Satellites of asteroids in the solar system. Double asteroids
And at asteroids there is satellites?
Recently Acquired Image asteroid Ida from the automatic station "Galileo" made a strong impression on astronomers around the world. At asteroid small satellite ! But it turns out that this is not the first asteroid showing possession satellites .
According to David Dunham, President of the International Association of Occultation Observers, amateur astronomers have received some circumstantial evidence over the past 17 years for other large asteroids . Thus, observers from the California Institute of Technology, in addition to the main disappearance of a star, noted its secondary disappearances, which in most cases could be easily explained by the presence of small satellites asteroid. Most professional astronomers studying asteroids, were very skeptical about such assumptions and attributed such events to clouds, birds and other purely terrestrial phenomena. However, the observed "sharpness" of these events and their close coincidences in time with the main events convinced the observers themselves of the "celestial" nature of what was happening.
The first report of such a phenomenon was made back in 1977 after observing the coverage of a bright, visible to the eye, stars Gamma Centaur Heboe (6) March 5th of the same year. The second - a year later and concerned Herculina (532). In both cases, alleged drawings were published asteroids and them satellites . An entire chapter is devoted to these assumptions in The Book asteroids", published by the University of Arizona in 1979. But in 1987, the article" Lack of satellites asteroids ", published in Ikarus, cited the results of negative ground direct searches satellites asteroids . This could well have been due to the restlessness of the atmosphere, the weakness of the satellites and their proximity to a much brighter asteroid. Space radar observations and coverage records offered a much better chance. Moreover, over the past few years, the "contact-dual" structure of Castalia and Toutatis has been discovered by radar measurements.
Looks like there will be in the near future first artificial satellite asteroid . It is currently planned to launch in February 1999 satellite"NEAR" to the largest of those close to Earth asteroids - Eros (433). And if Eros has even one of his own satellite, then the mission NEAR becomes even more attractive. Now in the laboratory of applied physics of the University. Johns Hopkins (Laurel, USA) trajectory is being developed NEAR.
First photos (in green light) asteroid number 243 (Ida) and his satellite were obtained by a CCD camera on August 28, 1993, 14 minutes before the closest approach of the station to the asteroid up to a distance of 10,870 km. In total, several series of images were taken in 6 spectral bands.
Ida - an irregularly shaped block with a large number of impact craters on the surface and a maximum size of about 56 km - belongs to the main belt asteroids(i.e., those whose orbits lie between the orbits of Mars and Jupiter) and is 243 in a row since the discovery of the first asteroid in the early nineteenth century. She is part of the so-called Koronis family. Small satellite only 1.5 km in size has not yet received its name from astronomers and is so far registered as "1993 (243) 1", which means the year when the photograph was taken, the number of the asteroid and the fact that this is the first discovered moon of Ida.
Although it seems that satellite "hides" behind Ida, in fact he is slightly closer to " Galilee "than himself asteroid. Comparing the optical images with data from a near-IR sensitive mapping spectrometer on board the station, a team of researchers from the Jet Propulsion Laboratory determined that this satellite away from the center of Ida about 100 km. Sunlight falls on the right, and a deep shadow on the left is nothing but the night side of such a small "planet". The resolution of the image is about 100 m per pixel, and in this case, the existence of 2-3 impact craters, whose dimensions are about 1/7 of the entire surface, can be suspected satellite .
Unfortunately, due to the unexpectedness of the result for this flight, it was not possible to obtain any orbit parameters satellite nor even estimate the circulation period. Therefore, after some hesitation, it was decided to change the original program of the station "Galileo", which assumed only its launch into a near-Jupiterian orbit. After difficult maneuvers, the station returned to Ida and studied it from February to the end of June 1994.
Source:Astronet
Do asteroids have satellites? A recent image of the asteroid Ida from the automatic station Galileo made a strong impression on astronomers around the world. An asteroid has a small satellite!
The etymology of names, their days of celebration and heavenly patrons There is another interesting way to link your name and horoscope: for this you can use the names of asteroids, of which about five thousand have been discovered.
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Launched satellites "GLONASS" could not be put into orbit Due to an emergency situation navigation satellites "Glonass-M", most likely, could not be put into orbit, "Interfax" on Sunday, a source in the rocket and space industry.Telescopes Sky-Watcher in the astro-shop PLANETARIUM
TO THE QUESTION OF THE ORIGIN OF SATELLITES OF THE PLANETS AND ASTEROIDS.
