In interstellar and interplanetary space there are small particles of solids - that which in Everyday life we call dust. We call the accumulation of these particles cosmic dust in order to distinguish it from dust in the terrestrial sense, although they physical structure similar. These are particles ranging in size from 0.000001 centimeters to 0.001 centimeters, the chemical composition of which, in general, is still unknown.

These particles often form clouds, which are detected in different ways. For example, in our planetary system, the presence of cosmic dust was discovered due to the fact that sunlight, scattering on it, causes a phenomenon that has long been known as "zodiacal light". We observe the zodiacal light only in clear nights in the form of a faintly luminous band stretching in the sky along the Zodiac, it gradually weakens as we move away from the Sun (which is at this time beyond the horizon). Measurements of the intensity of the zodiacal light and study of its spectrum show that it comes from the scattering of sunlight on particles that form a cloud of cosmic dust, surround the Sun and reach the orbit of Mars (Earth is thus inside a cloud of cosmic dust).
The presence of clouds of cosmic dust in interstellar spaces is detected in the same way.
If any cloud of dust comes close to a relatively bright star, then the light from this star will be scattered on the cloud. We then find this cloud of dust in the form of a bright speck called "irregular nebula" (diffuse nebula).
Sometimes a cloud of cosmic dust becomes visible because it obscures the stars behind it. Then we distinguish it in the form of a relatively dark spot against the background of a sky dotted with stars.
A third way to detect cosmic dust is to change the color of stars. Stars that are behind a cloud of cosmic dust are, in general, more intensely red. Cosmic dust, just like terrestrial dust, causes "reddening" of the light that passes through it. We can often observe this phenomenon on Earth. On foggy nights, we see that the lanterns located at a distance from us are more reddened than the nearby lanterns, the light of which remains practically unchanged. However, we must make a reservation: only dust consisting of small particles causes a change in color. And it is precisely such dust that is most often found in interstellar and interplanetary spaces. And from the fact that this dust causes the "reddening" of the light of the stars lying behind it, we conclude that the size of its particles is small, about 0.00001 cm.
We don't know exactly where cosmic dust comes from. Most likely, it arises from those gases that are constantly thrown out by stars, especially young ones. Gas at low temperatures freezes and turns into a solid body - into particles of cosmic dust. And, conversely, part of this dust, finding itself in a relatively high temperature, for example, close to some hot star, or during the collision of two clouds of cosmic dust, which, generally speaking, is not uncommon in our region of the Universe, turns into gas again.

That the cosmic vacuum is not as empty as the layman believes, we still cannot but note that it can hardly be called “filled” either. Hydrogen, calcium, iron - all this is in the space environment, but in such quantities that it is useless to even try to search without accurate equipment.

It is not surprising that even before 1930, most scientists were convinced that there was no medium in the space between stars that would cause noticeable absorption of starlight. Therefore, when determining the distance to any star, they used the well-known law of weakening the brilliance of the light source in proportion to the square of the distance to it. However, in doing so, the scientists made a terrible mistake.

The point is that this proposition, which is valid in the case of a completely transparent space, turns out to be incorrect in the case of the presence of an absorbing medium. And the fact that the space between the stars is not completely transparent was pointed out a hundred years ago by the outstanding Russian scientist V. Ya. Struve, but his ideas were not appreciated by his contemporaries.

Fortunately, in the early 1930s, the scientist was proven right. Now no one called space a completely transparent void, and the fault of distortions not taken into account by scientists of the past was nothing more than space dust.

Since then, astronomers have begun to study the distribution of absorbing matter in space in the most thorough way, to investigate how it changes the visible color and brightness of stars. Without taking this phenomenon into account, all further reasoning about the structure of the stellar world cannot be correct.

Cosmic dust not only distorts the distances in space, but also distorts our understanding of the stars. The phenomenon of the reddening of stars, due to which the stars seem to us relatively colder than they really are, is entirely the "merit" of cosmic dust.

Interstellar dust is not a medium of uniform density and consists of separate clouds, the average size of which is such that light travels from one edge to the other for ten years, that is, the size of these clouds is much larger than the average distance between stars.

It has long been known that in the world space between the stars there are huge clouds of rarefied matter, some of which are gas, while others are dusty. Clouds of cosmic dust shine by the reflected light of those stars that are located near them.

