Just a few years ago … the proposition of the gradual transition of a particle of matter into a particle of life might seem as unsubstantiated, albeit promising, as the first reasoning of Darwin or Lamarck about transformism. But a lot is changing now. Since the time of Darwin and Lamarck, numerous finds have confirmed the existence of transitional forms postulated by the theory of evolution. Likewise, recent advances in biological chemistry are beginning to establish the existence of molecular compounds that close and fill the seemingly gaping gap between protoplasm and mineral matter. And it is very significant that even if they cannot be mixed with a cell, nevertheless, by some of their properties (namely, the ability to reproduce upon contact with living tissue) they already anticipate the properties of properly organized beings.
The likelihood of a catastrophe is very small, but if it does happen, the consequences will be dire. According to the Turin scale, we can assess how dangerous an object crossing the Earth's orbit is, just as we estimate seismic hazard using the Richter scale.
Falls of large asteroids to Earth are extremely rare, but it is with them, and not with small objects like the Tunguska meteorite, that the main danger is associated. The risk of perishing from an asteroid a kilometer in diameter is almost a hundred times higher than from the Tunguska meteorite. However, it is necessary to engage not in statistical calculations, but in a timely search for the very asteroid that may someday crash into the Earth.
The world around us is full of paradoxes, and giant boulders of asteroids arriving from space can not only spread “spores of life” throughout the Universe, changing the course of evolution of living matter, but also extinguish the fragile flame of reason. All kinds of media have long been playing on the rudimentary fears of mankind about future space disasters mirtajn.com, and now they are doing it in a very scientific way. In the press, after living dinosaurs, flying saucers and sinking liners, the predictions of comets and other grandiose cosmic catastrophes are increasingly common. Such themes also arise in cinema, for example, in the famous blockbusters "Meeting the Abyss" and "Armageddon".
The plot of these and many similar films is unpretentious, but effective: a giant asteroid is approaching the Earth. Most of humanity will not survive the upcoming catastrophe, as dinosaurs and lizards did not survive a similar collision of the Earth with a heavenly body tens of millions of years ago. Scientists and heroic astronauts try to prevent disaster, but despite their best efforts, part of the meteorite still falls into the Atlantic Ocean, providing an opportunity for computer graphics and special effects engineers to demonstrate their art.
Of course, this is all pure fantasy, but let's think - really, how real is the collision of the Earth with a giant meteorite and what could be the consequences of such a catastrophe?
Two-thirds of the earth's surface is occupied by seas and oceans, therefore, the fall of the asteroid into the water area of the World Ocean is most likely. Such a blow will generate a powerful wave - a tsunami. More than half of the world's major cities are located on the coast. In 1992, the US space agency NASA prepared a report, which said that when a comet or asteroid falls into the ocean, a huge wave will arise; it will fall on the coast and destroy all living things. Even objects with a diameter of 200 to 1000 meters are dangerous. Astronomers believe: every two and a half centuries, a celestial body with a diameter of at least one hundred meters falls into the ocean, which generates a powerful tsunami. However, American geophysicists have shown that the waves generated by an asteroid falling into the ocean are significantly shorter than the waves generated by an underwater earthquake mirtajn.com. Therefore, they usually go out,before reaching the coast; moreover, their height is insignificant. Based on computer models and calculations, meteorologists tried to estimate the scale of the disaster, taking into account the population density in coastal areas. Scientists have come to the conclusion that the danger threatens about one percent of the population, and this is much less than previously thought. In the calculations of their colleagues, the number of the population at risk was several tens of millions of people. The danger was heightened if the coast was not protected by either natural or artificial barriers.than previously thought. In the calculations of their colleagues, the number of the population at risk was several tens of millions of people. The danger was heightened if the coast was not protected by either natural or artificial barriers.than previously thought. In the calculations of their colleagues, the number of the population at risk was several tens of millions of people. The danger was heightened if the coast was not protected by either natural or artificial barriers.