In general, an interesting and informative article by N. Garkavy and Doctor of Physical and Mathematical Sciences V. Prokofieva-Mikhailovskaya "Double asteroids and the loneliness of the Moon" in the journal "Science and Life", 2015, No. 11, pp. 44-52) is not free from contradictions. Let's consider some of them.
“The moon was formed .. at a distance of 3-4 planetary radii (about 19,000 kilometers - A.M.) .. due to many .. weak collisions that threw part of the matter from the earth’s mantle into the protolunar disk .. and only then moved away to a distance at 60 radii of the Earth (384,400 kilometers - A.M.) ... The moon is still moving away from the Earth at a speed of 4 centimeters per year. (p. 52).
Neglecting the time required for the formation of the Moon according to this theory (at least several million years) and the fact of increasing the initial rate of removal of the Moon to the current 4 centimeters per year, assuming it to be constant, we obtain the maximum possible removal during the existence of the Earth (about 4.6 billion years) Moons at 184,000 kilometers (4,600,000,000 years x 0.00004 km). That is, at the time of its origin, the Moon was at a distance of 200,400 km from the Earth. \u003d 384 400 -184 000, which is 31-32 earth radii, and not 3-4 as the authors of the article believe. To remove the Moon by 56 Earth radii (358,400 kilometers) after its formation under the above conditions, it would take about 9 billion years, which is almost twice the generally recognized lifetime of the Earth.
These facts give rise to doubts about the realism of the multi-impact model of the formation of the Moon promoted by the authors, because the radius of the geostationary orbit, where the centrifugal force is balanced by the Earth's gravity, is only 35,786 kilometers.
I dare to propose a model that does not contradict the currently known facts of the almost simultaneous formation of the Earth and the Moon from one protoplanetary cloud with two accretion centers at a distance of about 200,000 kilometers from each other. If there is only one accretion center in a protoplanetary cloud, a planet is formed without a satellite. For example, Venus or Mercury. There may well be several accretion centers in protoplanetary clouds. Then, the planets formed from them will have, respectively, several satellites: Jupiter, for example, has four of them, and Pluto has five.
N. Garkavy and V. Prokofieva-Mikhailovskaya see and note the shortcomings of the mega-impact model for the formation of asteroid satellites: “.. the most important drawback of the mega-impact theory (the formation of satellites due to collisions of comparable masses / from 10 to 45% / A.M. cosmic bodies) in that it does not explain the appearance of many thousands of satellites around asteroids with weak gravity, unable to keep fragments of a strong impact near the central body. In addition, such a number of collisions of bodies comparable in mass is simply statistically unbelievable.” (p. 51).
But the multi-impact model, of which they are supporters, sins the same: “..the probability of the presence of a satellite steadily increases with an increase in the speed of rotation of the asteroid; it (probability - A.M.) is great for small and large asteroids and minimal for medium-sized asteroids” (p. 47). However, if satellites of asteroids are formed from the rocks of their surface layer, knocked out as a result of bombardment by micrometeorites, then at the same rotation speed, the possibility of holding bombardment fragments in their gravitational field is certainly higher for medium-sized asteroids than for small asteroids, and, therefore, should be greater. and the probability of occurrence of satellites; if the asteroid and its satellites are formed simultaneously from a single protoasteroid cloud, then the absence of a satellite or satellites for a particular medium-sized asteroid means that there is only one accretion center in the protoasteroid cloud.
The assertion that the multi-impact (multi-impact) model of the formation of asteroid satellites explains the mass loss of the asteroid belt is also highly controversial, because the mechanism of satellite formation described in the article illustrates only the redistribution of matter between asteroids and their satellites inside the asteroid belt. The authors themselves write that: “Satellites of asteroids are self-organizing structures that grow, feeding on dust flying away from asteroids. ... the emergence of numerous satellites of asteroids (to which this lost mass went) ”.
The model I proposed for the simultaneous formation of planets and their satellites from single protoplanetary clouds with several accretion centers, and asteroids and their satellites from single protoasteroid clouds also with several accretion centers, claims to be the main (most common) as the most consistent with the currently known facts , but does not exclude the fundamental possibility of the formation of satellites around planets and asteroids in some cases according to the multi-impact and mega-impact models.
11/16/2015 Alexander Malchukov.
Reviews
It is interesting to write about asteroids and satellites.
