Corresponding Member of the Russian Academy of Sciences A. FINKELSTEIN, Institute of Applied Astronomy RAS (St. Petersburg).

Asteroid Ida has an elongated shape, approximately 55 km long and 22 km wide. This asteroid has a small moon, Dactyl (pictured: light dot on the right), about 1.5 km across. Photo by NASA

The Eros asteroid, on the surface of which the NEAR spacecraft landed in 2001. Photo by NASA.

The orbit of the asteroid Apophis intersects the orbit of the Earth. According to calculations, on April 13, 2029, Apophis will pass at a distance of 35.7-37.9 thousand km from Earth.

For two years now, the “Online Interview” section has been running on the website of the journal “Science and Life”. Experts in the field of science, technology, and education answer questions from readers and site visitors. We publish some interviews on the pages of the magazine. We present to our readers an article prepared on the basis of an Internet interview with Andrei Mikhailovich Finkelshtein, director of the Institute of Applied Astronomy of the Russian Academy of Sciences. We are talking about asteroids, observations of them and the possible threat posed by small space objects in the Solar System. Over the four-billion-year history of its existence, our planet has been repeatedly hit by large meteorites and asteroids. The fall of cosmic bodies is associated with global climate changes that occurred in the past and the extinction of many thousands of species of living beings, in particular dinosaurs.

How great is the risk of a collision between the Earth and an asteroid in the coming decades and what consequences could such a collision lead to? The answers to these questions are of interest not only to specialists. In 2007, the Russian Academy of Sciences, together with Roscosmos, the Ministry of Defense of the Russian Federation and other interested departments, prepared a draft Federal Target Program “Asteroid Hazard Prevention”. This national program is designed to organize systemic monitoring of potentially dangerous space objects in the country and provides for the creation of a national early warning system for a possible asteroid threat and the development of means of protection against the possible destruction of civilization.

The solar system is nature's greatest creation. Life arose in it, intelligence arose and civilization developed. The solar system consists of eight major planets - Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune - and more than 60 of their satellites. Small planets, of which more than 200 thousand are currently known, rotate between the orbits of Mars and Jupiter. Outside the orbit of Neptune, in the so-called Kuiper belt, trans-Neptunian dwarf planets move. Among them, the most famous is Pluto, which until 2006 was considered, according to the classification of the International Astronomical Union, the most distant major planet in the solar system. Finally, comets move within the solar system, the tails of which create the impressive effect of “star showers” ​​when the Earth’s orbit crosses them and many meteors burn up in the earth’s atmosphere. This entire system of celestial bodies, rich in complex movements, is perfectly described by celestial-mechanical theories, which reliably predict the position of bodies in the solar system at any time and in any place.

“Star-like”

Unlike the large planets of the solar system, most of which have been known since ancient times, asteroids, or small planets, were discovered only in the 19th century. The first minor planet, Ceres, was discovered in the constellation Taurus by the Sicilian astronomer, director of the Palermo Observatory, Giuseppe Piazzi, on the night of December 31, 1800 to January 1, 1801. The size of this planet was approximately 950 km. Between 1802 and 1807, three more minor planets were discovered - Pallas, Vesta and Juno, whose orbits, like the orbit of Ceres, lay between Mars and Jupiter. It became clear that they all represented a new class of planets. At the suggestion of the English royal astronomer William Herschel, small planets began to be called asteroids, that is, “star-like,” since telescopes could not distinguish the disks characteristic of large planets.

In the second half of the 19th century, due to the development of photographic observations, the number of discovered asteroids increased sharply. It became clear that a special service was needed to monitor them. Before the outbreak of World War II, this service operated at the Berlin Computing Institute. After the war, the tracking function was taken over by the US Minor Planet Center, currently located in Cambridge. The calculation and publication of ephemeris (tables of planetary coordinates for a specific date) was carried out by the Institute of Theoretical Astronomy of the USSR, and since 1998 by the Institute of Applied Astronomy of the Russian Academy of Sciences. To date, about 12 million observations of minor planets have been accumulated.

More than 98% of small planets move at a speed of 20 km/s in the so-called main belt between Mars and Jupiter, which is a torus, at distances from 300 to 500 million km from the Sun. The largest minor planets of the main belt, in addition to the already mentioned Ceres, are Pallas - 570 km, Vesta - 530 km, Hygiea - 470 km, Davida - 326 km, Interamnia - 317 km and Europa - 302 km. The mass of all asteroids taken together is 0.04% of the mass of the Earth, or 3% of the mass of the Moon. I note that, unlike large planets, the orbits of asteroids deviate from the ecliptic plane. For example, the asteroid Pallas has an inclination of about 35 degrees.

