Trajectory of the fall of the apophis. Consequences for the Earth if the asteroid Apophis falls on it

The probability of the Apophis asteroid colliding with Earth in 2036 is practically zero.

This opinion was expressed today at the 7th International Aerospace Congress by Viktor Shor, a leading employee of the Institute of Astronomy at the Russian Academy of Sciences, ITAR-TASS reports.

“In our opinion, when calculating the orbit (of the asteroid), non-gravitational acceleration was not taken into account - the “Yarkovsky effect,” explained Victor Shor. “This effect can greatly change the movement of Apophis.” According to the conclusion of Russian scientists, “the collision of the Earth with Apophis in 2036 has a vanishingly small probability” when taking into account the influence of the “Yarkovsky effect”.

The “Yarkovsky effect,” in particular, manifests itself in a change in the orbit of a body rotating around its axis under the influence of solar radiation, which leads to a rapid evolution of the orbit of cosmic bodies by astronomical standards.

The asteroid Apophis, discovered in 2004, the size of which, according to various estimates, ranges from 200 to 400 meters, has long caused concern among scientists due to the proximity of its passage near the Earth. According to scientists, Apophis will approach the Earth at a dangerous distance of 38 thousand kilometers on April 13, 2029 and may even be visible to the naked eye. However, the likelihood of Apophis colliding with our planet was predicted in 2036, and not in 2029. “Under the influence of the Earth’s gravity, the orbit of Apophis will change,” the expert explained. “The danger is that its orbit is not known accurately enough to calculate the further movement of the asteroid after approaching the Earth.”

“If in 2029 an asteroid passes through the so-called keyhole - a zone only 600 meters wide, then in 2036 it will most likely collide with the Earth. If not, it will fly past, and the danger will pass us,” - Director of the Institute of Astronomy of the Russian Academy of Sciences, member - RAS correspondent Boris Shustov.

It is not possible to accurately predict the collision of an asteroid with the Earth. Observations from Earth and from space do not allow us to calculate the exact orbit and give a correct forecast 20 years in advance.

Currently, scientists from the Russian Institute of Astronomy, the Jet Propulsion Laboratory in the USA and the University of Pisa are working to clarify the orbit of Apophis. As a representative of the Institute of Astronomy noted, the international scientific community differs in its assessment of the orbit of a dangerous cosmic body.

But even if Apophis does not collide with Earth in 2036, this danger could arise again in 2051, 2058, 2066, 2074 and 2089. Scientists estimate that the possible fall of an asteroid will cause enormous destruction over an area of thousands of square kilometers. The force of the impact will exceed the force of the atomic bomb explosion in Hiroshima. If it falls into the seas or large lakes, there will be numerous tsunamis. And all populated areas located near the fall of a cosmic body can be completely destroyed.

To prevent the possible fall of Apophis and other asteroids, various action scenarios are being developed.

"Science already offers many options. For example, deflecting the orbit of an asteroid due to an impact with a special spacecraft or using a space minesweeper or solar sail. It is also proposed to destroy the asteroid with a nuclear explosion. All these methods are still far from real engineering development, and they all work when the orbit of the asteroid is well known. Therefore, in my opinion, now the main task is the “ordinary” task - to observe asteroids, calculate their orbits and assess the probability of a collision. Only after that we need to think about how to divert the asteroid from the Earth, "said a corresponding member RAS Andrey Finkelshtein.

(99942) Apophis (lat. Apophis) is a near-Earth asteroid discovered in 2004 at the Kitt Peak Observatory in Arizona. Preliminary name 2004 MN4, received its proper name on July 19, 2005. Named in honor of the ancient Egyptian god Apep (in ancient Greek pronunciation - Άποφις, Apophis) - a huge serpent, a destroyer who lives in the darkness of the underworld and tries to destroy the Sun (Ra) during its night transition. The choice of such a name is not accidental, since according to tradition, small planets are called by the names of Greek, Roman and Egyptian gods. As a result of its approach to Earth in 2029, the asteroid Apophis will change its orbital classification, so the name of the ancient Egyptian god, pronounced in the Greek manner, is very symbolic. There is also a version that the scientists who discovered the asteroid, D. Tolen and R. Tucker, named it after the negative character from the series “Stargate SG-1” “Apophis”, also taken from ancient Egyptian mythology.

