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 deserts and meteorite craters. The size of this substance is less than 200 nm, which makes its study problematic.
Typically, the concept of cosmic dust includes a distinction between interstellar and interplanetary varieties. However, all this is very conditional. Most convenient option To study such a phenomenon, it is considered the study of dust from space on the borders of the Solar system or beyond.
The reason for this problematic approach to studying the object is that the properties of extraterrestrial dust change dramatically when it is near a star such as the Sun.
Theories of the origin of cosmic dust
Streams of cosmic dust constantly attack the Earth's surface. The question arises where this substance comes from. Its origins give rise to much debate among experts in the field.
The following theories of the formation of cosmic dust are distinguished:
- Decay of celestial bodies. Some scientists believe that cosmic dust is nothing more than the result of the destruction of asteroids, comets and meteorites.
- Remnants of a protoplanetary type cloud. There is a version according to which cosmic dust is classified as microparticles of a protoplanetary cloud. However, this assumption raises some doubts due to the fragility of the finely dispersed substance.
- The result of an explosion on the stars. As a result of this process, according to some experts, a powerful release of energy and gas occurs, 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 emergence of dust.
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.
Let's consider seven groups of cosmic dust in the atmosphere, different in external indicators:
- Gray debris irregular shape. These are residual phenomena after the collision of meteorites, comets and asteroids no larger than 100-200 nm in size.
- Particles of slag-like and ash-like formation. Such objects are difficult to identify solely by external signs, because they underwent changes after passing through the Earth's atmosphere.
- Grains round shape, which is similar in parameters to black sand. Outwardly, they resemble magnetite powder (magnetic iron ore).
- Small black circles with a characteristic shine. Their diameter does not exceed 20 nm, which makes studying them a painstaking task.
- 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.
- 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.
- Balls of heterogeneous structure made of glass and metal. Such elements are characterized by microscopic sizes within 20 nm.
- Dust found in intergalactic space. This type can distort the dimensions of distances during certain calculations and is capable of changing 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 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 along the orbital path of the star itself, reflecting its light and creating a nebula.
- Metal band. Representatives of this subspecies have specific gravity more than five grams per cubic centimeter, and their base consists mainly of iron.
- Silicate-based group. The basis - clear glass with a specific gravity of approximately three grams per cubic centimeter.
- Mixed group. The very name of this association indicates the presence of both glass and iron microparticles in the structure. The base also includes magnetic elements.
- Spherules with hollow filling. This species is often found in meteorite crash sites.
- Spherules of metallic formation. This subspecies has a core of cobalt and nickel, as well as a shell that has oxidized.
- Balls of homogeneous build. Such grains have an oxidized shell.
- Balls with a silicate base. The presence of gas inclusions gives them the appearance of ordinary slag, and sometimes foam.
It should be remembered that these classifications are very arbitrary, but serve as a certain guideline for designating the types of dust from space.
Composition and characteristics of cosmic dust components
Let's take a closer look at what cosmic dust consists of. There is a certain problem in determining the composition of these microparticles. Unlike gaseous substances, solids have a continuous spectrum with relatively few bands that are blurred. As a result, the identification of cosmic dust grains becomes difficult.
The composition of cosmic dust can be considered using the example of the main models of this substance. These include the following subspecies:
- Ice particles whose structure includes a core with a refractory characteristic. The shell of such a model consists of light elements. Large particles contain atoms with magnetic elements.
- The MRN model, the composition of which is determined by the presence of silicate and graphite inclusions.
- Oxide cosmic dust, which is based on diatomic oxides of magnesium, iron, calcium and silicon.
- Balls with metallic nature of formation. The composition of such microparticles includes an element such as nickel.
- Metal balls with the presence of iron and the absence of nickel.
- Silicone based circles.
- Iron-nickel balls of irregular shape.
The soils are fertile for the presence of cosmic material. Especially a large number of spherules were discovered in places where meteorites fell. The basis for them was nickel and iron, as well as various minerals such as troilite, cohenite, steatite and other components.
Glaciers also melt aliens from outer space in the form of dust in their blocks. Silicate, iron and nickel serve as the basis for the spherules found. All mined particles were classified into 10 clearly defined groups.
Difficulties in determining the composition of the object under study 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 gives great opportunities in terms of further activities in this direction. At a certain altitude, with the help of rockets, they discovered a specific belt consisting of cosmic dust. This gives grounds to assert that such extraterrestrial matter affects some processes occurring on planet Earth.
The influence of cosmic dust on the upper atmosphere
Recent studies indicate that the amount of cosmic dust can influence changes in upper layers atmosphere. This process is very significant because it leads to certain fluctuations in the climatic characteristics of planet Earth.
A huge amount of dust resulting from asteroid collisions fills the space around our planet. Its quantity reaches almost 200 tons per day, which, according to scientists, cannot but leave its consequences.
The northern hemisphere, whose climate is prone to cold temperatures and dampness, is most susceptible to this attack, according to the same experts.
The impact of cosmic dust on cloud formation and climate change has not yet been sufficiently studied. New research in this area raises more and more questions, the answers to which have not yet been obtained.