NEAs - near-Earth asteroids

In 1898, the small planet Eros was discovered, orbiting the Sun at a distance less than Mars. It can approach Earth's orbit to within a distance of about 0.14 AU. (AU - astronomical unit equal to 149.6 million km - the average distance from the Earth to the Sun), closer than all small planets known at that time. Such bodies came to be called near-Earth asteroids (NEAs). Some of them, those that approach the Earth's orbit but do not enter the depths of the orbit, constitute the so-called Amur group, named after their most typical representative. Others penetrate deep into Earth's orbit and form the Apollo group. Finally, the Aten group of asteroids rotate within the Earth's orbit, rarely leaving its boundaries. The Apollo group includes 66% of NEAs, and they are the most dangerous for the Earth. The largest asteroids in this group are Ganymede (41 km), Eros (20 km), Betulia, Ivar and Sisyphus (8 km each).

Since the middle of the 20th century, astronomers began to discover NEAs on a large scale, and now dozens of such asteroids are being discovered every month, some of which are potentially dangerous. Let me give you a few examples. In 1937, the Hermes asteroid with a diameter of 1.5 km was discovered, which flew at a distance of 750 thousand km from Earth (then it was “lost” and rediscovered in October 2003). At the end of March 1989, one of the asteroids crossed the Earth's orbit 6 hours before our planet entered this region of space. In 1991, the asteroid flew at a distance of 165 thousand km from Earth, in 1993 - at a distance of 150 thousand km, in 1996 - at a distance of 112 thousand km. In May 1996, an asteroid 300 m in size flew by at a distance of 477 thousand km from the Earth, which was discovered only 4 days before its closest approach to the Earth. In early 2002, the 300 m diameter asteroid 2001 YB5 passed at a distance of only twice the distance from the Earth to the Moon. In the same year, asteroid 2002 EM7 with a diameter of 50 m, flying at a distance of 460 thousand km from the Earth, was discovered only after it began to move away from it. These examples are far from exhausting the list of ASZs that arouse professional interest and generate public concern. It is only natural that astronomers point out to their colleagues, government agencies and the general public that the Earth may be considered a vulnerable cosmic target for asteroids.

About collisions

To understand the meaning of collision predictions and the consequences of such collisions, it is necessary to keep in mind that an encounter between the Earth and an asteroid is a very rare occurrence. According to estimates, a collision of the Earth with asteroids 1 m in size occurs annually, 10 m in size - once every hundred years, 50-100 m - once every several hundred to thousands of years, and 5-10 km - once every 20-200 million years . At the same time, asteroids larger than several hundred meters in diameter pose a real danger, since they are practically not destroyed when passing through the atmosphere. Nowadays, several hundred craters (as-troblem - “star wounds”) with diameters from tens of meters to hundreds of kilometers and ages from tens to 2 billion years are known on Earth. The largest known are the crater in Canada with a diameter of 200 km, formed 1.85 billion years ago, the Chicxulub crater in Mexico with a diameter of 180 km, formed 65 million years ago, and the Popigai Basin with a diameter of 100 km in the north of the Central Siberian Plateau in Russia, formed 35.5 million years ago. All these craters resulted from the fall of asteroids with diameters of the order of 5-10 km at an average speed of 25 km/s. Of the relatively young craters, the most famous is the Berringer crater in Arizona (USA), with a diameter of 2 km and a depth of 170 m, which appeared 20-50 thousand years ago as a result of the fall of an asteroid with a diameter of 260 m at a speed of 20 km/s.

The average probability of death of a person due to a collision of the Earth with an asteroid or comet is comparable to the probability of death in a plane crash and is of the order of (4-5) . 10 -3%. This value is calculated as the product of the probability of the event and the estimated number of victims. And in the event of an asteroid impact, the number of victims could be a million times greater than in a plane crash.

The energy released when an asteroid with a diameter of 300 m is struck has the TNT equivalent of 3,000 megatons, or 200,000 atomic bombs similar to the one dropped on Hiroshima. A collision with an asteroid with a diameter of 1 km releases energy with the TNT equivalent of 106 megatons, while the ejection of matter is three orders of magnitude greater than the mass of the asteroid. For this reason, a collision of a large asteroid with the Earth will lead to a catastrophe on a global scale, the consequences of which will be amplified by the destruction of the artificial technical environment.

It is estimated that among the near-Earth asteroids, at least a thousand have a diameter greater than 1 km (to date, about half of them have already been discovered). The number of asteroids ranging in size from hundreds of meters to a kilometer exceeds tens of thousands.