I'm more interested in their mineral composition. Many have a crystalline structure and are similar to terrestrial basalts, gabbro, diorites, but there are no granites in them. I saw sections of iron-nickel meteorites. They have a widmanstatt texture - almost perpendicularly intersecting strokes. This is a sign of a very long slow solidification of the initial melt (millions of years).
The conclusion to everything is that asteroids, meteorites are fragments of planets with an initial internal molten composition and with a long period of solidification and crystallization of minerals and rocks inside them. This conclusion is not new, the presence of Phaethon between Mars and Jupiter is assumed. Asteroid belts could have been picked up by the Sun from outer space as well.
How do you think - how could crystalline structures be formed in asteroids and meteorites?
After the big bang, if there was one, all matter was in a molten state and slowly (maybe millions of years) cooled down. Then the legend of Phaeton becomes superfluous.
Here you have a big mistake. After the Big Bang, there was no matter yet - only radiation in the form of energy quanta. Then, as it cools, the stage of formation of elementary particles from quanta began - electrons-positrons, protons-antiprotons, and then the stage of formation of atoms of matter - hydrogen and helium.
This allegedly took 1 billion years (according to Shklovsky and Ginzburg). And other atoms were formed much later - in the depths of stars and their subsequent explosion. It took several billion years.
So the substance in the Cosmos was nowhere in the melt - there the temperature is below zero - 150 degrees. The melt of mineral matter could only be in the bowels of planets with a diameter of at least 2000 km. There is a book - Small planets.
And what exploded if there was no substance? And what did all these quarks, cracklings, positrons, electrons come from? And the temperature in the space covered by the explosion was -273 degrees?
It was not the substance that exploded, but the "Singular Point of the Physical Vacuum" that lost stability - such is the hypothesis. The human mind cannot understand this.
That's right, when the "geniuses" do not know what to say, they invent "singular points", secretly laughing at the simpletons amazed by their genius.
"The Unified Theory of Matter by V.Ya. Bril".
In my opinion, this is a masterpiece of another nonsense of a person poorly educated in the natural sciences, trying to create "his own theory." This is evidenced by a hodgepodge of scientific terms with religion and esotericism: “kinetic (quantum) theory of gravity”, “unified theory of matter”, “fundamental strings”, “elementary particles”, soul, spirit, aura, “information field”, “world mind ”, “field form of life”. To save from such a dish, I propose a remedy from REAL science:
A BRIEF DETERMINER OF SCIENTIFIC QUARRATIVITY.
Book counters, periodicals, TV programs, Internet sites and forums are full of anti-scientific rubbish. Sincerely sympathizing with the victims of pseudoscience and charlatanism, let's try to make a short guide to "brechology", like the guides to dangerous animals and poisonous mushrooms.
FIRST ORDER FEATURES
If the publication contains the words: aura, biofield, chakra, bioenergetics, panacea, energy-informational, resonant-wave, psychic energy, thought-form, telegony, wave genetics, wave genome, supersensible, astral, then you can be sure that you are dealing with charlatan writing.
The list could go on, but it doesn't make much sense. The terminology of the charlatan brethren is expanding all the time, so orientation by "signal words" is not always sufficient for a correct assessment of the text.
SIGNS OF THE SECOND ORDER
This is information about the identity of the author. As a rule, the main specialty of the authors of pseudoscientific works is far from the areas of knowledge to which their opuses are devoted. I deliberately use the term "opus" (from the Latin opus - business), so as not to specify whether this is a book, an article or a TV show.
The scientific regalia of the author are of great interest for analysis. The more of them and the more carefully they are listed, the more carefully one should treat the text. For real scientists, vanity is considered bad manners.
"Honorary membership" in various academies is especially alarming because of the significant differences between a member and an honorary member.
Without a doubt, many truly outstanding people have received many awards. But, alas, their works are understandable only to the same professionals, and they almost never condescend to popular publications.
In the works of professionals, there is not only no self-praise, but also a general mention of the value of this work.
Expressions like: "Our research completely changes the idea of so-and-so"; "It has a special value"; "Everything that was before us is of no value" - coupled with promises of radical changes in science, immediate huge effect at negligible costs, with the humiliation of predecessors and competitors - are reliable symptoms of charlatanism.
The definition of the author of his work as revolutionary is a very serious reason to doubt both the competence of the author and the value of his creation.
SIGNS OF THE THIRD ORDER.