The influence of dust from space on the transformation of oceanic silt
Irradiation of cosmic dust by the solar wind causes these particles to fall to Earth. Statistics show that the lightest of the three isotopes of helium enters ocean silt in huge quantities through dust grains from space.
The absorption of elements from outer 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.
The influence of cosmic dust on the composition of the water of the World Ocean
If we look at the glaciers of Antarctica, they are striking in the number of meteorite remains found in them and the presence of cosmic dust, which is a hundred times higher than the normal background.
The excessively increased concentration of the same helium-3, valuable metals in the form of cobalt, platinum and nickel allows us to confidently assert the fact of the interference 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 ocean waters, which in itself is a unique phenomenon.
According to some scientists, the amount of cosmic dust in such peculiar ice sheets over the last million years amounts to about 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 cosmic dust:
This cosmic neoplasm and its influence on some factors of life on our planet have not yet been studied enough. It is important to remember that the substance can influence climate change, the structure of the ocean floor and the concentration of certain substances in the waters of the World Ocean. Photos of cosmic dust indicate how many more mysteries these microparticles conceal. All this makes studying this interesting and relevant!
Space exploration (meteor)dust on the surface of the Earth:problem overview
A.P.Boyarkina, L.M. Gindilis
Cosmic dust as an astronomical factor
Space dust refers to particles solid ranging in size from fractions of a micron to several microns. Dust matter is one of the important components of outer space. It fills interstellar, interplanetary and near-Earth space, penetrates the upper layers of the Earth's atmosphere and falls on the Earth's surface in the form of so-called meteor dust, being one of the forms of material (material and energy) exchange in the Space-Earth system. At the same time, it influences a number of processes occurring on Earth.
Dust matter in interstellar space
The interstellar medium consists of gas and dust mixed in a ratio of 100:1 (by mass), i.e. the mass of dust is 1% of the mass of the gas. The average gas density is 1 hydrogen atom per cubic centimeter or 10 -24 g/cm 3 . The density of dust is correspondingly 100 times less. Despite such an insignificant density, dust matter has a significant impact on the processes occurring in Space. First of all, interstellar dust absorbs light, which is why distant objects located near the galactic plane (where the dust concentration is greatest) are not visible in the optical region. For example, the center of our Galaxy is observed only in the infrared, radio and X-rays. And other galaxies can be observed in the optical range if they are located far from the galactic plane, at high galactic latitudes. The absorption of light by dust leads to distortion of distances to stars determined photometrically. Taking absorption into account is one of the most important problems in observational astronomy. When interacting with dust, the spectral composition and polarization of light changes.
Gas and dust in the galactic disk are distributed unevenly, forming separate gas and dust clouds; the concentration of dust in them is approximately 100 times higher than in the intercloud medium. Dense gas and dust clouds do not transmit the light of the stars behind them. Therefore, they appear as dark areas in the sky, which are called dark nebulae. An example is the Coalsack region in the Milky Way or the Horsehead Nebula in the constellation Orion. If near a gas and dust cloud there are bright stars, then due to the scattering of light on dust particles, such clouds glow, they are called reflection nebulae. An example is the reflection nebula in the Pleiades cluster. The most dense are clouds of molecular hydrogen H 2, their density is 10 4 -10 5 times higher than in clouds of atomic hydrogen. Accordingly, the density of dust is just as many times higher. In addition to hydrogen, molecular clouds contain dozens of other molecules. Dust particles are nuclei of condensation of molecules; on their surface, chemical reactions with the formation of new, more complex molecules. Molecular clouds are regions of intense star formation.
In composition, interstellar particles consist of a refractory core (silicates, graphite, silicon carbide, iron) and a shell of volatile elements (H, H 2, O, OH, H 2 O). There are also very small silicate and graphite particles (without a shell) of the order of hundredths of a micron in size. According to the hypothesis of F. Hoyle and C. Wickramasing, a significant proportion of interstellar dust, up to 80%, consists of bacteria.
The interstellar medium is continuously replenished due to the influx of matter during the shedding of stellar shells in the later stages of their evolution (especially during supernova explosions). On the other hand, it itself is the source of the formation of stars and planetary systems.
Dust matter in interplanetary and near-Earth space
Interplanetary dust is formed mainly during the decay of periodic comets, as well as during the crushing of asteroids. Dust formation occurs continuously, and the process of dust grains falling onto the Sun under the influence of radiation braking also continues continuously. As a result, a constantly renewed dust environment is formed, filling interplanetary space and being in a state of dynamic equilibrium. Its density, although higher than in interstellar space, is still very small: 10 -23 -10 -21 g/cm 3 . However, it noticeably scatters sunlight. When it is scattered on particles of interplanetary dust, optical phenomena such as zodiacal light, the Fraunhofer component of the solar corona, the zodiacal band, and counter-radiance arise. The zodiacal component of the glow of the night sky is also determined by the scattering of dust particles.
Dust matter in the Solar System is highly concentrated towards the ecliptic. In the ecliptic plane, its density decreases approximately in proportion to the distance from the Sun. Near the Earth, as well as near others major planets The concentration of dust increases under the influence of their attraction. Interplanetary dust particles move around the Sun in shrinking (due to radiation braking) elliptical orbits. Their speed of movement is several tens of kilometers per second. When colliding with solid bodies, including spacecraft, they cause noticeable surface erosion.