The probability of a collision of asteroids and comet nuclei with the ocean and seas is significantly higher than with the earth's surface, since the oceans occupy more than 70% of the earth's area. To assess the consequences of a collision of asteroids with a water surface, hydrodynamic models and software systems have been created that simulate the main stages of the impact and propagation of the resulting wave. Experimental results and theoretical calculations show that noticeable, including catastrophic, effects occur when the size of the falling body is more than 10% of the depth of the ocean or sea. Thus, for the 1 km-sized asteroid 1950 DA, a collision with which may occur on March 16, 2880, modeling showed that if it falls into the Atlantic Ocean at a distance of 580 km from the US coast, a wave 120 m high will reach the beaches of America in 2 hours, and in 8 hours a wave 10-15 m high will reach the shores of Europe. A dangerous consequence of a collision of an asteroid of noticeable size with a water surface can be the evaporation of a large amount of water, which is released into the stratosphere. When an asteroid with a diameter of more than 3 km falls, the volume of evaporated water will be comparable to the total amount of water contained in the atmosphere above the tropopause. This effect will lead to a long-term increase in the average temperature of the Earth's surface by tens of degrees and destruction of the ozone layer.

About ten years ago, the international astronomical community was tasked with determining the orbital parameters of at least 90% of NEAs with diameters of more than 1 km by 2008 and to begin work on determining the orbits of all NEAs with diameters of more than 150 m. For this purpose, new telescopes were created and are being created, equipped with modern highly sensitive recording systems and hardware and software for transmitting and processing information.

Drama of Apophis

In June 2004, asteroid (99942) Apophis was discovered at the Keith Peak Observatory in Arizona (USA). In December of the same year it was observed at the Siding Spring Observatory (Australia), and at the beginning of 2005 - again in the USA. The Apophis asteroid with a diameter of 300-400 m belongs to the class of Aten asteroids. Asteroids of this class make up several percent of the total number of asteroids whose orbits are inside the Earth's orbit and go beyond it at aphelion (the point of the orbit farthest from the Sun). A series of observations allowed the preliminary orbit of the asteroid to be determined, and calculations showed an unprecedentedly high probability of this asteroid colliding with Earth in April 2029. According to the so-called Turin Asteroid Hazard Scale, the threat level corresponded to 4; the latter means that the probability of a collision and subsequent regional disaster is about 3%. It is this sad forecast that explains the name of the asteroid, the Greek name of the ancient Egyptian god Apophis (“Destroyer”), who lives in the dark and seeks to destroy the Sun.

The drama of the situation was resolved by the beginning of 2005, when new observations were brought in, including radar ones, and it became clear that there would be no collision, although on April 13, 2029 the asteroid will pass at a distance of 35.7-37.9 thousand km from Earth, that is, at the distance of a geostationary satellite. At the same time, it will be visible to the naked eye as a bright point from Europe, Africa and western Asia. After this close approach to the Earth, Apophis will turn into an Apollo-class asteroid, that is, it will have an orbit that penetrates into the orbit of the Earth. Its second approach to Earth will occur in 2036, and the probability of a collision will be very low. With one exception. If, during the first approach in 2029, the asteroid will pass through a narrow area (“keyhole”) with a size of 700-1500 m, comparable to the size of the asteroid itself, then the Earth’s gravitational field will lead to the fact that in 2036 the asteroid with a probability close to unity will collide with the Earth. For this reason, the interest of astronomers in observing this asteroid and increasingly accurately determining its orbit will increase. Observations of the asteroid will make it possible, long before its first approach to the Earth, to reliably estimate the probability of hitting the “keyhole” and, if necessary, to prevent it ten years before approaching the Earth. This can be done using a kinetic impactor (a “blank” weighing 1 ton launched from the Earth, which will hit the asteroid and change its speed) or a “gravitational tractor” - a spacecraft that will affect the orbit of the asteroid due to its gravitational field.

The Unsleeping Eye

In 1996, the Parliamentary Assembly of the Council of Europe adopted a resolution pointing out the real danger to humanity from asteroids and comets and calling on European governments to support research in this area. She also recommended the creation of an international association “Space Guard”, the founding act of which was signed in Rome in the same year. The main task of the association is to create a service for observing, tracking and determining the orbits of asteroids and comets approaching the Earth.