However, the question of whether there is anything in common between these bright dusty nebulae and the absorbing interstellar medium, which also consists of clouds, was not completely clear.

Some features of large clouds of dark dust, the so-called dark nebulae, are revealed due to the fact that they absorb the light of the stars behind them and form, as it were, dips of complete blackness against a shining background.

As a result, it was proved that all the differences between "dark" and "light" dusty nebulae consist only in the fact that the latter are in the neighborhood of very bright stars that illuminate them strongly enough to be visible, and the former are such "lights" are devoid of.

Thus, there was no significant difference between bright and dark clouds of cosmic dust, and the question of how they appear to us depends solely on their random location in relation to bright stars.

Cosmic dust, its composition and properties are little known to a person who is not associated with the study of extraterrestrial space. However, such a phenomenon leaves its traces on our planet! Let us consider in more detail where it comes from and how it affects life on Earth.

The concept of space dust

Cosmic dust on Earth is most often found in certain layers of the ocean floor, ice sheets of the polar regions of the planet, peat deposits, hard-to-reach places in the desert and meteorite craters. The size of this substance is less than 200 nm, which makes its study problematic.

Usually the concept of cosmic dust includes the delimitation of the interstellar and interplanetary varieties. However, all this is very conditional. The most convenient option for studying this phenomenon is the study of dust from space at the boundaries solar system or beyond.

The reason for this problematic approach to the study of the object is that the properties of extraterrestrial dust change dramatically when it is near a star like the Sun.

Theories on the origin of cosmic dust

Streams of cosmic dust constantly attack the surface of the Earth. The question arises where this substance comes from. Its origin gives rise to many discussions among specialists in this field.

There are such theories of the formation of cosmic dust:

• Decay celestial bodies . Some scientists believe that space dust is nothing more than the result of the destruction of asteroids, comets and meteorites.
• The remnants of a protoplanetary type cloud. There is a version according to which cosmic dust is referred to as microparticles of a protoplanetary cloud. However, such an assumption raises some doubts due to the fragility of a finely dispersed substance.
• The result of the explosion on the stars. As a result of this process, according to some experts, there is a powerful release of energy and gas, which leads to the formation of cosmic dust.
• Residual phenomena after the formation of new planets. The so-called construction "garbage" has become the basis for the occurrence of dust.

According to some studies, a certain part of the cosmic dust component predated the formation of the solar system, which makes this material even more interesting for further study. It is worth paying attention to this when evaluating and analyzing such an extraterrestrial phenomenon.

The main types of cosmic dust

There is currently no specific classification of cosmic dust types. Subspecies can be distinguished by visual characteristics and location of these microparticles.

Consider seven groups of cosmic dust in the atmosphere, different in external indicators:

1. gray wreckage irregular shape. These are residual phenomena after the collision of meteorites, comets and asteroids no larger than 100-200 nm in size.
2. Particles of slag-like and ash-like formation. Such objects are difficult to identify solely by outward signs, because they have undergone changes, having passed through the atmosphere of the Earth.
3. The grains are round in shape, which are similar in parameters to black sand. Outwardly, they resemble powder of magnetite (magnetic iron ore).
4. Small black circles with a characteristic sheen. Their diameter does not exceed 20 nm, which makes their study a painstaking task.
5. Larger balls of the same color with a rough surface. Their size reaches 100 nm and makes it possible to study their composition in detail.
6. Balls of a certain color with a predominance of black and white tones with inclusions of gas. These microparticles of cosmic origin consist of a silicate base.
7. Spheres of heterogeneous structure made of glass and metal. Such elements are characterized by microscopic dimensions within 20 nm.

According to the astronomical location, 5 groups of cosmic dust are distinguished:

• Dust found in intergalactic space. This view can distort the size of distances in certain calculations and is able to change the color of space objects.
• Formations within the Galaxy. The space within these limits is always filled with dust from the destruction of cosmic bodies.
• Matter concentrated between stars. It is most interesting due to the presence of a shell and a core of a solid consistency.
• Dust located near a certain planet. It is usually located in the ring system of a celestial body.
• Clouds of dust around the stars. They circle the orbital path of the star itself, reflecting its light and creating a nebula.

Three groups according to the total specific gravity of microparticles look like this:

1. metal group. Representatives of this subspecies have a specific gravity of more than five grams per cubic centimeter, and their basis consists mainly of iron.
2. silicate group. The basis - clear glass with a specific gravity of approximately three grams per cubic centimeter.
3. Mixed group. The very name of this association indicates the presence of both glass and iron in the structure of microparticles. The base also includes magnetic elements.