Colliding with the Earth and burning up in its atmosphere at an altitude of about 100 km, cosmic particles cause the well-known phenomenon of meteors (or “shooting stars”). On this basis, they were called meteoric particles, and the entire complex of interplanetary dust is often called meteoric matter or meteoric dust. Most meteor particles are loose bodies of cometary origin. Among them, two groups of particles are distinguished: porous particles with a density of 0.1 to 1 g/cm 3 and so-called dust lumps or fluffy flakes, reminiscent of snowflakes with a density of less than 0.1 g/cm 3 . In addition, denser asteroid-type particles with a density of more than 1 g/cm 3 are less common. At high altitudes, loose meteors predominate; at altitudes below 70 km, asteroid particles with an average density of 3.5 g/cm 3 prevail.
As a result of the fragmentation of loose meteoroids of cometary origin at altitudes of 100-400 km from the Earth's surface, a fairly dense dust shell is formed, the dust concentration in which is tens of thousands of times higher than in interplanetary space. The scattering of sunlight in this shell causes the twilight glow of the sky when the sun dips below the horizon below 100º.
The largest and smallest meteoroids of the asteroid type reach the Earth's surface. The first (meteorites) reach the surface due to the fact that they do not have time to completely collapse and burn when flying through the atmosphere; the latter - due to the fact that their interaction with the atmosphere, due to their insignificant mass (at a sufficiently high density), occurs without noticeable destruction.
The fall of cosmic dust onto the Earth's surface
While meteorites have long been in the field of view of science, cosmic dust has not attracted the attention of scientists for a long time.
The concept of cosmic (meteor) dust was introduced into science in the second half of the 19th century, when the famous Dutch polar explorer A.E. Nordenskjöld discovered dust of supposed cosmic origin on the surface of ice. Around the same time, in the mid-1970s, Murray (I. Murray) described rounded magnetite particles found in deep-sea sediments of the Pacific Ocean, the origin of which was also associated with cosmic dust. However, these assumptions were not confirmed for a long time, remaining within the framework of the hypothesis. At the same time, the scientific study of cosmic dust progressed extremely slowly, as pointed out by Academician V.I. Vernadsky in 1941.
He first drew attention to the problem of cosmic dust in 1908 and then returned to it in 1932 and 1941. In the work “On the Study of Cosmic Dust” V.I. Vernadsky wrote: “... The earth is connected with cosmic bodies and with outer space not only by exchange different forms energy. It is closely connected with them materially... Among the material bodies falling onto our planet from outer space, predominantly meteorites and cosmic dust, which is usually included in them, are accessible to our direct study... Meteorites - and at least to some extent the fireballs associated with them - are always unexpected for us in their manifestation... Cosmic dust is a different matter: everything indicates that it falls continuously, and perhaps this continuity of fall exists at every point of the biosphere, distributed evenly over the entire planet. It is surprising that this phenomenon, one might say, has not been studied at all and completely disappears from scientific records.» .
Considering the largest known meteorites in this article, V.I. Vernadsky Special attention pays attention to the Tunguska meteorite, the search for which was carried out by L.A. under his direct supervision. Sandpiper. Large fragments of the meteorite were not found, and in connection with this V.I. Vernadsky makes the assumption that he “... is a new phenomenon in the annals of science - the penetration into the region of earth's gravity not of a meteorite, but of a huge cloud or clouds of cosmic dust moving at cosmic speed» .
To the same topic V.I. Vernadsky returned in February 1941 in his report “On the need to organize scientific work on cosmic dust” at a meeting of the Committee on Meteorites of the USSR Academy of Sciences. In this document, along with theoretical reflections on the origin and role of cosmic dust in geology and especially in the geochemistry of the Earth, he substantiates in detail the program for searching and collecting material from cosmic dust that has fallen on the surface of the Earth, with the help of which, he believes, a number of problems can be solved scientific cosmogony about quality composition and “the dominant importance of cosmic dust in the structure of the Universe.” It is necessary to study cosmic dust and take it into account as a source of cosmic energy, continuously brought to us from the surrounding space. The mass of cosmic dust, noted V.I. Vernadsky, has atomic and other nuclear energy, which is not indifferent in its existence in Space and in its manifestation on our planet. To understand the role of cosmic dust, he emphasized, it is necessary to have sufficient material for its study. Organizing the collection of cosmic dust and scientific research of the collected material is the first task facing scientists. Promising for this purpose are V.I. Vernadsky considers snow and glacial natural plates of high-mountain and arctic regions remote from human industrial activity.
Great Patriotic War and death of V.I. Vernadsky, prevented the implementation of this program. However, it became relevant in the second half of the twentieth century and contributed to the intensification of research into meteoric dust in our country.
In 1946, on the initiative of Academician V.G. Fesenkov organized an expedition to the mountains of the Trans-Ili Ala-Tau (Northern Tien Shan), the task of which was to study solid particles with magnetic properties in snow deposits. The snow sampling site was chosen on the left side moraine of the Tuyuk-Su glacier (altitude 3500 m); most of the ridges surrounding the moraine were covered with snow, which reduced the possibility of contamination by earthly dust. It was also removed from sources of dust associated with human activity, and was surrounded on all sides by mountains.