Currently, the most extensive studies of ASZ are being conducted in the United States. There is a service there, supported by the National Space Agency (NASA) and the US Department of Defense. Asteroid observation is carried out according to several programs:

The LINEAR (Lincoln Near-Earth Asteroid Research) program, carried out by the Lincoln Laboratory in Soccoro (New Mexico) in cooperation with the US Air Force on the basis of two 1-meter optical telescopes;

NEAT (Near Earth Asteroid Tracking) program conducted by the Jet Propulsion Laboratory on the 1-meter telescope in Hawaii and on the 1.2-meter telescope at Mount Palomar Observatory (California);

The Spacewatch project, which involves reflecting telescopes with diameters of 0.9 and 1.8 m at the Kitt Peak Observatory (Arizona);

LONEOS (Lowell Observatory Near-Earth Object Search) program on the 0.6-meter telescope at the Lovell Observatory;

The CSS program, carried out at the 0.7-meter and 1.5-meter telescopes in Arizona. Simultaneously with these programs, radar observations of more than 100

near-Earth asteroids on radars at Arecibo (Puerto Rico) and Goldstone (California) observatories. Essentially, the United States currently plays the role of a global outpost for detecting and tracking NEAs.

In the USSR, regular observations of asteroids, including those approaching the Earth, were carried out at the Crimean Astrophysical Observatory of the USSR Academy of Sciences (CrAO). By the way, for many years it was CrAO that held the world record in the discovery of new asteroids. With the collapse of the USSR, our country lost all the southern astronomical bases where asteroid observations were carried out (KrAO, Nikolaev Observatory, Evpatoria Space Communications Center with a 70-meter planetary radar). Since 2002, observations of NEAs in Russia have been carried out only on a modest semi-amateur 32-centimeter astrograph at the Pulkovo Observatory. The work of the group of Pulkovo astronomers evokes deep respect, but it is obvious that Russia needs significant development of astronomical resources to organize regular observations of asteroids. Currently, organizations of the Russian Academy of Sciences, together with organizations of Roscosmos and other ministries and agencies, are developing a draft Federal program on the problem of asteroid-comet hazard. Within its framework, it is planned to create new tools. As part of the Russian space program, it is planned to create a radar based on the 70-meter radio telescope of the Space Communications Center in Ussuriysk, which can also be used for work in this area.

TsNIIMash and NPO im. S. A. Lavochkina proposed projects for the creation of space systems for monitoring NEAs. All of them involve the launch of spacecraft equipped with optical telescopes with mirrors up to 2 m in diameter into various orbits - from geostationary to those located at distances of tens of millions of kilometers from the Earth. However, if these projects are implemented, it will be only within the framework of the largest international space cooperation.

But now a dangerous object has been discovered, what to do? Currently, several methods of combating ASZ are being theoretically considered:

Deflection of an asteroid by impacting it with a special spacecraft;

Removing an asteroid from its original orbit using a space minesweeper or solar sail;

Placing a small asteroid on the trajectory of a large near-Earth asteroid;

The destruction of an asteroid by a nuclear explosion.

All these methods are still very far from real engineering development and theoretically represent a means of combating objects of different sizes, located at different distances from the Earth and with different predicted dates of collision with the Earth. In order for them to become real means of combating NEAs, it is necessary to solve many complex scientific and engineering problems, as well as agree on a number of delicate legal issues relating, first of all, to the possibility and conditions of using nuclear weapons in deep space.

Sometimes asteroids (or other space objects) crash into the Earth, leaving craters on continents, fall into the ocean, or explode in the atmosphere.

Scientists call this event a collision with Earth. Most asteroids are usually small and do not cause any problems. But from time to time catastrophic falls occur.

When will the next big clash be?

First of all, we must be clear about what we mean by “big impact.” Typical definition: large enough to cause a regional or planetary catastrophe unprecedented in human history in the form of a series of earthquakes, a “nuclear” winter, or a devastating tsunami.

If we knew exactly the position, speed, shape and size of every moderately large object in the solar system, we could use physics and mathematics and predict simply and effectively where and when things might happen! Unfortunately, humanity has not yet cataloged all moderately large (or similar) objects, since they are not all yet discovered and new asteroids and comets continue to be discovered.

Today, for all the large asteroids that we know about, the best we can do is determine the probability of impact with Earth and estimate the amount of possible damage to the planet from this impact. To assess the danger of an object, the so-called Turin Scale or Torino scale was invented - a table showing the degree of danger emanating from a certain celestial object (for example, an asteroid). The Turin Scale uses values ​​from 0 to 10. 0 (zero) means that the probability of an object colliding with the Earth is so small that it falls into observational error. 10 means that a collision is inevitable, and it will lead to global consequences. The magnitude of the danger according to the Turin Scale is determined based on the mathematical probability of a collision and the kinetic energy of the collision.

So, what large asteroids do we know are most likely to crash into Earth in the near future?