Orbit and close encounters

The asteroid belongs to the aten group, and is approaching the Earth's orbit at a point approximately corresponding to April 13. In 2029, Apophis should pass at a minimum distance of about 37,500 km (according to other sources: 36,830 km, 37,540 km, 37,617 km) from it. After radar observations, the possibility of a collision in 2029 was ruled out, however, due to the inaccuracy of the initial data, there is a possibility of this object colliding with our planet in 2036 and subsequent years. Various researchers estimate the mathematical probability of a collision as 2.2·10−5 and 2.5·10−5. There is also a theoretical possibility of a collision in subsequent years, but it is significantly lower than the probability in 2036.

According to the Turin scale, the danger in 2004 was rated at 4 (Guinness record), but soon [when?] it was lowered to 0.

In October 2009, positional observations of the asteroid were published, made at the Mauna Kea and Kitt Peak observatories on two-meter telescopes between June 2004 and January 2008. Some time later, taking into account new data, scientists at the Jet Propulsion Laboratory (a division of NASA) A recalculation of the trajectory of the celestial body was carried out, which made it possible to significantly reduce the level of the asteroid danger of Apophis. If previously it was assumed that the probability of an object colliding with the Earth is 1:45,000, now this figure has dropped to 1:250,000. According to new data, Apophis will approach the Earth in 2029 by 28.9 thousand km.

Consequences of a possible fall

NASA's initial estimate for the TNT equivalent of an asteroid impact explosion was 1,488 megatons, which was later reduced to 506 megatons after clarification of the size. For comparison: the energy release during the fall of the Tunguska meteorite is estimated at 3-10 Mt; the explosion of the Krakatoa volcano in 1883 was equivalent to about 200 Mt; The energy of the explosion of the “Baby” nuclear bomb over Hiroshima on August 6, 1945, according to various estimates, ranges from 13 to 18 kilotons of TNT.

The effect of the explosion can vary depending on the composition of the asteroid and the location and angle of impact. In any case, the explosion will cause massive destruction over thousands of square kilometers, but will not create long-term global effects like an “asteroid winter.”

According to the simulation, the consequences of the fall of the Apophis asteroid to Earth will be as follows (based on a diameter of 270 meters, a density of 3000 kg/m3, and an atmospheric entry speed of 12.6 km/s):

The collision energy with the Earth is 1717 megatons.

The height of destruction is 49.5 km.

The diameter of the final crater is 5.97 km.

Location of possible Apophis crash sites in 2036

Consequences of the impact of the asteroid Apophis

Consequences of a fall at a distance of 10 km50 km120 km

Earthquake strength (Richter scale) 6.55,64.9

Wind speed792 m/s77.8 m/s44.7 m/s

DestructionCollapse of fortified buildings, collapse of metro tunnels, cracks in the groundDestruction of unfortified buildings, ruptured pipelinesFalling furniture, plaster, minor consequences

If it falls into the seas or large lakes, such as Ontario, Michigan, Baikal or Ladoga, there will be a highly destructive tsunami. All populated areas located at a distance of 3-300 km, depending on the topography of the impact area, can be completely destroyed.

According to the proposals of scientists, to clarify the trajectory and composition of the asteroid, it is necessary to send an automatic interplanetary station (AIS) to it, which will carry out the necessary research and install a radio beacon on it to more accurately measure its coordinates.

In 2008, the American Planetary Society held an international competition of projects to send a small satellite to Apophis for trajectory measurements of the asteroid, in which 37 institute and other initiative teams from 20 countries took part.

Europe (ESA) considers Apophis as one of the goals of the Don Quijote AWS project.

Roscosmos and IKI RAS have projects to send an AMS with the Apophis-P lander to Apophis and to return the soil of the Apophis-Grunt asteroid.

One of the most exotic options suggests that Apophis should be wrapped in highly reflective film. The pressure of sunlight on the film will change the asteroid's orbit.

Roscosmos is considering the possibility of creating its own project to save the Earth from an asteroid fall. Former head of Roscosmos Anatoly Perminov after a meeting with an unnamed scientist:

We will soon hold a closed meeting of our board, scientific and technical council and see what can be done. The mathematical calculations that he (the scientist) presented show that it is possible to make a spacecraft with a special purpose in a timely manner that will avoid this collision...

...the asteroid is not planned to be destroyed. No nuclear explosions, everything is due to the laws of physics. We'll consider it. ...We are talking about people's lives. It is better to pay several hundred million dollars and create a system that will not allow a collision to occur, rather than wait for this to happen and hundreds of thousands of people to die...

In the future, it is planned to involve other countries in this project.
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Asteroid Apophis. Military Secret.