The method for collecting cosmic dust in the snow cover was as follows. From a strip 0.5 m wide to a depth of 0.75 m, snow was collected with a wooden shovel, transferred and melted into aluminum cookware, poured into a glass container, where a solid fraction precipitated within 5 hours. Then top part the water was drained, a new batch of melted snow was added, etc. As a result, 85 buckets of snow were melted with a total area of 1.5 m2 and a volume of 1.1 m3. The resulting sediment was transferred to the laboratory of the Institute of Astronomy and Physics of the Academy of Sciences of the Kazakh SSR, where the water was evaporated and subjected to further analysis. However, since these studies did not give a definite result, N.B. Divari came to the conclusion that it would be better to use either very old compacted firns or open glaciers to take snow samples in this case.
Significant progress in the study of cosmic meteor dust came in the middle of the twentieth century, when, in connection with the launches of artificial Earth satellites, direct methods for studying meteor particles were developed - their direct registration by the number of collisions with a spacecraft or various types traps (installed on satellites and geophysical rockets launched to an altitude of several hundred kilometers). Analysis of the obtained materials made it possible, in particular, to detect the presence of a dust shell around the Earth at altitudes from 100 to 300 km above the surface (as discussed above).
Along with studying dust using spacecraft Particles were studied in the lower atmosphere and various natural reservoirs: in high mountain snow, in the Antarctic ice sheet, in the polar ice of the Arctic, in peat deposits and deep sea silt. The latter are observed mainly in the form of so-called “magnetic balls,” that is, dense spherical particles with magnetic properties. The size of these particles is from 1 to 300 microns, weight from 10 -11 to 10 -6 g.
Another direction is related to the study of astrophysical and geophysical phenomena associated with cosmic dust; this includes various optical phenomena: the glow of the night sky, noctilucent clouds, zodiacal light, counter-radiance, etc. Their study also allows one to obtain important data about cosmic dust. Meteor research was included in the program of the International Geophysical Year 1957-1959 and 1964-1965.
As a result of these works, estimates of the total influx of cosmic dust onto the Earth's surface were refined. According to T.N. Nazarova, I.S. Astapovich and V.V. Fedynsky, the total influx of cosmic dust to Earth reaches up to 10 7 tons/year. According to A.N. Simonenko and B.Yu. Levin (according to data for 1972), the influx of cosmic dust to the surface of the Earth is 10 2 -10 9 t/year, according to other, more recent studies - 10 7 -10 8 t/year.
Research into meteor dust collection continued. At the suggestion of Academician A.P. Vinogradov, during the 14th Antarctic expedition (1968-1969), work was carried out to identify patterns of spatiotemporal distributions of extraterrestrial matter deposition in the Antarctic ice sheet. The surface layer of snow cover was studied in the areas of Molodezhnaya, Mirny, Vostok stations and in a section of about 1400 km between Mirny and Vostok stations. Snow sampling was carried out from pits 2-5 m deep at points remote from polar stations. The samples were packed in plastic bags or special plastic containers. IN inpatient conditions samples were melted in glass or aluminum containers. The resulting water was filtered using a collapsible funnel through membrane filters (pore size 0.7 μm). The filters were moistened with glycerol and the number of microparticles was determined in transmitted light at a magnification of 350X.
We also studied polar ice, bottom sediments of the Pacific Ocean, sedimentary rocks, salt deposits. At the same time, the search for melted microscopic spherical particles, which are quite easily identified among other dust fractions, has proven to be a promising direction.
In 1962, the Commission on Meteorites and Cosmic Dust was created at the Siberian Branch of the USSR Academy of Sciences, headed by Academician V.S. Sobolev, which existed until 1990 and whose creation was initiated by the problem of the Tunguska meteorite. Work on the study of cosmic dust was carried out under the leadership of Academician of the Russian Academy of Medical Sciences N.V. Vasilyeva.
When assessing cosmic dust fallout, along with other natural tablets, we used peat composed of brown sphagnum moss according to the method of Tomsk scientist Yu.A. Lvov. This moss is quite widespread in the middle zone globe, receives mineral nutrition only from the atmosphere and has the ability to preserve it in the layer that was superficial when dust hit it. Layer-by-layer stratification and dating of peat allows us to give a retrospective assessment of its loss. Both spherical particles with a size of 7-100 microns and the microelement composition of the peat substrate were studied - a function of the dust it contained.
The method for isolating cosmic dust from peat is as follows. In an area of raised sphagnum bog, a site with a flat surface and a peat deposit composed of brown sphagnum moss (Sphagnum fuscum Klingr) is selected. Shrubs are cut from its surface at the level of the moss turf. A pit is laid to a depth of 60 cm, a platform is marked at its side the right size(for example, 10x10 cm), then a column of peat is exposed on two or three sides, cut into layers of 3 cm each, which are packed in plastic bags. The top 6 layers (noss) are considered together and can be used to determine age characteristics according to the method of E.Ya. Muldiyarov and E.D. Lapshina. Each layer is washed under laboratory conditions through a sieve with a mesh diameter of 250 microns for at least 5 minutes. The humus with mineral particles that has passed through the sieve is allowed to settle until the sediment completely falls out, then the sediment is poured into a Petri dish, where it is dried. Packed in tracing paper, the dry sample is convenient for transportation and for further study. Under appropriate conditions, the sample is ashed in a crucible and muffle furnace for an hour at a temperature of 500-600 degrees. The ash residue is weighed and subjected to either inspection under a binocular microscope at 56 times magnification to identify spherical particles measuring 7-100 microns or more, or subjected to other types of analysis. Because This moss receives mineral nutrition only from the atmosphere, then its ash component may be a function of the cosmic dust included in its composition.
