows what could be inside these voids: outer space like interplanetary space or a new form of matter. It will take a long time to solve this mystery.
Interaction of galaxies
No less interesting for scientists is the question of the interaction of galaxies as components of cosmic systems. It's no secret that space objects are in constant motion. Galaxies are no exception to this rule. Some types of galaxies could cause a collision or merger of two cosmic systems. If you understand how these space objects appear, large-scale changes as a result of their interaction become more understandable. During the collision of two space systems, a gigantic amount of energy splashes out. The meeting of two galaxies in the vastness of the Universe is an even more probable event than the collision of two stars. Collisions of galaxies do not always end with an explosion. A small space system can freely pass by its larger counterpart, changing its structure only slightly.
Thus, formations are formed that are similar in appearance to elongated corridors. They contain stars and gas zones, and new stars are often formed. There are times when galaxies do not collide, but only lightly touch each other. However, even such an interaction triggers a chain of irreversible processes that lead to huge changes in the structure of both galaxies.
What future awaits our galaxy?
As scientists suggest, it is possible that in the distant future the Milky Way will be able to absorb a tiny cosmic-sized satellite system, which is located at a distance of 50 light years from us. Research shows that this satellite has a long life potential, but if it collides with its giant neighbor, it will most likely end its separate existence. Astronomers also predict a collision between the Milky Way and the Andromeda Nebula. Galaxies move towards each other at the speed of light. The wait for a probable collision is approximately three billion Earth years. However, whether it will actually happen now is difficult to speculate due to the lack of data on the movement of both space systems.
Description of galaxies onKvant. Space
The portal site will take you to the world of interesting and fascinating space. You will learn the nature of the structure of the Universe, become familiar with the structure of famous large galaxies and their components. By reading articles about our galaxy, we become more clear about some of the phenomena that can be observed in the night sky.
All galaxies are at a great distance from Earth. Only three galaxies can be seen with the naked eye: the Large and Small Magellanic Clouds and the Andromeda Nebula. It is impossible to count all the galaxies. Scientists estimate that their number is about 100 billion. The spatial distribution of galaxies is uneven - one region may contain a huge number of them, while the second will not contain even a single small galaxy. Astronomers were unable to separate images of galaxies from individual stars until the early 90s. At this time, there were about 30 galaxies with individual stars. All of them were assigned to the Local Group. In 1990, a majestic event took place in the development of astronomy as a science - the Hubble Telescope was launched into Earth orbit. It was this technique, as well as new ground-based 10-meter telescopes, that made it possible to see a significantly larger number of resolved galaxies.
Today, the “astronomical minds” of the world are scratching their heads about the role of dark matter in the construction of galaxies, which manifests itself only in gravitational interaction. For example, in some large galaxies it makes up about 90% of the total mass, while dwarf galaxies may not contain it at all.
Evolution of galaxies
Scientists believe that the emergence of galaxies is a natural stage in the evolution of the Universe, which took place under the influence of gravitational forces. Approximately 14 billion years ago, the formation of protoclusters in the primary substance began. Further, under the influence of various dynamic processes, the separation of galactic groups took place. The abundance of galaxy shapes is explained by the diversity of initial conditions in their formation.
The contraction of the galaxy takes about 3 billion years. Over a given period of time, the gas cloud turns into a star system. Star formation occurs under the influence of gravitational compression of gas clouds. After reaching a certain temperature and density in the center of the cloud, sufficient for the start of thermonuclear reactions, a new star is formed. Massive stars are formed from thermonuclear chemical elements that are more massive than helium. These elements create the primary helium-hydrogen environment. During enormous supernova explosions, elements heavier than iron are formed. It follows from this that the galaxy consists of two generations of stars. The first generation is the oldest stars, consisting of helium, hydrogen and very small amounts of heavy elements. Second-generation stars have a more noticeable admixture of heavy elements because they form from primordial gas enriched in heavy elements.
In modern astronomy, galaxies as cosmic structures are given a special place. The types of galaxies, the features of their interaction, similarities and differences are studied in detail, and a forecast of their future is made. This area still contains a lot of unknowns that require additional study. Modern science has resolved many questions regarding the types of construction of galaxies, but there are also many blank spots associated with the formation of these cosmic systems. The current pace of modernization of research equipment and the development of new methodologies for studying cosmic bodies give hope for a significant breakthrough in the future. One way or another, galaxies will always be at the center of scientific research. And this is based not only on human curiosity. Having received data on the patterns of development of cosmic systems, we will be able to predict the future of our galaxy called the Milky Way.
The most interesting news, scientific, and original articles about the study of galaxies will be provided to you by the website portal. Here you can find exciting videos, high-quality images from satellites and telescopes that will not leave you indifferent. Dive into the world of unknown space with us!
Planetary scientists from the United States have begun a large-scale search for advanced extraterrestrial civilizations in the Andromeda Nebula, observing flares near its stars that may be artificially created. This was announced the day before at a meeting of NASA employees dedicated to the detection of man-made traces of aliens.
“We believe that there are civilizations in the Universe that are no less developed than us. They are capable of producing special laser installations, with the help of which they will announce themselves to the inhabitants of the Earth and other brothers in mind. If such a laser functions for a long time, then, most likely, we will find it,” said Andrew Stewart, an employee of the University of California (Santa Barbara, USA).
The famous American astronomer Frank Drake, more than 50 years ago, created a formula that calculated the number of civilizations in the Milky Way with which it is likely to come into contact. Thus, the specialist tried to understand what the chances of meeting aliens are.