Current leaders in the list of the most dangerous asteroids

There is a table where you can see this - Sentry Risk Table, led by NASA. Look in the Torino column (Turin Scale) for objects of danger level 1 or higher. At the time of this writing, only two of these asteroids exist, each with a level 1 Torino scale:

Asteroid 2007 VK184

Asteroid 2013 TV135

1st hazard class according to the Turin Scale

1st class is the lowest on the Turin Scale. This means that there is virtually no risk of the Earth colliding with the most dangerous asteroids. But it is still non-zero. However, further observations may virtually eliminate the risk of collision altogether. Thus, in January 2013, NASA completely ruled out the possibility of a collision with the Earth by the asteroid Apophis, which for a long time was the leader of the asteroid danger and had (initially) level 4 on the Turin scale.

Asteroid 2007 VK184

Asteroid 2007 VK184 was discovered by the Catalina Sky Survey in 2007 and has a 1:3000 chance of impacting Earth. This is the highest probability of a collision with Earth for all asteroids known today. If a collision with it occurs, the asteroid (most likely) will break up in the atmosphere into several separate parts. However, these individual pieces will still be quite large and could cause widespread destruction and lead to numerous casualties if an asteroid falls in densely populated areas. For comparison, the fall of the Tunguska asteroid (or comet) in 1908 was caused by an object with dimensions of 30-50 meters. This size was enough to produce an air explosion of 40-50 megatons. The power of the explosion of the Chelyabinsk meteorite ranged from 0.4 to 1.5 megatons with an object size of 17 meters and a mass of 10 thousand tons.

Asteroid 2013 TV135

Asteroid 2013 TV135. Photo: The Virtual Telescope Project 2.0

The 440-meter asteroid 2013 TV135 was discovered in the current year 2013 and as a result of observations, the probability of its collision with the Earth in 2032 increased from 1:63000 to 1:9009. The impact probability is less than that of Asteroid 2007 VK184, but this probability is still quite high, given the fact that the consequences of Asteroid 2013 TV135 hitting Earth could cause destruction in a radius of 260,000 square kilometers and cause significant changes in the planet's climate in the future.

Predicting collisions by analyzing Earth's history

Vredefort Crater is the largest and oldest known meteorite crater, located in South Africa.

There is another way to calculate the probability of a large object colliding with the Earth - this is to study everything we know about past events:

Objects with sizes ranging from 5-10 meters in width.
Impact Earth about once a year and release more energy than the atomic bomb dropped on Hiroshima. They usually go undetected because most of the Earth's surface is uninhabited and the energy is most often released high in the planet's atmosphere.

Objects measuring 50 meters wide.
They collide with the Earth approximately once every 1000 years (the Tunguska meteorite is just such a case).

Objects measuring 1000 meters wide.
Collide with Earth approximately once every 500,000 years.

Objects measuring 5000 meters wide.
Collide with Earth approximately once every 10 million years.

Even larger objects also crashed into the Earth.
The object that hit Earth 65 million years ago, blamed (at least in part) for the extinction of the dinosaurs, was about 10,000 meters wide and caused an explosion with a yield of 100,000 gigatons. After the fall of this giant asteroid (or comet), 16% of existing families of marine animals and 18% of families of land vertebrates disappeared. There is an assumption that the tsunami caused by this catastrophic explosion reached 100 meters in height. And the dust cloud from the explosion blocked the sun for several years. The sediments caused by the explosion at the end of the Cretaceous period formed a layer of sediment with high levels of iridium and osmium (elements of extraterrestrial origin), which, according to scientists, could not have occurred naturally on Earth.

Instead of a conclusion

Another place where you can look at data on the most dangerous asteroids for Earth is the list NEODyS "Risk list", which is led by a European consortium.

Both the list and the NASA table and the European “Risk list” demonstrate that, at least in the near future, nothing threatens humanity, since astronomers do not know of sufficiently large space objects with a high probability of colliding with the Earth. In addition, based on historical facts, it can be predicted that in this and the next century the probability of a planet colliding with a truly large object is negligibly small.

However, it should be noted that both the American and European lists of dangerous objects do not include objects with large, highly elliptical orbits (such as many comets). They also do not include objects with hyperbolic orbits—objects that fly through the solar system and disappear into space forever, never to return.

In addition, the lists cover only objects known in near-Earth space and, naturally, do not include yet unknown (undetected) objects. According to astronomers, there are at least 500,000 of them. For comparison: at the moment, data has been collected on only 10 thousand asteroids. So danger can come at any moment - from where they were not expected, and a hitherto unknown celestial object can forever change life on our Earth.

© You can copy a post only if there is a direct indexed link to the site

At the beginning of the month, we told you about an asteroid that flew dangerously close to our planet. This has led many people to wonder what we might be able to do if a space visitor actually lands on our heads.

While our natural inclinations will tempt us to scream in fear or call upon every known god, there is actually quite a lot we can do to prepare, respond appropriately, and perhaps even stop a threatening object that the Earth may encounter.