Thus, studies in the area of the fall of the Tunguska meteorite, many hundreds of kilometers away from sources of technogenic pollution, made it possible to estimate the influx of spherical particles with a size of 7-100 microns or more onto the Earth’s surface. The upper layers of peat provided an opportunity to estimate global aerosol deposition during the study period; layers dating back to 1908 - substances of the Tunguska meteorite; lower (pre-industrial) layers - cosmic dust. The influx of cosmic microspherules onto the Earth's surface is estimated at (2-4)·10 3 t/year, and in general of cosmic dust - 1.5·10 9 t/year. Analytical methods of analysis, in particular neutron activation, were used to determine the trace element composition of cosmic dust. According to these data, the following falls annually onto the Earth's surface from outer space (t/year): iron (2·10 6), cobalt (150), scandium (250).
Of great interest in terms of the above studies are the works of E.M. Kolesnikova and her co-authors, who discovered isotopic anomalies in the peat of the area where the Tunguska meteorite fell, dating back to 1908 and speaking, on the one hand, in favor of the comet hypothesis of this phenomenon, on the other hand, shedding light on the cometary substance that fell on the surface of the Earth.
Most full review problems of the Tunguska meteorite, including its substance, for 2000 the monograph by V.A. Bronshten. The latest data on the substance of the Tunguska meteorite were reported and discussed at the International Conference “100 Years of the Tunguska Phenomenon”, Moscow, June 26-28, 2008. Despite the progress made in the study of cosmic dust, a number of problems still remain unresolved.
Sources of metascientific knowledge about cosmic dust
Along with the data received modern methods research, the information contained in extra-scientific sources is of great interest: “Letters of the Mahatmas”, the Teaching of Living Ethics, letters and works of E.I. Roerich (in particular, in her work “Study of Human Properties,” which provides an extensive program of scientific research for many years to come).
So in a letter from Koot Hoomi in 1882 to the editor of the influential English-language newspaper “Pioneer” A.P. Sinnett (the original letter is kept in the British Museum) provides the following data on cosmic dust:
- “High above our earth’s surface, the air is saturated and space is filled with magnetic and meteoric dust that does not even belong to our solar system”;
- “Snow, especially in our northern regions, is full of meteoric iron and magnetic particles, deposits of the latter are found even at the bottom of the oceans.” “Millions of such meteors and the finest particles reach us every year and every day”;
- “every atmospheric change on Earth and all perturbations occur from the combined magnetism” of two large “mass” - the Earth and meteoric dust;
There is "the terrestrial magnetic attraction of meteoric dust and the direct effect of the latter on sudden changes in temperature, especially in relation to heat and cold";
Because “our earth with all the other planets is rushing through space, it receives more of the cosmic dust on its northern hemisphere than on the southern”; “...this explains the quantitative predominance of continents in the northern hemisphere and the greater abundance of snow and dampness”;
- “The heat that the earth receives from the rays of the sun is, to the greatest extent, only a third, if not less, of the amount it receives directly from meteors”;
- “Powerful accumulations of meteoric matter” in interstellar space lead to a distortion of the observed intensity of starlight and, consequently, to a distortion of the distances to stars obtained by photometry.
A number of these provisions were ahead of the science of that time and were confirmed by subsequent research. Thus, studies of twilight atmospheric glow carried out in the 30-50s. XX century, showed that if at altitudes less than 100 km the glow is determined by the scattering of sunlight in a gaseous (air) medium, then at altitudes of more than 100 km the predominant role is played by scattering on dust particles. The first observations made with the help of artificial satellites led to the discovery of the dust shell of the Earth at altitudes of several hundred kilometers, as indicated in the mentioned letter from Kut Hoomi. Of particular interest are data on distortions of distances to stars obtained photometrically. Essentially, this was an indication of the presence of interstellar absorption, discovered in 1930 by Trempler, which is rightfully considered one of the most important astronomical discoveries 20th century. Taking into account interstellar absorption led to a reestimation of the astronomical distance scale and, as a consequence, to a change in the scale of the visible Universe.
Some provisions of this letter - about the influence of cosmic dust on processes in the atmosphere, in particular on the weather - have not yet found scientific confirmation. Further study is needed here.
Let us turn to another source of metascientific knowledge - the Teaching of Living Ethics, created by E.I. Roerich and N.K. Roerich in collaboration with the Himalayan Teachers - Mahatmas in the 20-30s of the twentieth century. The books of Living Ethics, originally published in Russian, have now been translated and published in many languages of the world. They pay great attention to scientific problems. In this case, we will be interested in everything related to cosmic dust.