Four groups according to the similarity of the internal structure of cosmic dust microparticles:

• Spherules with hollow filling. This species is often found in places where meteorites fall.
• Spherules of metal formation. This subspecies has a core of cobalt and nickel, as well as a shell that has oxidized.
• Spheres of uniform addition. Such grains have an oxidized shell.
• Balls with a silicate base. The presence of gas inclusions gives them the appearance of ordinary slags, and sometimes foam.

It should be remembered that these classifications are very arbitrary, but they serve as a certain guideline for designating types of dust from space.

Composition and characteristics of the components of cosmic dust

Let's take a closer look at what cosmic dust is made of. There is a problem in determining the composition of these microparticles. Unlike gaseous substances, solid bodies have a continuous spectrum with relatively few bands that are blurred. As a result, the identification of cosmic dust grains is difficult.

The composition of cosmic dust can be considered on the example of the main models of this substance. These include the following subspecies:

1. Ice particles, the structure of which includes a core with a refractory characteristic. The shell of such a model consists of light elements. In particles of large size there are atoms with elements of magnetic properties.
2. Model MRN, the composition of which is determined by the presence of silicate and graphite inclusions.
3. Oxide space dust, which is based on diatomic oxides of magnesium, iron, calcium and silicon.

General classification according to chemical composition space dust:

• Balls with a metallic nature of education. The composition of such microparticles includes such an element as nickel.
• Metal balls with the presence of iron and the absence of nickel.
• Circles on a silicone basis.
• Irregular-shaped iron-nickel balls.

More specifically, you can consider the composition of cosmic dust on the example found in oceanic silt, sedimentary rocks and glaciers. Their formula will differ little from one another. Findings in the study of the seabed are balls with a silicate and metal base with the presence of such chemical elements like nickel and cobalt. Also, microparticles with the presence of aluminum, silicon and magnesium were found in the bowels of the water element.

Soils are fertile for the presence of cosmic material. Especially a large number of spherules were found in places where meteorites fell. They were based on nickel and iron, as well as various minerals such as troilite, cohenite, steatite and other components.

Glaciers also hide aliens from outer space in the form of dust in their blocks. Silicate, iron and nickel serve as the basis for the found spherules. All mined particles were classified into 10 clearly demarcated groups.

Difficulties in determining the composition of the studied object and differentiating it from impurities of terrestrial origin leave this issue open for further research.

The influence of cosmic dust on life processes

The influence of this substance has not been fully studied by specialists, which provides great opportunities in terms of further activities in this direction. At a certain height, using rockets, they discovered a specific belt consisting of cosmic dust. This gives grounds to assert that such an extraterrestrial substance affects some of the processes occurring on planet Earth.

Influence of cosmic dust on the upper atmosphere

Recent studies suggest that the amount of cosmic dust can affect the change in the upper atmosphere. This process is very significant, because it leads to certain fluctuations in climatic characteristics planet Earth.

A huge amount of dust from the collision of asteroids fills the space around our planet. Its amount reaches almost 200 tons per day, which, according to scientists, cannot but leave its consequences.

Most susceptible to this attack, according to the same experts, North hemisphere, the climate of which is predisposed to cold temperatures and dampness.

The impact of cosmic dust on cloud formation and climate change is not well understood. New research in this area gives rise to more and more questions, the answers to which have not yet been received.

Influence of dust from space on the transformation of oceanic silt

Irradiation of cosmic dust by the solar wind leads to the fact that these particles fall to the Earth. Statistics show that the lightest of the three isotopes of helium in huge number falls through dust particles from space into oceanic silt.

The absorption of elements from space by minerals of ferromanganese origin served as the basis for the formation of unique ore formations on the ocean floor.

At the moment, the amount of manganese in areas that are close to the Arctic Circle is limited. All this is due to the fact that cosmic dust does not enter the World Ocean in those areas due to ice sheets.

Influence of cosmic dust on the composition of the ocean water

If we consider the glaciers of Antarctica, they amaze with the number of meteorite remains found in them and the presence of cosmic dust, which is a hundred times higher than the usual background.