Do not panic

Asteroids and comets pose a threat. They are actually real and dangerous to our planet. Nevertheless, scientists have not been idle all this time. NASA has mapped the positions and trajectories of 90% of the largest near-Earth objects, those with diameters equal to or greater than 1 km. The impact of any such object could cause worldwide devastation, global cooling and mass extinction.

The good news is that none of them appear to pose a threat, so at least on that front we can rest easy. Scientists know about 15,000 of the probable 1,000,000 near-Earth objects. In addition, both NASA and the European Space Agency have programs dedicated to discovering as many of them as possible.

Risk of collision with small objects

NASA currently has a goal of detecting 90% of near-Earth objects larger than 140 meters. These objects are of greater concern as only about 8,000 of them have been discovered so far. All of them have sizes from 100 to 1000 meters. If one of these objects collides with land, it could create a crater the size of a small city. If such an object hits the ocean, it will cause a tsunami.

Smaller objects won't be too dangerous if they fall into the water, but they can cause problems on land. They will likely burn up in the atmosphere, but the shock wave can still be very dangerous. The Chelyabinsk meteorite, for example, which fell in Russia in 2013, damaged more than 7,200 buildings and injured 1,491 people. But it was only 20 meters in diameter!

Initiatives such as Asteroid Day have been created to raise awareness of this danger.

Asteroid Apophysis

Although the threat undoubtedly exists, we have a chance of never facing it. The largest object that will fly near our planet is the asteroid Apophysis. It will first approach Earth in 2029, and then again in 2036. There is only a one in 250,000 chance it will hit Earth, but its first close encounter could change its orbit slightly, making it more dangerous.

Rescue Options

But if we detect a near-Earth object heading towards our planet, will we have the ability to protect ourselves? A group of experts discussed this topic last December, and they concluded that humanity is not currently prepared to destroy the asteroid or avoid such threats.

Our main enemy is time. We might be able to prepare technology capable of destroying or deflecting a celestial body, but it is unlikely that we will have enough time to launch it. Scientists are currently studying the best strategies for dealing with asteroids so that they have a plan in place to protect humanity.

Scientists are still discussing several options for salvation. These include a nuclear option, the ability to use lasers to hook an object and drag it further away from Earth, or a fast missile that will simply crash into it. But we can't just use one of them. There are many variables to consider, such as the size of the property, its density, distance from us, etc., before making plans for unforeseen problems.

Dr. Katherine Plesko said during the conference that scientists need this data before they can start making calculations and creating defenses. But they can only be obtained when the object approaches.

However, lack of protection does not make us helpless. NASA and the Federal Emergency Management Agency have already run three simulated scenarios of how we might intervene if we find ourselves in such danger. Both agencies have generated several scenarios for potential future use. This ensures that they have information that will be critical in such an emergency.

Can I use a film script?

Some of these plans may seem futile, but remember that real life is not like the movies Deep Impact or Armageddon. We can't fly a spaceship to a meteorite and leave a bomb on it to detonate at the last second. Even if we can land the crew, it will be too late, since the meteorite will be very close.

In addition, landing the crew would be incredibly difficult. Asteroids and comets are tiny on a cosmic scale. Comet Churyumov-Gerasimenko, for example, has a gravitational acceleration almost a million times less than on Earth. Landing the Philae probe on it was a phenomenal feat of engineering, and even so, things didn't go exactly according to plan. The probe bounced three times before settling.

So landing on a target that threatens us and sending a group of untrained civilians in to blow it up isn't such a good idea, even though it works in the movies. This could lead to the destruction of a space station or the disintegration of an asteroid, so that hundreds of fragments would eventually begin to approach Earth in unpredictable orbits.

What to do?

There's no reason to lose sleep and constantly fear the possibility of a potential asteroid impact, but at the same time, we can't bury our heads in the sand. So what can we all do to prepare? Worry less about stocking up on essential products and do more to raise awareness of the issue.

Ideally, scientists want to create a special space observatory to observe these objects and a rocket (or even several) ready to take off if necessary. All this, of course, costs too much, but we are talking about preparing for the salvation of all humanity.

Disaster movies always show humanity coming together and working hard even in the face of impossible odds. Perhaps this is the most realistic part of such paintings.

The Chelyabinsk bolide attracted attention to space, where asteroids and meteors can be expected to fall. Interest in meteorites, their search and sale has increased.