The problem of cosmic dust, in particular its influx to the surface of the Earth, is given quite a lot of attention in the Teaching of Living Ethics.
"Pay attention to high places exposed to winds from snowy peaks. At the level of twenty-four thousand feet special deposits of meteoric dust can be observed" (1927-1929). “Aerolites are not studied enough, and even less attention is paid to cosmic dust on eternal snow and glaciers. Meanwhile, the Cosmic Ocean draws its rhythm on the peaks" (1930-1931). “Meteor dust is inaccessible to the eye, but produces very significant precipitation” (1932-1933). “In the purest place, the purest snow is saturated with earthly and cosmic dust - this is how space is filled even with rough observation” (1936).
Much attention is paid to issues of cosmic dust in the “Cosmological Records” of E.I. Roerich (1940). It should be borne in mind that E.I. Roerich closely followed the development of astronomy and was aware of its latest achievements; she critically assessed some theories of that time (20-30 years of the last century), for example in the field of cosmology, and her ideas have been confirmed in our time. The Teaching of Living Ethics and Cosmological Records of E.I. Roerich contain a number of provisions about those processes that are associated with the fall of cosmic dust on the surface of the Earth and which can be summarized as follows:
In addition to meteorites, material particles of cosmic dust constantly fall onto the Earth, which bring in cosmic matter that carries information about the Distant Worlds of outer space;
Cosmic dust changes the composition of soils, snow, natural waters and plants;
This especially applies to the locations of natural ores, which not only act as unique magnets that attract cosmic dust, but we should also expect some differentiation depending on the type of ore: “So iron and other metals attract meteors, especially when the ores are in their natural state and are not devoid of cosmic magnetism”;
Much attention is paid in the Teaching of Living Ethics mountain peaks, which according to E.I. Roerich “...are the greatest magnetic stations.” “...The Cosmic Ocean draws its rhythm on the peaks”;
Studying cosmic dust may lead to the discovery of new, not yet discovered modern science minerals, in particular metal, which has properties that help maintain vibrations with the distant worlds of outer space;
By studying cosmic dust, new types of microbes and bacteria may be discovered;
But what is especially important is that the Teaching of Living Ethics opens a new page scientific knowledge- the impact of cosmic dust on living organisms, including humans and their energy. It can have various effects on the human body and some processes on the physical and, especially, subtle planes.
This information is beginning to be confirmed in modern scientific research. Thus, in recent years, complex organic compounds have been discovered on cosmic dust particles, and some scientists have started talking about cosmic microbes. In this regard, the work on bacterial paleontology carried out at the Institute of Paleontology of the Russian Academy of Sciences is of particular interest. In these works, in addition to terrestrial rocks, meteorites were studied. It has been shown that microfossils found in meteorites represent traces of the vital activity of microorganisms, some of which are similar to cyanobacteria. In a number of studies, it was possible to experimentally demonstrate the positive effect of cosmic matter on plant growth and substantiate the possibility of its influence on the human body.
The authors of the Teaching of Living Ethics strongly recommend organizing constant monitoring of cosmic dust fallout. And use glacial and snow deposits in the mountains at an altitude of over 7 thousand meters as its natural reservoir. The Roerichs, living for many years in the Himalayas, dreamed of creating a scientific station there. In a letter dated October 13, 1930, E.I. Roerich writes: “The station must develop into a City of Knowledge. We wish in this City to give a synthesis of achievements, therefore all areas of science should subsequently be represented in it... The study of new cosmic rays, giving humanity new valuable energies, only possible at altitudes, for all the subtlest and most valuable and powerful lies in the purer layers of the atmosphere. Also, aren’t all the meteoric precipitation that settles on the snowy peaks and carries into the valleys worthy of attention? mountain streams?» .
Conclusion
The study of cosmic dust has now become an independent field of modern astrophysics and geophysics. This problem is especially relevant since meteoric dust is a source of cosmic matter and energy that is continuously brought to Earth from outer space and actively influences geochemical and geophysical processes, as well as having a unique effect on biological objects, including humans. These processes have not yet been studied much. In the study of cosmic dust, a number of provisions contained in the sources of metascientific knowledge have not been properly applied. Meteor dust manifests itself in terrestrial conditions not only as a phenomenon physical world, but also as matter carrying the energy of outer space, including worlds of other dimensions and other states of matter. Taking these provisions into account requires the development of a completely new method for studying meteoric dust. But the most important task remains the collection and analysis of cosmic dust in various natural reservoirs.
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Hello. In this lecture we will talk to you about dust. But not about the kind that accumulates in your rooms, but about cosmic dust. What is it?
Cosmic dust is very small particles of solid matter found anywhere in the Universe, including meteorite dust and interstellar matter that can absorb starlight and form dark nebulae in galaxies. Spherical dust particles about 0.05 mm in diameter are found in some marine sediments; it is believed that these are the remnants of the 5,000 tons of cosmic dust that fall on the globe every year.
Scientists believe that cosmic dust is formed not only from collisions and destruction of small solid bodies, but also due to the condensation of interstellar gas. Cosmic dust is distinguished by its origin: dust can be intergalactic, interstellar, interplanetary and circumplanetary (usually in a ring system).