An excessively high concentration of the same helium-3, valuable metals in the form of cobalt, platinum and nickel, makes it possible to assert with certainty the fact of the intervention of cosmic dust in the composition of the ice sheet. At the same time, the substance of extraterrestrial origin remains in its original form and not diluted by the waters of the ocean, which in itself is a unique phenomenon.

According to some scientists, the amount of cosmic dust in such peculiar ice sheets over the past million years is on the order of several hundred trillion formations of meteorite origin. During the period of warming, these covers melt and carry elements of cosmic dust into the World Ocean.

Watch a video about space dust:

This cosmic neoplasm and its influence on some factors of the vital activity of our planet have not yet been studied enough. It is important to remember that the substance can affect climate change, the structure of the ocean floor and the concentration of certain substances in the waters of the oceans. Photographs of cosmic dust testify to how many more mysteries these microparticles are fraught with. All this makes the study of this interesting and relevant!

Space dust

particles of matter in interstellar and interplanetary space. Light-absorbing condensations of the K. p. are visible as dark spots in the photographs. Milky Way. Weakening of light due to the influence of K. p. interstellar absorption, or extinction, is not the same for electromagnetic waves different lengths λ , resulting in reddening of the stars. In the visible region, extinction is approximately proportional to λ-1, while in the near ultraviolet region it almost does not depend on the wavelength, but there is an additional absorption maximum near 1400 Å. Much of the extinction is due to the scattering of light rather than its absorption. This follows from observations of reflective nebulae that contain condensate fields and are visible around B-type stars and some other stars bright enough to illuminate the dust. A comparison of the brightness of the nebulae and the stars illuminating them shows that the dust albedo is high. The observed extinction and albedo lead to the conclusion that the C. p. consists of dielectric particles with an admixture of metals with a size slightly less than 1 µm. The ultraviolet extinction maximum can be explained by the fact that inside the dust grains there are graphite flakes about 0.05 × 0.05 × 0.01 µm. Due to the diffraction of light by a particle whose dimensions are comparable to the wavelength, the light scatters predominantly forward. Interstellar absorption often leads to light polarization, which is explained by the anisotropy of the properties of dust grains (the prolate shape of dielectric particles or the anisotropy of graphite conductivity) and their ordered orientation in space. The latter is explained by the action of a weak interstellar field, which orients dust grains with their long axis perpendicular to field line. Thus, observing the polarized light of distant heavenly bodies, one can judge the orientation of the field in interstellar space.

The relative amount of dust is determined from the value of the average absorption of light in the plane of the Galaxy - from 0.5 to several magnitudes per kiloparsec in the visual region of the spectrum. The mass of dust is about 1% of the mass of interstellar matter. Dust, like gas, is distributed inhomogeneously, forming clouds and denser formations - Globules. In globules, dust is a cooling factor, screening the light of stars and emitting in the infrared range the energy received by the dust grain from inelastic collisions with gas atoms. On the surface of dust, atoms combine into molecules: dust is a catalyst.

S. B. Pikelner.

Big soviet encyclopedia. - M.: Soviet Encyclopedia. 1969-1978 .

See what "Space dust" is in other dictionaries:

Particles of condensed matter in interstellar and interplanetary space. According to modern concepts, cosmic dust consists of particles approx. 1 µm with graphite or silicate core. In the galaxy, cosmic dust forms ... ... Big Encyclopedic Dictionary

SPACE DUST, very fine particles solid, located in any part of the Universe, including meteorite dust and interstellar matter that can absorb starlight and form dark nebulae in galaxies. Spherical… … Scientific and technical encyclopedic dictionary

SPACE DUST- meteor dust, as well as the smallest particles of matter that form dust and other nebulae in interstellar space ... Great Polytechnic Encyclopedia

space dust- Very small particles of solid matter present in world space and falling to Earth... Geography Dictionary

Particles of condensed matter in interstellar and interplanetary space. According to modern ideas, cosmic dust consists of particles about 1 micron in size with a core of graphite or silicate. In the galaxy, cosmic dust forms ... ... encyclopedic Dictionary