In the fall of 2004, German geologists discovered traces of a giant wave that swept across the ocean about 200 million years ago. Traces of an ancient catastrophe were found in a layer of rock, and the height of this wave, perhaps, reached several thousand meters. Probably, the wave caused by the fall into the ocean of one or more asteroids swept around most of the Northern Hemisphere, destroying three quarters of all animal species that inhabited our planet.
Promotional video:
The potential meteorite threat of destruction of large cities or devastating tsunamis always exists, because, in fact, the Earth is simply surrounded by a dense swarm of asteroids. Since the thirties of the last century, when the asteroid Hermes with a diameter of one and a half kilometers flew near our planet, more than two dozen large objects were seen that approached the Earth at an extremely dangerous distance. Moreover, the diameter of several of them exceeded a hundred meters!
But, as mentioned above, asteroids do not always pose a threat. After all, perhaps it was they who brought life to our planet, which began with organic molecules of their cosmic gas and dust clouds.
Approximately 450 million years ago, the consequences of a monstrous explosion put an end to the domination of trilobites - the most diverse arthropod inhabitants of the World Ocean. Then, 80 million years later, at the end of the Paleozoic period, the next global catastrophe, also caused by the fall of a celestial body, destroyed the kingdom of corals and fish. But perhaps the worst catastrophe in Earth's history happened 250 million years ago. As a result of this catastrophe, the sky above the planet for many millennia was covered with impenetrable clouds of dust. When the clouds parted, it turned out that from the gigantic army of reptiles that had occupied the land at the time of the disaster at mirtajn.com, only a few species survived. Instead of dead organisms, therapsids have bred on the renewed planet - already very close to mammals. But even these creatures managed to evolve for only two tens of million years. The ark of our planet again swooped down on some heavenly reef or iceberg. Therapsids became extinct, and they were replaced by dinosaurs, the famous Jurassic period, so well known to us from Spielberg's talented film epic "Jurassic Park", came.
The wonderful science fiction writer Harry Garrison in the series of novels "The West of Eden" clearly showed what would have happened to humanity if 65 million years ago another giant meteorite had not burst into the earth's atmosphere. Dinosaurs died out and the era of mammals has finally arrived.
Thus, a space block with a diameter of several hundred meters would be quite enough to destroy European civilization. But there are also much larger celestial bodies. It turns out that shots from disaster films are not so much science fiction as a model of the possible development of events.
As a rule, asteroids are negligible - from a few millimeters to several centimeters, but statistics show that every two hundred years, the Earth meets with space bodies several tens of meters in diameter. And such a "flying rock" may well destroy a multimillion city in a few seconds.
What can be done to prevent such meetings?
First of all, it is necessary to build an interconnected international system for observing outer space within the solar system, in which a powerful central computer should be connected with dozens of space and ground-based telescopes that register all large bodies that appear near the earth's orbit. When detecting asteroids and comets, it is required to immediately calculate their flight path and thus determine whether they pose a potential danger to the Earth.
Now there is a whole network of observatories that monitor our space surroundings. The goal of scientists is to notice the disaster threatening us in time. The accuracy and power of astronomical instruments is constantly growing, and soon humanity will be able to fully control all the near approaches to our planet. And it is so good that asteroids, and even alien spaceships, will have no chance of remaining unnoticed.
It is necessary to fix as many asteroids as possible not only to ensure the safety of the planet, but also for the sake of scientific interest. After all, space debris is a unique material for researchers.
Everyone has probably heard about the Tunguska mystery - an air explosion that occurred in the area of the Podkamennaya Tunguska River on June 30, 1908. The explosion power corresponded to the energy of an average hydrogen bomb. Presumably then the icy nucleus of the comet exploded. In 1989, a kilometer-long rock of dense basalt rocks flew only 690 thousand kilometers from the Earth: the distance on a cosmic scale is negligible. In 1994, a twenty-meter asteroid exploded over the Pacific Ocean near Micronesia.