Cosmic dust grains arise mainly in the slowly expiring atmospheres of stars - red dwarfs, as well as during explosive processes on stars and violent ejections of gas from the cores of galaxies. Other sources of cosmic dust include planetary and protostellar nebulae, stellar atmospheres, and interstellar clouds.
Entire clouds of cosmic dust, which are located in the layer of stars that form the Milky Way, prevent us from observing distant star clusters. A star cluster like the Pleiades is completely immersed in a dust cloud. The brightest stars in this cluster illuminate the dust like a lantern illuminates fog at night. Cosmic dust can only shine by reflected light.
Blue rays of light passing through cosmic dust are attenuated more than red rays, so the starlight that reaches us appears yellowish or even reddish. Entire regions of world space remain closed to observation precisely because of cosmic dust.
Interplanetary dust, at least in comparative proximity to the Earth, is fairly studied matter. Filling the entire space of the Solar System and concentrated in the plane of its equator, it was born largely as a result of random collisions of asteroids and the destruction of comets approaching the Sun. The composition of the dust, in fact, does not differ from the composition of meteorites falling on the Earth: it is very interesting to study it, and there are still many discoveries to be made in this area, but there seems to be no particular intrigue here. But thanks to this particular dust, in good weather in the west immediately after sunset or in the east before sunrise, you can admire a pale cone of light above the horizon. This is the so-called zodiacal light - sunlight scattered by small cosmic dust particles.
Interstellar dust is much more interesting. Its distinctive feature is the presence of a solid core and shell. The core appears to be composed mainly of carbon, silicon and metals. And the shell is mainly made of gaseous elements frozen onto the surface of the core, crystallized under the conditions of “deep freezing” of interstellar space, and this is about 10 kelvins, hydrogen and oxygen. However, there are impurities of molecules that are more complex. These are ammonia, methane and even polyatomic organic molecules that stick to a speck of dust or form on its surface during wanderings. Some of these substances, of course, fly away from its surface, for example, under the influence of ultraviolet radiation, but this process is reversible - some fly away, others freeze or are synthesized.
If a galaxy has formed, then where the dust comes from in it is, in principle, clear to scientists. Its most significant sources are novae and supernovae, which lose part of their mass, “dumping” the shell into the surrounding space. In addition, dust is also born in the expanding atmosphere of red giants, from where it is literally swept away by radiation pressure. In their cool, by the standards of stars, atmosphere (about 2.5 - 3 thousand kelvins) there are quite a lot of relatively complex molecules.
But here is a mystery that has not yet been solved. It has always been believed that dust is a product of the evolution of stars. In other words, stars must be born, exist for some time, grow old and, say, in the latest outbreak supernova produce dust. But what came first - the egg or the chicken? The first dust necessary for the birth of a star, or the first star, which for some reason was born without the help of dust, grew old, exploded, forming the very first dust.
What happened in the beginning? After all, when the Big Bang occurred 14 billion years ago, there were only hydrogen and helium in the Universe, no other elements! It was then that the first galaxies began to emerge from them, huge clouds, and in them the first stars, which had to go through a long life path. Thermonuclear reactions in the cores of stars should have “cooked” more complex chemical elements, turn hydrogen and helium into carbon, nitrogen, oxygen, and so on, and after that the star had to throw it all into space, exploding or gradually shedding its shell. This mass then had to cool, cool down and finally turn into dust. But already 2 billion years after big bang, in the earliest galaxies, there was dust! Using telescopes, it was discovered in galaxies 12 billion light years away from ours. At the same time, 2 billion years is too short a period for complete life cycle stars: during this time, most stars do not have time to grow old. Where the dust came from in the young Galaxy, if there should be nothing there except hydrogen and helium, is a mystery.
Looking at the time, the professor smiled slightly.
But you will try to solve this mystery at home. Let's write down the task.
Homework.
1. Try to guess what came first, the first star or the dust?
Additional task.
1. Report on any type of dust (interstellar, interplanetary, circumplanetary, intergalactic)
2. Essay. Imagine yourself as a scientist tasked with studying cosmic dust.
3. Pictures.
Homemade assignment for students:
1. Why is dust needed in space?
Additional task.
1. Report on any type of dust. Former students of the school remember the rules.
2. Essay. Disappearance of cosmic dust.
3. Pictures.
Hello!
Today we will talk about very most interesting topic, associated with such a science as astronomy! We're talking about cosmic dust. I assume that many people learned about it for the first time. So, I need to tell you everything that only I know about her! At school, astronomy was one of my favorite subjects, I will say more - my favorite, because it was in astronomy that I took the exam. Although I got the 13th ticket, which was the most difficult, I passed the exam perfectly and was satisfied!
If we can say in a completely understandable way what cosmic dust is, then we can imagine all the fragments that exist in the Universe from cosmic matter, for example, from asteroids. But the Universe is not only Space! Don’t be confused, my dears and good ones! The Universe is our entire world - our entire huge globe!
How is cosmic dust formed?
For example, cosmic dust can be formed when two asteroids collide in space and during the collision, the process of their destruction into small particles occurs. Many scientists are also inclined to believe that its formation is related to when interstellar gas condenses.