Formed in space by particles ranging in size from a few molecules to 0.1 mm. 40 kilotons of cosmic dust settles on planet Earth every year. Cosmic dust can also be distinguished by its astronomical position, for example: intergalactic dust, ... ... Wikipedia

space dust- kosminės dulkės statusas T sritis fizika atitikmenys: engl. cosmic dust; interstellar dust; space dust vok. interstellarer Staub, m; kosmische Staubteilchen, m rus. cosmic dust, f; interstellar dust, f pranc. poussière cosmique, f; poussière… … Fizikos terminų žodynas

space dust- kosminės dulkės statusas T sritis ekologija ir aplinkotyra apibrėžtis Atmosferoje susidarančios meteorinės dulkės. atitikmenys: engl. space dust vok. kosmischer Staub, m rus. cosmic dust, f ... Ekologijos terminų aiskinamasis žodynas

Particles condensed in va in interstellar and interplanetary space. According to modern to representations, K. the item consists of particles in the size apprx. 1 µm with graphite or silicate core. In the Galaxy, cosmic rays form clusters of clouds and globules. Summons… … Natural science. encyclopedic Dictionary

Particles of condensed matter in interstellar and interplanetary space. Composed of particles about 1 micron in size with a core of graphite or silicate, it forms clouds in the Galaxy that cause the light emitted by stars to weaken and ... ... Astronomical dictionary

Books

• 99 secrets of astronomy, Serdtseva N. 99 secrets of astronomy are hidden in this book. Open it and learn about how the Universe works, what cosmic dust is made of and where black holes come from. . Funny and simple lyrics...

There are billions of stars and planets in the universe. And if a star is a flaming sphere of gas, then planets like Earth are made up of solid elements. Planets form in clouds of dust that swirl around a newly formed star. In turn, the grains of this dust are composed of elements such as carbon, silicon, oxygen, iron and magnesium. But where do cosmic dust particles come from? A new study from the Niels Bohr Institute in Copenhagen shows that not only can dust grains form in giant supernova explosions, they can also survive the subsequent shock waves of various explosions that impact the dust.

Computer generated image of how cosmic dust is formed in supernova explosions. Source: ESO/M. Kornmesser

How cosmic dust was formed has long been a mystery to astronomers. The dust elements themselves are formed in the glowing hydrogen gas in stars. Hydrogen atoms combine with each other to form heavier and heavier elements. As a result, the star begins to emit radiation in the form of light. When all the hydrogen is exhausted and it is no longer possible to extract energy, the star dies, and its shell flies into space, which forms various nebulae in which young stars can again be born. Heavy elements are formed primarily in supernovae, the progenitors of which are massive stars that die in a giant explosion. But how single elements stick together to form cosmic dust has remained a mystery.

“The problem was that even if the dust was formed along with the elements in supernova explosions, the event itself is so strong that these small grains simply should not have survived. But cosmic dust exists, and its particles can be of completely different sizes. Our study sheds light on this problem,” says Professor Jens Hjort, head of the Center for Dark Cosmology at the Niels Bohr Institute.

snapshot Hubble telescope unusual dwarf galaxy in which the bright supernova SN 2010jl originated. The image was taken before its appearance, so the arrow shows its progenitor star. The exploding star was very massive, approximately 40 solar masses. Source: ESO

In cosmic dust studies, scientists observe supernovae using the X-shooter astronomical instrument at the Very Large Telescope (VLT) complex in Chile. It has amazing sensitivity, and the three spectrographs included in it. can observe the entire light spectrum at once, from ultraviolet and visible to infrared. Hjort explains that at first they were expecting a "proper" supernova explosion. And that's when it happened, the surveillance campaign began. The observed star was extraordinarily bright, 10 times brighter than a typical average supernova, and its mass was 40 times that of the Sun. In total, the observation of the star took the researchers two and a half years.

“Dust absorbs light, and using our data, we were able to calculate a function that could tell us about the amount of dust, its composition and grain size. In the results, we found something really exciting,” Christa Gol.

The first step in the formation of cosmic dust is a mini explosion in which a star ejects material containing hydrogen, helium and carbon into space. This gas cloud becomes a kind of shell around the star. A few more of these flashes and the shell becomes denser. Finally, the star explodes, and a dense gas cloud completely envelops its core.

“When a star explodes, the shock wave collides with a dense gas cloud like a brick hitting a concrete wall. All this happens in the gas phase at incredible temperatures. But the place where the explosion hit becomes dense and cools down to 2000 degrees Celsius. At this temperature and density, the elements can nucleate and form solid particles. We found dust grains as small as one micron, which is a very large value for these elements. At that size, they should be able to survive their future journey through the galaxy.”

Thus, scientists believe that they have found the answer to the question of how cosmic dust is formed and lives.