These signs are found, in fact, in the content of creation. Some of the points that pertain to this section have already been mentioned above. The authors of fantasy and charlatan writings are by no means interested in quickly identifying their anti-science. Some have achieved remarkable success in mimicry and are remarkably adept at disguising the pseudoscientific nature of their creations in the midst of perfectly reasonable reasoning. Limiting myself to medicine and biology, let me remind you that in biological systems and in living organisms, all known physical laws operate just as rigorously as in non-living ones. Specific biological laws are no less powerful and are also not violated. Therefore, if the author seriously talks about paranormal abilities - seeing through the wall, reading letters in closed envelopes, levitation, telekinesis, reviving the dead, operations without a knife (with the extraction of giblets, but without a wound and scar),
The use of pseudoscientific terminology is designed not so much for the mind of the reader, but for the hypnotizing effect of incomprehensible words that serve as a conductor of author's ideas in the brain of readers / listeners. The reader is simply not left time to comprehend the verbal flow. He only has time to grasp individual pieces written in normal language. They also contain the thoughts that, according to the author's intention, the consumer of the product of his philosophizing should assimilate. In theory, one should read thoughtfully, slowly ... But where there, we are accustomed (and forcedly accustomed) to speed reading. So we swallow without chewing. This method of absorbing spiritual food is more dangerous for the brain than hastily absorbing bodily food for the stomach.
So, an increased concentration of foreign language terms where it is quite possible to get by with the words of the native language, an abundance of complex grammatical structures
SIGNAL FOR THE READER: "Look, don't get in trouble!" Charlatan opuses are characterized by the absence of doubts and intolerance to objections. An undoubted sign of quackery is the lack of response to criticism on the merits and the transition to the personality of the opponent.
Pseudoscientific "inventions" are characterized by universality and universality. A charlatan does not stoop to solve narrow problems. If he made a revolution in science, then global. If he treats oncological diseases with an aspen stick (by God, there is such a patent!).
If he invented a miraculous diet, then it suits everyone, heals completely and without the right to appeal. If he describes a miraculous drug, then it has no contraindications and you can give it to anyone.
When an author lacks factual or logical (often both) arguments, he resorts to referring to authorities. At the same time, the late authorities are often credited with statements and views that were absolutely alien to them during their lifetime. A well-known case: the dead have no shame. In such cases, familiarity with the biography of the greats allows you to fairly reliably determine the forgery and treat the author's creation accordingly.
If the "revolutionary doctrine" offered to the consumer has no scientific background, this is a very, very reliable sign of Brechology. Science develops progressively, the basis for new knowledge is always the old, proven. If the author has no predecessors, and his "science" jumped out into the light of day, like a devil out of a snuffbox, it will be completely natural to treat it as an evil spirit. Similarly, I propose to treat all kinds of "insights", "influences" and other God's gifts. Any esotericism, hysteria and mysticism, by their very presence in a "scientific" opus, unequivocally determine its belonging to Brechology.
Another sign of the third order, I would call "Occam's unshaven". Occam's razor was the principle formulated back in the 14th century by the Franciscan monk William of Occam, which states: Entia non sunt multiplicanda sine necessitate - "Entities should not be multiplied without necessity." In other words, one should not invent a complex explanation where a simple one suffices. Einstein slightly changed the wording: "Everything should be simplified as long as possible, but no more." In pseudoscientific opuses, this principle is not respected.
An example of a violation of Occam's principle is the reasoning about the Bermuda Triangle. In an area with extremely intensive navigation, with very unstable air currents and sea currents, ships and aircraft disappear from time to time. Brechologists explain these catastrophes by the action of otherworldly forces. Accidents due to natural causes (loss of communication with the aircraft due to power failures; falling into the sea due to navigation errors and excessive fuel consumption; the death of a ship under the impact of an abnormally high solitary wave) are rejected in favor of beautiful and unsubstantiated fabrications.
A simple recommendation: use your common sense to distinguish between science and bullshit.
If the lotteries have not yet gone bankrupt, the prophets are worthless. If there are still sick people, all miraculous drugs are garbage. If someone offers a miracle - he is a charlatan.
Reference source: JOURNAL "SCIENCE AND LIFE" 2005.
God, how many bukoff and sloff!
I am absolutely not going to comment on Bril's theory from a scientific point of view, but there are no "auras" and other esotericism there at all, everything is scientific from a person who has been engaged in science all his life.