Chelyabinsk meteorite, photo from Polit.ru website

Asteroid, meteor and meteorite

Flight paths asteroids designed for a century ahead, they are constantly monitored. These cosmic bodies, potentially dangerous to the Earth (a kilometer or more in size), shine with light reflected from the Sun, so from the Earth they appear dark part of the time. Amateur astronomers are not always able to see them, as city lighting, haze, etc. interfere. Interestingly, most asteroids are discovered not by professional astronomers, but by amateurs. Some are even awarded international prizes for this. There are such astronomy lovers in Russia and other countries. Russia, unfortunately, is losing due to a lack of telescopes. Now that the decision to fund work to protect the Earth from the threat of space has been announced, scientists have hope of purchasing telescopes that can scan the sky at night and warn of impending danger. Astronomers also hope to obtain modern wide-angle telescopes (at least two meters in diameter) with digital cameras.

Smaller asteroids meteoroids flying in near-Earth space outside the atmosphere can be noticed more often when they fly close to the Earth. And the speed of these celestial bodies is about 30 - 40 km per second! The flight of such a “pebble” to Earth can be predicted (at best) only one or two days in advance. In order to understand how little this is, the following fact is indicative: the distance from the Moon to the Earth is covered in just a few hours.

Meteor looks like a shooting star. It flies in the Earth's atmosphere, often decorated with a burning tail. There are real meteor showers in the sky. It is more correct to call them meteor showers. Many are known in advance. However, some happen unexpectedly when the Earth encounters rocks or pieces of metal wandering in the solar system.

Bolide, a very large meteor, appears to be a fireball with sparks flying in all directions and a bright tail. The bolide is visible even against the background of the daytime sky. At night it can illuminate huge spaces. The path of the car is marked by a smoky stripe. It has a zigzag shape due to air currents.

When a body passes through the atmosphere, a shock wave is generated. A strong shock wave can shake buildings and the ground. It generates impacts similar to explosions and roars.

A cosmic body that falls to Earth is called meteorite. This is the rock-hard remnant of those meteoroids lying on the ground that were not completely destroyed during their movement in the atmosphere. In flight, braking begins from air resistance, and kinetic energy turns into heat and light. The temperature of the surface layer and air shell reaches several thousand degrees. The meteor body partially evaporates and ejects fiery drops. Meteor fragments cool quickly during landing and fall to the ground warm. On top they are covered with melting bark. The place of fall often takes the form of a depression. L. Rykhlova, head of the department of space astrometry at the Institute of Astronomy of the Russian Academy of Sciences, reported that “about 100 thousand tons of meteoroid matter fall on the Earth every year” (“Echo of Moscow”, February 17, 2013). There are very small and quite large meteorites. Thus, the Goba meteorite (1920, South-West Africa, iron) had a mass of about 60 tons, and the Sikhote-Alin meteorite (1947, USSR, which fell as iron rain) had an estimated mass of about 70 tons, 23 tons were collected.

Meteorites are composed of eight main elements: iron, nickel, magnesium, silicon, sulfur, aluminum, calcium and oxygen. There are other elements, but in small quantities. Meteorites vary in composition. Basic: iron (iron combined with nickel and a small amount of cobalt), stony (compound of silicon with oxygen, possible inclusions of metal; small round particles are visible on the fracture), iron-stone (equal amount of stony substance and iron with nickel). Some meteorites are of Martian or lunar origin: when large asteroids fall on the surface of these planets, an explosion occurs and parts of the surface of the planets are thrown into space.

Meteorites are sometimes confused with tektites. These are small black or greenish-yellow molten pieces of silicate glass. They are formed when large meteorites impact the Earth. There is an assumption about the extraterrestrial origin of tektites. Externally, tektites resemble obsidian. They are collected, and jewelers process and use these “gems” to decorate their products.

Are meteorites dangerous for humans?

There have been only a few recorded cases of meteorites directly hitting houses, cars or people. Most meteorites end up in the ocean (which is almost three-quarters of the earth's surface). Densely populated and industrial areas occupy a smaller area. The chance of hitting them is much less. Although sometimes, as we see, this happens and leads to great destruction.

Is it possible to touch meteorites with your hands? They are not believed to pose any danger. But you shouldn’t take meteorites with dirty hands. They are advised to immediately put them in a clean plastic bag.

How much does a meteorite cost?

Meteorites can be distinguished by a number of characteristics. First of all, they are very heavy. On the surface of the “stone,” smoothed out dents and depressions (“fingerprints on clay”) are clearly visible; there is no layering. Fresh meteorites are usually dark because they melt as they fly through the atmosphere. This characteristic dark fusion bark is about 1mm thick (usually). A meteorite is often recognized by the blunt shape of its head. The fracture is often gray in color, with small balls (chondrules) that differ from the crystalline structure of granite. Iron inclusions are clearly visible. Due to oxidation in air, the color of meteorites that have lain on the ground for a long time becomes brown or rusty. Meteorites are highly magnetized, which causes the compass needle to deflect.