Approximately once a month, remaining completely unnoticed, some huge asteroid with a football field the size of a football flies past the Earth, and a collision with an asteroid several kilometers in diameter would be fatal for our planet. A fireball flying at a speed of 800 thousand kilometers per hour would destroy all life on earth for tens, if not hundreds of thousands of years. Entire continents could go under water, and the sky would be covered with impenetrable dust clouds. According to experts' calculations, with mirtajn.com the current density of the Earth's population in the event of an asteroid falling, for example, about a kilometer in diameter, every fourth inhabitant of the planet will die. The causes of death will be earthquakes, fires, hurricanes, tsunamis (when an asteroid falls into the sea), as well as hunger caused by climate change, the same as during the "nuclear winter". The catastrophe will have global consequences. The world economy will decline and civilization will be shaken to its very foundations.
Every year, clouds of cosmic dust and micrometeorites cross the Earth's orbit, and a real rain of stars falls on our planet; astronomers have recorded thousands of "shooting stars". Such meteor storms do not pose a real threat to the Earth, although they are capable of breaking through the roof or a car. But for satellites, a meteor shower can be fatal. An asteroid the size of a grain of sand possesses the penetrating power of a bullet fired from a large-caliber rifle.
It turned out that the destructive potential of stone meteorites is not as great as previously thought. In the air, they explode, scattering into small pieces. The area of damage is increasing, but the debris no longer causes a tsunami and major destruction to mirtajn.com. Computer models of such a bombardment demonstrate that all stone meteorites with a diameter of up to two hundred meters disintegrate, while iron meteorites behave as integral fragments.
In the entire "asteroid problem" today, the main difficulty is to predict the appearance of a cosmic meteorite threat with sufficient accuracy and time. Will astronomers be able to do this on the basis of observations with the help of their own, even the most modern instruments? Meanwhile, the most complicated calculations show that the movement of small celestial bodies is very chaotic. Most often, such chaotic wanderings between large planets end with asteroids falling onto Jupiter or the Sun, as well as their ejection outside the solar system. Under the influence of random disturbances, they are able to suddenly change their normal orbit to an extremely elongated one, approaching Mars and creating a potential danger to the Earth.
Even solar wind and light can affect the movement of asteroids and comets. Individual parts of the asteroid facing the Sun are heated more than others. A similar process leads to the fact that the trajectory of the asteroid changes slightly. And these changes are happening all the time. It is possible that sunlight is the reason why asteroids, planetoids and meteorites less than twenty kilometers in diameter invariably move on trajectories that cross the Earth's orbit.
There is no stability in the huge swarm of asteroids. For billions of years, nothing can keep them in the same orbits, so it is very difficult to calculate their behavior. Almost all of them for us are objects with many unknowns: we do not know the exact configuration of these blocks, their structure and composition, their thermal conductivity, their ability to absorb light, and finally, the speed and direction of their rotation. But, for example, the direction in which the asteroid rotates depends on where it starts to move - to Jupiter or the Earth.
We need to compile a catalog of all the celestial bodies that threaten the planet, assess the likelihood of collisions with them and determine whether it is possible to change the trajectory of an object so that it does not collide with the Earth. At the beginning of the third millennium of our era, astronomers have already discovered over three thousand small celestial bodies with a diameter of tens of meters to tens of kilometers, crossing the Earth's orbit, and more or less studied only a few hundred of them. Preliminary theoretical estimates of the total number of dangerous objects already exceed a million!
For a decade and a half, the minor planets that threaten the Earth have been monitored, and an inventory of the heavenly messengers of the deadly threat has been carefully compiled. As part of research programs, it is planned to identify almost all asteroids mirtajn.com with a diameter of more than a kilometer, approaching the Earth at a critical distance of less than fifty million kilometers. Technical capabilities allow space guards to find in the coming decades almost all asteroids with a diameter of more than 300 meters, crossing the Earth's orbit. A cardinal measure in the near future will be the placement of a space observatory with a powerful telescope near the orbit of Venus. In this sector of the solar system, the widest range of observation of asteroids flying towards the Earth opens. By the way,Five or six nuclear-armed ICBMs would be enough to save our planet from most dangerous meteorites. The likelihood that such measures will actually ever be taken, scientists estimate as one in 20 thousand. For comparison, the probability of getting into a car accident is one in a hundred.