For some reason, you like bukffy and sloff Bril, but you don’t like real science? What would it be from?
They read Bril poorly - there are words there: soul, spirit, aura, “information field”, “world mind”, “field form of life”.
And you start talking about something you don't know. This is not good. Read again - have you read it for a long time?
I read it more than once, but for a long time. In any case, there the physical picture of the world is not presented through esotericism, and the hypothesis of "elementary strings" was discussed by physicists quite seriously thirty or forty years ago.
If there are words about "soul", "aura", etc., they do not define the main content of the text. I repeat, I do not have sufficient knowledge to discuss Brill's hypotheses from a scientific point of view, but one should definitely not drag esotericism here by the ears.
Modern scientific theories go through a stage of hypothesis with a long and repeated experimental verification by the scientific community. Only after practical confirmation do they move to the rank of theory. But even after that, they continue to be under experimental verification and elimination of inconsistencies.
And then immediately a theory based on postulates - that is, axioms from the head. The author of this "theory" at the end writes that it is not science that can test it, but only a higher mind. That is, he believes that his theory is above the human mind. Such fashionable "theories" are now filled with the Internet. Their collection is given on the site scorche.ru and there is also a critical analysis of specialists.
Since I regularly come across the fact that I am credited with what I supposedly believe, then in relation to others I try not to speculate what the author believed, especially when there is a reference to the "higher mind". With all the achievements that humanity has achieved, it seems to me that it sometimes suffers from a certain self-confidence.
I don’t want to blame anyone, but experts are sometimes in the grip of their knowledge and experience and are not always receptive to alternative views, because then they will have to admit their own delusions. Especially applies to the so-called. humanities. In principle, there is nothing new in this, it has always been so. Of course, as long as this or that theory is not supported by experimental material, it is not of particular interest. I repeat again that I am not speaking here in defense of Bril, but the same Einstein theory did not immediately receive experimental confirmation, and even then the opinion about it is still ambiguous, but more than a century has passed.
Over the past few decades, the LHC has been built to test some assumptions about the structure of matter, but although the discovery of the Higgs boson was announced, it was somehow vague, and the collider itself almost burned down, they have been repairing it for several years. But how many people are at work.
Here you have a more objective view of reality. It is difficult to be objective, especially without knowledge of the basics of the natural sciences. Humanitarians and journalists tend to believe in miracles. Even Mikhail Veller believes in Chumak's "wonderful abilities" - he invited him to his program. Weller says - "I know physics at the level of Peryshkin's school textbook", and he himself undertook to create an "energy-information theory". Do they have some kind of itching with these "creators" of the current ones?
The Higgs boson fit into the hypothesis quite confidently, even Higgs himself was pleased. Two competing groups of scientists (collaborations), using different search methods, came to a common opinion - the boson exists.
The power of the collider is gradually growing and new discoveries are possible ahead. The collider is better than fiction. But they will still appear - this is how the human mind works, the unknown weighs on him and he fills this void with fantasy - at best, with a hypothesis. Again a lot of sloff I wrote?
Here you can see the distrust of the sciences. Naturally, everyone has the right to doubt the discoveries and laws of science. One can doubt even Newton's laws. But our everyday doubts such as a conversation - "Science say? Something is unbelievable" cannot be compared with the doubts of a specialist. They are as different as heaven from earth.
Do you remember Chekhov's short story "Letter to a learned neighbor"? There, an inquisitive neighbor doubted whether there were spots on the Sun and proved their apparent absence as follows: "It cannot be, because it can never be."
The Higgs boson is not a theoretical fiction, but it was highlighted in the course of experiments as the "missing link" in the system of elementary particles. Higgs roughly described its characteristics based on the behavior of other particles. This is very similar to the discovery of Pluto - the "missing planet" of the solar system and it was discovered by predicted characteristics, that is, calculated.
The interpretation of scientific facts is again not an everyday matter, but a purely professional matter. The world community will never miss a hack, as it repeatedly checks any new facts. If there is an ambiguous interpretation, then he speaks openly about it and collects new experimental data.
Science for some 300 years has led mankind from a torch and a candle to electrification, telegraph, telephone, radio, electronics, computer, information revolution, space exploration. And all the same, there are critics of science and its homegrown debunkers - especially among believers and esotericists, who at the same time very willingly use the benefits of science and technology.
Such a contradictory human nature. Psychology Mystery?