According to the developed formula, there are quite a lot of extraterrestrial civilizations in the Galaxy. After some time, the Italian physicist Enrico Fermi spoke out, noting a very strange point: the Milky Way is practically “teeming” with civilizations, but the long-awaited meeting with their representatives never happened, not even any traces were found. The scientist’s arguments are now known as the Fermi Paradox, which has haunted humanity for many decades.
During this time, many different versions have been put forward, one of the most popular is the theory of a “unique Earth”. Its supporters believe that conditions identical to those on Earth are required for the emergence of developed organisms. Essentially, what we need here is a clone of our planet.
There is also an opinion among scientists that the wanted civilizations disappear too quickly, so they cannot be discovered. But we cannot discount the fact that the aliens are simply hiding for some reason, and they are doing it very skillfully.
Andrew Stewart, Philip Lubin and their assistants believe that to increase the chances of success, one should look for aliens not only in our galaxy, but in others too. In addition, searches should be carried out not in the radio wave range, but in the optical, and this is accompanied by a number of reasons. First of all, light flashes, for example, laser flashes, emanating from certain luminaries, are much easier to record and separate from the natural radiation of other space objects. In addition, this property of light signals makes it possible to observe immediately an uncountable number of star systems of other galaxies.
The scientific team chose the Andromeda Nebula, which is the closest galaxy of the Milky Way, for observations using a new method. These two structures have many similarities both in structure and size. This large-scale work uses 30 telescopes, each of which monitors a different part of the galaxy.
Philip Lubin believes that there are more than a trillion planets in the Andromeda Nebula, and there is a possibility that at least one of them has intelligent beings that have already reached the level of development to get out into space and begin to look for other civilizations.
To protect such a structure from destruction under the influence of unbearable temperatures, the use of some kind of liquid cooling system would most likely be required. Such a translator design, according to scientists, would be far beyond our technological capabilities, but nevertheless would not violate the laws of physics known to us, which is good in itself.
As for the purposes for which an extraterrestrial civilization could build such a device, then, according to scientists, it could be used as an interstellar or even intergalactic signaling system, informing other intelligent life forms about the existence of another civilization.
“You can also imagine an emitter that creates directed radio waves and can be used as a kind of light sail. Similar to a sail that is driven by the wind, a light sail gets its momentum from light energy, theoretically allowing it to accelerate to the speed of light,” Loeb continues.
To be able to create the necessary impulse and accelerate the light sail, such an emitter must have incredible power. It is possible that this power level is so great that it is enough to accelerate objects weighing several million tons (think of 20 huge cruise ships as an example). According to Manasvi Lingram, such an emitter will be able to send huge spaceships with passengers on interstellar or even intergalactic travel.
Interestingly, our civilization also plans to use light sails for interstellar travel in the near future, albeit on a much smaller scale. Theoretical physicist and Russian billionaire Yuri Milner thinks it's a great idea and decided to invest $100 million in the Breakthrough Starshot project last year. And earlier this year, scientists from the Max Planck Institute used a solar sail device to study Alpha Centauri, which is the closest star system to us.
That is, scientists are leading to the conclusion that the FRB flares that we detect on Earth may be a “leak” or side emission from an alien system that creates these impulses to accelerate alien spacecraft.
“Radio beams cross different parts of our sky because their source changes its location relative to us,” Loeb explains.
“This may be due to the peculiarity of the rotation of the object generating this energy, or to the very rotation of the star or the entire galaxy as a whole where this source is located. From time to time, the rays are sent straight to the Earth and at the same time confuse our astronomers.”
Be that as it may, such an explanation was enough for Loeb and Lingham’s work to be accepted for publication in the scientific journal Astrophysical Journal Letters.
It is clear that much more work needs to be done and more convincing evidence must be collected. Yet many scientists agree that these signals are very strange. For example, Andrew Simeon, director of the SETI Research Institute, points out that these FRB signals, like nothing else, force scientists to consider a variety of different and sometimes even fantastic and crazy ideas about their source. Simeon, who was not involved in the study discussed today, supports the Harvard astronomers' work, even if it takes a somewhat unconventional approach.
“We cannot rule out the possibility that anomalous signals, like these fast radio pulses, could be created by extraterrestrial technology. And although this is unlikely, the idea should still be a possibility that should not be dismissed out of hand,” says Simeon.
“Lingram and Loeb's work offers an intriguing idea about a special technology beyond our understanding of traditional forms of communications or radar systems (directed energy transmission systems) capable of producing short-duration radio pulses. And although this option in itself is very controversial, it provides an excellent example of the fact that in such discussions we should be open to absolutely any proposals and assumptions, especially when it comes to the search for potential signals from extraterrestrial civilizations.”
Despite this remark by Simeon, the new hypothesis should not be considered anything more than another assumption trying to explain the nature of strange radio pulses, so it would be foolish to draw any conclusions now. Nowadays there is a general tendency - both in the media and among the public - to draw conclusions ahead of time. As one of the latest examples, we can consider very, all the information about which one way or another came down to theories about aliens, rather than to something more scientific and substantiated from the point of view of astrophysics.
Loeb agrees that his hypothesis may sound too fantastical, but according to the scientist, it should not be ruled out simply because it may sound too bizarre to some.
“One of the most amazing things about doing science is that one can rule out a possibility only after providing enough convincing evidence for a better idea,” says Loeb.
“Science has many examples showing the unwiseness of ruling out a wide variety of possibilities solely on the basis of one's prejudices, since in the end this always leads to stagnation, not progress. Even if it seems to me that based on the collected data it is possible to infer an artificial source of the FRB signals, I would have no problem accepting a different explanation for this phenomenon if I were provided with more accurate data. Science is the experience of knowledge. We figure out how nature works by rejecting the wrong ones based on our observations rather than our preconceptions."