It will take decades for scientists and designers to develop a reliable meteorite warning system. And just as much, if not more, time will be required to build "asteroid fighters". In the meantime, not a single large asteroid has been discovered that could threaten the Earth in the foreseeable future. However, the statistics are relentless: someday a collision will occur, which means that we must continue to observe near-Earth space. Ideally, we can predict the likelihood of a space disaster at mirtajn.com decades before. But the main thing is not prediction, but protection.
However, in itself, such a method of dealing with minor planets is also quite dangerous. After all, one cannot be sure that all the debris after the explosion will rush away from the Earth - after an accurate hit on the target, the fragments of the smashed asteroid can fly off to the Earth and wake up on it with hail. Falling them would probably do even more harm than hitting one block. A hail of debris will sprinkle over vast areas of the Earth, causing immense destruction. Therefore, experts are inclined to think that it makes no sense to shoot at an asteroid. It is necessary to make an aimed explosion not far from him. Then the asteroid will be thrown aside. It will go off course, but it will not break into small pieces. Or it is necessary to drill an asteroid and lay a charge in it, which will change the course of the minor planet, but will not destroy it.
However, shooting at celestial targets is still ahead. In the meantime, automatic probes are being created that allow selectively investigating asteroids and comets approaching the Earth. Thus, several research flights mirtajn.com have already been carried out with hard landing vehicles on comets and asteroids. The data on the change in the trajectories of the "celestial icebergs" are now being processed, and further space experiments will make it possible to understand whether it is possible to force the asteroid to roll away from the Earth.
It is also important for scientists to know the composition and structure of asteroids in order to figure out how best to knock them off course. A targeted explosion? Head-on collision? Laser beam? Or maybe equip the asteroid with solar sails? Or engines? What if it is enough to paint or cover a part of the asteroid with something, so that due to the difference in light pressure, he himself turns to the side? Or focus the sun's rays on it with a mirror?
The space era of humanity began with a dozen artificial satellites of the Earth. Now their number is well over a thousand. Such artificial celestial bodies relay television and radio signals, explore the surface and the earth's interior, compile meteorological maps of the movement of air masses, determine the exact location of terrestrial objects, observe deep and near space, conduct numerous scientific experiments and serve military purposes. For orbiting objects, the danger of collision with meteors is quite real, and many expensive orbital complexes have already suffered from small destroyers.
For centuries, astronomers have gazed at the sky with trusting curiosity. Now they are increasingly prompted to observe anxiety. The last time the victims of an asteroid were dinosaurs. Will we be able to do everything possible to make this sacrifice the last?
In June 1999, at a meeting in Turin, the leaders of the International Astronomical Union assessed the danger posed by asteroids and approved a space threat scale, which has since been called the Turin scale.
Depending on their size, speed of movement and the probability of collision with the Earth, all objects receive an index from 0 to 10. This index can change as the trajectory of the asteroid is refined. So far, index 2 ("a collision with the Earth is unlikely to occur, but the object will fly at a close distance from it") has not been assigned to any celestial body mirtajn.com known to us. Even most of the objects listed in category 1 ("the probability of collision is even lower"), after additional observations, were transferred to the zero category ("the probability of collision is practically zero").
However, as it turned out from the polls, any reports about the Turin scale rather scare the public than soothe it. Every time the cosmic threat is spoken of with alarming intonation. Well, the news about the coming end of the world always arouses more interest among the public than the news that again "nothing has happened and nothing will happen."
Until the “end of the world” has come, business people make money “on meteorites”. Thus, insurance companies offer a new type of service - insurance against a meteorite hitting the roof of your house, your car or your head, and travel agencies invite you to go to California or Hawaii in the fall. The meteor shower is best seen there, because the starfall over the ocean is an amazing sight.