To talk about distrust of science in relation to me is not entirely correct. I draw the conclusion to something else: it is impossible to fall into euphoria from the received scientific data and build far-reaching forecasts. Firstly, it has repeatedly happened that the experimental data were not given a completely correct or complete explanation, and secondly, one should not forget that each subsequent theory must include the previous one as a special case.
If we talk specifically about Newton's laws, then we can, for example, pay attention to the following nuance.
There is a "gravitational constant" (~6.67x...) in the Law of universal gravitation. At one time, many years of experiments were carried out in order to accurately calculate its value, but in the end we can only talk about a probabilistic characteristic. I fully admit that Newton's formula in the usual sense is valid only for relatively small masses, as mentioned by Bril (not the fact that it is so!).
By the way, it is interesting that for the interaction of electric charges the formula looks almost the same, only instead of the "gravitational constant" - "dielectric" (as applied to a specific medium).
In the Higgs boson, I am greatly confused by its declared mass, which is many times greater than even the mass of a proton. I'm surprised it wasn't opened earlier. In general, experiments on accelerators remind me of an attempt to find out, for example, how a house works, smashing it to smithereens and then building a picture from the wreckage.
Finally, there are many testimonies (especially regarding history) that do not fit into the usual ideas, but they try not to remember them so as not to confuse the minds.
(PS I am always annoyed by a long exchange of opinions in the margins of other people's reviews. While maintaining further interest in the dialogue, if you don't mind, I suggest continuing it on my pages or, even more conveniently, via regular e-mail.)
The daily audience of the Proza.ru portal is about 100 thousand visitors, who in total view more than half a million pages according to the traffic counter, which is located to the right of this text. Each column contains two numbers: the number of views and the number of visitors.
An asteroid satellite is an asteroid orbiting another asteroid. The satellite and the asteroid are a system supported by the gravity of both objects. An asteroid system in which the dimensions of the satellite are comparable to the size of an asteroid is called a double asteroid. To date, systems of three components are also known.
Until the end of the 19th century, asteroids were presented to scientists as single bodies. But at the beginning of the 20th century, with the improvement of observational equipment, there were assumptions about the existence of a duality of asteroids. The first studies were carried out, in particular, the asteroid (433) Eros was studied in detail. However, there were few such studies, and they contradicted conventional wisdom.
The first attempts to identify satellites around asteroids, using measurements of the attenuation of the brightness of stars when they are covered by asteroids, were carried out for objects (6) Hebe (1977) and (532) Herculinus (1978). In the course of the research, the presence of satellites at these objects was assumed, but these data were not confirmed. Later, the Czech astronomer Petr Pravec (1991) and the German G. Hahn (1994) drew attention to the variable brightness of two small asteroids passing near the Earth, which could indicate their duality. Unfortunately, these observations could not be repeated.
(243) Ida is a small main-belt asteroid in the Koronids family. It was discovered on September 29, 1884 by the Austrian astronomer Johann Palisa in the observatory of the city of Vienna (Austria) and named after a nymph in ancient Greek mythology. Later observations identified Ida as a class S stony asteroid (one of the most common spectral classes in the asteroid belt). |
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ASTEROID SATELLITES |
The first confirmed satellite of an asteroid was discovered in 1993 by the automatic interplanetary station Galileo. It was discovered near the asteroid (243) Ida, during the flight of the AMS near the object. The satellite was named Dactyl. The second discovered satellite in 1998 was the Little Prince, a satellite of the asteroid (45) Eugene. In 2002, the first satellite was discovered near the trans-Neptunian object 1998 WW31.
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Time-lapse of asteroid (45) Evgeniy and his satellite
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ASTEROID SATELLITES |
The discovery of satellites allows a better study of asteroids, since knowledge of satellite orbits is of great importance for obtaining fundamental physical parameters of a binary system, such as mass, and sheds light on its possible formation and evolution. Therefore, scientists are looking for various methods for studying asteroids, aimed at finding their satellites. Here is some of them:
- optic- direct optical observations using space and ground-based telescopes with adaptive optics;
The optical method is the most obvious, but it has a number of disadvantages, the most important of which is the difficulty of detecting a faint object next to a brighter one and the need to conduct observations with a high angular resolution. Therefore, optical observations make it possible to detect a small number of satellites with sufficient large sizes relative to the asteroid, and located at a considerable distance from it.