How does cosmic dust originate?
We have just found out how it is formed, now we are learning about how it arises. As a rule, these specks of dust simply appear in the atmospheres of red stars; if you have heard, such red stars are also called dwarf stars; arise when various explosions occur on stars; when gas is actively ejected from the galactic nuclei themselves; protostellar and planetary nebula- also contributes to its occurrence, however, like the stellar atmosphere itself and interstellar clouds.
What types of cosmic dust can be distinguished, given its origin?
As for the species specifically, regarding origin, we highlight the following types:
interstellar type of dust, when an explosion occurs on stars, there is a huge release of gas and a powerful release of energy
intergalactic,
interplanetary,
circumplanetary: appeared as “garbage”, remnants, after the formation of other planets.
Are there species that are classified not by origin, but by external characteristics?
black circles, small, shiny
circles are black, but larger in size, with a rough surface
circles balls black and white, which have a silicate base in their composition
circles that consist of glass and metal, they are heterogeneous and small (20 nm)
circles similar to magnetite powder, they are black and look like black sand
ash and slag-like circles
a species that was formed from the collision of asteroids, comets, meteorites
Good question! Of course it can. And from meteorite collisions too. Its formation is possible from the collision of any celestial bodies.
The issue of the formation and occurrence of cosmic dust is still controversial, and different scientists put forward their points of view, but you can adhere to one or two points of view on this issue that are close to you. For example, the one that is more understandable.
After all, even regarding its types there is no absolutely accurate classification!
balls, the base of which is homogeneous; their shell is oxidized;
balls, the base of which is silicate; since they have inclusions of gas, their appearance is often similar to slag or foam;
balls, the base of which is metal with a core of nickel and cobalt; the shell is also oxidized;
circles whose filling is hollow.
they can be icy, and their shell consists of light elements; Large ice particles even contain atoms that have magnetic properties,
circles with silicate and graphite inclusions,
circles consisting of oxides, the basis of which are diatomic oxides:
Cosmic dust has not been fully studied! There are a lot of open questions, because they are controversial, but I think we still have the basic ideas now!
COSMIC DUST, solid particles with characteristic sizes from about 0.001 microns to about 1 microns (and possibly up to 100 microns or more in the interplanetary medium and protoplanetary disks), found in almost all astronomical objects: from the Solar System to very distant galaxies and quasars . Dust characteristics (particle concentration, chemical composition, particle size, etc.) vary significantly from one object to another, even for objects of the same type. Cosmic dust scatters and absorbs incident radiation. Scattered radiation with the same wavelength as the incident radiation propagates in all directions. The radiation absorbed by the dust particle is transformed into thermal energy, and the particle usually emits in a longer wavelength region of the spectrum compared to the incident radiation. Both processes contribute to extinction - the weakening of the radiation of celestial bodies by dust located on the line of sight between the object and the observer.
Dust objects are studied in almost the entire range electromagnetic waves- from X-ray to millimeter. Electrical dipole radiation from rapidly rotating ultrafine particles appears to make some contribution to microwave emission at frequencies of 10-60 GHz. An important role is played by laboratory experiments in which they measure refractive indices, as well as absorption spectra and scattering matrices of particles - analogues of cosmic dust grains, simulate the processes of formation and growth of refractory dust grains in the atmospheres of stars and protoplanetary disks, study the formation of molecules and the evolution of volatile dust components in conditions similar to those existing in dark interstellar clouds.
Cosmic dust located in various physical conditions, are directly studied in the composition of meteorites that fell on the Earth’s surface, in the upper layers of the Earth’s atmosphere (interplanetary dust and the remains of small comets), during spacecraft flights to planets, asteroids and comets (circumstellar and cometary dust) and beyond the heliosphere (interstellar dust). Ground-based and space-based remote observations of cosmic dust cover solar system(interplanetary, circumplanetary and cometary dust, dust near the Sun), the interstellar medium of our Galaxy (interstellar, circumstellar and nebular dust) and other galaxies (extragalactic dust), as well as very distant objects (cosmological dust).
Cosmic dust particles mainly consist of carbonaceous substances (amorphous carbon, graphite) and magnesium-iron silicates (olivines, pyroxenes). They condense and grow in the atmospheres of stars of late spectral classes and in protoplanetary nebulae, and are then ejected into the interstellar medium by radiation pressure. In interstellar clouds, especially dense ones, refractory particles continue to grow as a result of the accretion of gas atoms, as well as when particles collide and stick together (coagulation). This leads to the appearance of shells of volatile substances (mainly ice) and to the formation of porous aggregate particles. The destruction of dust grains occurs as a result of sputtering in shock waves arising after supernova explosions, or evaporation during the process of star formation that began in the cloud. The remaining dust continues to evolve near the formed star and later manifests itself in the form of an interplanetary dust cloud or cometary nuclei. Paradoxically, around evolved (old) stars the dust is “fresh” (recently formed in their atmosphere), and around young stars the dust is old (evolved as part of the interstellar medium). It is believed that cosmological dust, possibly existing in distant galaxies, was condensed in the ejections of material from the explosions of massive supernovae.
Lit. look at Art. Interstellar dust.