The development of technologies, with the help of which it became possible to study space in detail, has allowed humanity to learn a lot of information about the space surrounding our planet. As it turned out, many objects move around the Earth: these are not only stars, there are a large number of smaller celestial bodies called asteroids. But, despite the fact that in size they cannot be compared with even the smallest known planet, for humanity they are the most dangerous space formations. Moreover, history knows asteroids falling to earth in past.

Recently, reports about objects that may soon collide with the Earth have begun to appear in the media with noticeable frequency. In 2013, Apophis approached Earth, listed in the Guinness Book of Records as the most dangerous asteroid. Today the Internet is full of messages about an approaching celestial body called Florence. However, scientists report: this time everything will go fine and there will be no collision.

But the approach of bodies to our planet does not always end so happily. Some of them still overcome the atmosphere and fall to the earth's surface.

Asteroids falling to earth. Huge crater in Africa

Photo: economictimes.indiatimes.com

When the Solar System was very young, collisions between objects of different sizes were not a rare occurrence. Proof of this is the surface of the Moon and planets that lack a “natural shield” - an atmosphere.

Our planet has also seen many similar disasters in its lifetime. Scientists have discovered traces of the oldest of them. The cosmic body that “kissed” the Earth 3.3 billion years ago was truly gigantic in size - its diameter was about 50 km. For comparison, the famous Apophis, which humanity feared quite recently, is only 250-400 meters in diameter.

Photo: antikleidi.com

An asteroid that fell in South Africa caused colossal destruction. A shift of tectonic plates, an earthquake that reached a magnitude of 10, a tsunami, and the earth’s surface burned for thousands of kilometers are horrifying phenomena for which scientists are still finding evidence.

Asteroids falling to earth. Sudbury - the source of Canada's wealth

Photo: Roogirl.com

The “space bomb” that hit Earth about 1.8 billion years ago pierced the earth’s crust to the mantle, turning the inner layers to the surface. Its fragments scattered over a huge distance.

But modern inhabitants of the planet, born much later than the disaster, were even able to benefit from the collision. The Sudbury region is one of the largest mineral deposits in Canada. And the soil, rich in minerals left behind by the magma, is ideal for agriculture.

Asteroids falling to earth. Chiklusub - the death of dinosaurs

Photo: Isbn-10.xyz

66 million years ago, the Earth was completely different from what we see today. It was inhabited by creatures that can now only be seen in films. At that time, dinosaurs were the masters of the planet.

For a long time, no one could understand what caused the extinction of the dominant species at that time. And only in the 20th century it was suggested that the disappearance of many thousands of living beings was a consequence of the fall of a huge celestial body.
Photo: Dinocreta.com

It is believed that the Earth collided with a very large asteroid. The impact of enormous force provoked many disasters that led to the almost complete disappearance of life. Of course, a small part of living creatures (mostly small in size) were able to adapt to the dramatically changed conditions. But the dinosaurs disappeared forever.

The site of the asteroid impact is a crater located near the city of Chiklusub, which received the same name as this locality. Judging by its size, the body that collided with the ground had a diameter of 10 km.

Asteroids falling to earth. Tunguska meteorite - the mystery of the century

Photo: Baricada.ro

At the beginning of the 20th century, or more precisely in 1908, a space object rushed to the surface of the earth, which later became known as the Tunguska meteorite. Residents of settlements located in the immediate vicinity of the crash site could observe many unusual phenomena associated with this event: nights as bright as day, thunder in a cloudless sky and a grand explosion.

But the crater from the fall of the celestial body was never discovered. This fact caused a great resonance in the scientific community. Scientists have put forward many theories, ranging from the landing of an alien ship to the fall of an icy comet. None of them have yet been recognized as official.

Asteroids falling to earth. Chelyabinsk disaster

Photo: News.pn

An unexpected event happened on February 15, 2013. An unnoticed asteroid flew up to the Earth and collided with its surface in the region of Chelyabinsk, one of the largest industrial centers in Russia.

Photo: Chinadaily.com.cn

The fact that the appearance of this celestial object was not predicted by scientists is explained by the fact that it approached our planet from the direction of the Sun, and it was impossible to notice it through a telescope. It’s scary to even think what would have happened if the size of the asteroid were not 6 m in diameter, but much larger. After all, even the explosion of such a relatively small cosmic body is several dozen times greater than the explosion of a nuclear bomb dropped on Hiroshima, although its consequences were not as catastrophic.

The end of the world is often associated with a collision with a large asteroid. We can only hope that humanity will never see such a catastrophe. But, given the number of objects that fly dangerously close to the Earth every year, the likelihood that someday a large meteorite will still crash into it is very high.

That's all we have. We are very glad that you visited our website and spent a little time to gain new knowledge.

Join our