- radar- with the help of space and ground-based radio telescopes;
The radar method makes it possible to accurately measure the shape of an object (with an accuracy of up to 10 meters on the largest radio telescopes) by measuring the delay time of the reflected signal. The disadvantage of the radar method is the short range. As the distance to the object under study increases, the accuracy of the data decreases significantly.
- photometric- measurement of the decrease in the brightness of a star when it is covered by an asteroid;
The method of photometric observations of occultations of stars by asteroids uses measurements of the dimming of the occulted star. The essence of the method is to observe a star from a zone outside the calculated asteroid coverage band. The advantage is that such observations can be made using amateur astronomical instruments. The disadvantage is that the asteroid satellite must cover the observer's area at the time of the study.
- AMC span
AMS studies are the most accurate, as they allow using the equipment available at the station at close range.
Origin of satellites
The origin of asteroid satellites is currently not unequivocally determined. There are different theories. One of the widely accepted claims is that satellites may be the after-product of an asteroid's collision with another object. Other pairs could be formed by the capture of a small object by a larger one. The formation resulting from the collision is constrained by the angular momentum of the components. Binary asteroid systems with small distances between components are consistent with this theory. However, it is hardly suitable for remote components.
According to another hypothesis, the satellites of asteroids formed at the initial stage of the evolution of the solar system.
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Asteroid Sylvia with two satellites
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ASTEROID SATELLITES |
It is assumed that many asteroids consist of several stone blocks, weakly bound by gravity and covered with a layer of regolith, so a small external impact can lead to a break in such a system and the formation of satellites at a short distance.
General characteristics
The tidal effects of the asteroid on the satellite affect the parameters of its orbit and align the rotation axes of both objects with the axis of the main moment of inertia. The satellite itself eventually takes on a somewhat elongated shape under the influence of the gravitational field of the asteroid. If the period of rotation of the main body is less than the period of revolution of the satellite around it (which is typical for the solar system), then over time the satellite moves away, and the period of rotation of the main body slows down.
Double asteroids
A double asteroid is a system of two asteroids gravitationally bound to each other, revolving around a common center of mass, like a binary system of stars.
If the asteroids are approximately the same size, then the center of mass of such a system is located approximately in the middle, between the asteroids, a good example of such a system is the asteroid (90) Antiope. If the satellite is much smaller than the main asteroid, then the center of mass is located inside the larger asteroid, as is the case with the Earth-Moon system. Such systems include most of the known binary systems, such as the asteroids (22) Calliope, (45) Eugenia, (87) Sylvia, (107) Camilla, (121) Hermione, (130) Electra, (283) Emma, ( 379) Guenna.
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Artistic representation: (90) Antiope and S/2000 (90) 1
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ASTEROID SATELLITES |
Some impact craters, such as the Clearwater crater in Canada, could have been formed during the fall of binary asteroids.
Ways of formation of binary systems are not clear enough. Accidental capture of asteroids in the main belt as a result of a close flyby is practically impossible, since when a satellite is captured, it undergoes strong tidal braking, which, in accordance with the law of conservation of energy, is accompanied by a strong deformation of the satellite under the action of tidal forces, in which its kinetic energy is converted into heat . For large bodies, such a capture is quite acceptable, but in the case of bodies of small mass, such as most asteroids, it is unacceptable, because due to the enormous speed (more than ten km / s), the kinetic energy of motion of even a relatively small body is so large that due to for the small mass of the asteroid, its gravity is simply not enough to stop a relatively large body and transfer it to a stable orbit around itself.
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Artistic performance: 1998 WW31 and IAC S/2000 (1998 WW31) 1
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ASTEROID SATELLITES |
Several possible ways of forming binary asteroid systems are proposed. Binary systems of such asteroids as (22) Calliope, (45) Eugenia, and (87) Sylvia could have been formed by the destruction of the parent asteroid as a result of a collision with another asteroid. Trans-Neptunian binary systems could have been formed even during the formation of the solar system as a result of mutual capture. Due to their great distance from the Sun, their orbital velocities, and hence the kinetic energy of motion, are very small, which makes such a capture quite possible.
Such systems can also be formed as a result of a close approach to some large planet, for example, the Earth. At the same time, due to the action of internal stresses arising under the action of tidal forces, asteroids often break up into several fragments, which can then be combined into a multiple system or simply move together in close orbits.
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4 images of the Patroclus - Menetius system taken using adaptive optics at the Keck Observatory (2005) and the Gemini Observatory (2007) |
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ASTEROID SATELLITES |
According to another theory, the decay of asteroids can occur under the influence of the YORP effect, which consists in an increase in the speed of rotation of irregularly shaped asteroids under the influence of photons due to the uneven surface albedo. It has been suggested that as a result of this effect, the rotation speed of the asteroid could increase so much that tidal forces would tear it in two.
The sun and the celestial bodies revolving around it under the influence of gravity form the solar system. In addition to the Sun itself, it includes 9 major planets, thousands of minor planets (more often called asteroids), comets, meteorites and interplanetary dust.
The 9 major planets (as they move away from the Sun): Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. They are divided into two groups:
Closer to the Sun are terrestrial planets (Mercury, Venus, Earth, Mars); they are medium in size, but dense, with a hard surface; since their formation, they have come a long way of evolution;
small, and they do not have a hard surface; their atmosphere consists mainly of hydrogen and helium.
Pluto stands apart: small and at the same time of low density, it has an extremely elongated orbit. It is quite possible that he was once a satellite of Neptune, but as a result of a collision with some celestial body, he "gained independence."
solar system
The planets around the Sun are concentrated in a disk with a radius of about 6 billion km - this is the distance light travels in less than 6 hours. But comets, according to scientists, come to visit us from much more distant lands. The closest star to the solar system is at a distance of 4.22 light years, i.e. almost 270 thousand times farther from the Sun than the Earth.
Numerous family
The planets lead their round dance around the Sun, accompanied by satellites. Today, 60 natural satellites are known in the solar system: 1 for the Earth (Moon), 2 for Mars, 16 for Jupiter, 17 for Saturn, 15 for Uranus, 8 for Neptune and 1 for Pluto. 26 of them were discovered from photographs taken from space probes. The largest moon, Ganymede, orbits Jupiter and is 5260 km in diameter. The smallest, no larger than a rock, are about 10 km across. Closest to its planet is Phobos, which revolves around Mars at an altitude of 9380 km. The farthest distant satellite is Sinope, whose orbit passes on average at a distance of 23,725,000 km from Jupiter.
Since 1801, thousands of minor planets have been discovered. The largest of them - Ceres - with a diameter of only 1000 km. Most asteroids are located between the orbits of Mars and Jupiter, at a distance from the Sun 2.17 - 3.3 times greater than that of the Earth. However, some of them have very elongated orbits and may pass close to Earth. So, on October 30, 1937, Hermes, a small planet with a diameter of 800 m, passed only 800,000 km from our planet (which is only 2 times the distance to the Moon). More than 4 thousand asteroids have already been entered into astronomical lists, but every year observers discover more and more new ones.
Comets, when they are far from the Sun, are a nucleus several kilometers across, consisting of a mixture of ice, rocks and dust. As it approaches the Sun, it heats up, gases escape from it, dragging dust particles with it. The core is wrapped in a luminous halo, a kind of "hair". The solar wind blows this “hair” and pulls it away from the Sun in the form of a gas tail, thin and straight, sometimes hundreds of millions of kilometers long, and dusty, wider and more curved. Since ancient times, the passage of about 800 different comets has been noted. There may be up to a thousand billion of them in a wide ring near the borders of the solar system.
Finally, rocky or metallic bodies circulate between the planets - meteorites and meteoric dust. These are fragments of asteroids or comets. Once in the Earth's atmosphere, they burn out, sometimes, though not completely. And we see a shooting star and hurry to make a wish...
Comparative sizes of the planets
As they move away from the Sun, they go: Mercury (diameter about 4880 km), Venus (12,100 km), Earth (12,700 km) with its satellite Moon, Mars (6,800 km), Jupiter (140,000 km), Saturn (120,000 km), Uranus (51,000 km), Neptune (50,000 km) and finally Pluto (2200 km). Planets closer to the Sun are much smaller than those located beyond the asteroid belt, with the exception of Pluto.
Three amazing companions
Large planets are surrounded by numerous satellites. Some of them, photographed close-up by the American probes Voyager (Traveler), have an amazing surface. So, at the satellite of Neptune Triton (1) at the south pole there is a cap of icy nitrogen and methane, from which geysers of nitrogen escape. Io (2), one of Jupiter's four main moons, is covered in many volcanoes. Finally, the surface of Uranus' moon Miranda (3) is a geological mosaic composed of faults, escarpments, meteorite impact craters and huge ice flows.