When NASA discovers a potentially dangerous asteroid like Apophis, it doesn't have the authority to decide what to do next. "Rescue planning is not our business," Chesley says. The space agency's first and very timid step in this direction was a working meeting at which possible measures to protect against asteroids were discussed in June 2006.

The Apophis meteorite, rapidly approaching the Earth, with a relatively low probability of falling on its surface, is potentially very dangerous for all life on the planet

A meteorite discovered in 2004, named Apophis (that was the name of the ancient Egyptian serpent god, the antipode of the sun god Ra), when it collides with the Earth, can cause an explosion that will exceed the power of all nuclear bombs in humanity’s arsenal. This conclusion was made by the director of the Institute of Astronomy of the Russian Academy of Sciences, Boris Shustov. The probability of this meeting, which is “scheduled” for 2036, however, is so low that the world’s scientists are not even in a hurry to join forces.

According to Shustov, if a 1-2 kilometer body collides with the Earth, it does not matter where it falls, the effect will be global. “If a body measuring several hundred meters in size, the same 300-meter Apophis, falls, then the consequences will be of a regional scale - the affected area of such an asteroid is the area of an average European country,” Shustov said, speaking in Roscosmos at a conference of the Russian Academy of Cosmonautics named after Tsiolkovsky.

According to Kirill Stikhno, an employee of the Lavochkin NGO, the result of the collision of the Apophis asteroid with the Earth could be an earthquake comparable in strength to the disaster in Haiti. “The consequences of asteroid impacts are not limited to the crater; many of them, when falling, cause shock air waves that sweep away everything in their path. Also, during a fall, a seismic effect may occur,” Stichno told Interfax at a scientific conference at the Bauman Moscow State Technical University.

Shustov claims that the damaging factors from the fall of the astroid will be similar to the consequences of a nuclear explosion, with the exception of the absence of radiation. “The Apophis asteroid carries energy, the destructive power of which in TNT equivalent exceeds the power of all nuclear arsenals on Earth,” the scientist said. That is, in the event of a sad outcome, a region the size of a European country or, say, a city with an agglomeration - such as Moscow and the region will be wiped off the face of the planet (in this regard, it is interesting to recall the etymology of the name of the meteorite, Apophis or Apophis as a snake, as well as the coat of arms of Moscow with George, this conquering serpent, as well as the duties of the residents of the Russian capital to personally justify this coat of arms by standing guard over the planet). Thus, according to NASA, the force of the explosion could be almost two and a half times greater than the force of the eruption of the Krakatoa volcano, which in 1883 almost drowned the Indonesian island on which it stood. And more than ten times the force of the explosion (or fall - depending on what exactly it was with) of the Tunguska meteorite.

At the same time, the scientist consoled that the fall of the Apophis asteroid will not lead to “nuclear winter” and other global consequences, but will have consequences within the region. “We cannot yet say where the asteroid will fall. We can only talk about the probable zone of its fall,” the scientist said. He even presented a slide according to which the impact zone extends from the Urals, along the Russian border with Kazakhstan and Mongolia, through the Pacific Ocean, Central America, the Atlantic Ocean and ends off the coast of Africa.

“The degree of threat from the asteroid is small, it is not as dangerous as journalists claim. The probability of Apophis falling to Earth is only one in 100 thousand,” Shustov said. He noted that with a greater degree of probability it is possible to predict the fall of an asteroid body to the earth in 800 years, and it is precisely something like this that should be feared.

Other Russian scientists share a similar opinion. The head of the Federal Space Agency, Anatoly Perminov, noted that today, when it is obvious that the threat of the fall of the Apophis asteroid, according to calculations, was not so great, the heads of the world's leading space agencies have ceased to pay due attention to this problem. “The fact is that the Apophis asteroid specifically is not very dangerous. But it is possible to test the system and create appropriate spacecraft,” added the head of Roscosmos. He said that “negotiations on this issue have already been held with the European Space Agency and the European Union.” “The matter did not go further than talk,” added Perminov.

How to avoid an explosion

However, the refusal of the world's scientific centers to cooperate in resolving this issue - or in finding ways to prevent similar problems in the future - does not in the least hinder the attempts of domestic scientists to figure everything out on their own. There were three ways to solve this issue. “An asteroid can be impacted impulsively, that is, by an explosion or impact, or it can be gravitational, by bringing a spacecraft of a certain mass towards it. The device, with its gravitational influence, will pull “Apophis” away from the Earth,” the already mentioned Stichno formulated two of the three methods.

One of the first companies to respond to the problem was the Ukrainian State Clinical Hospital “Yuzhnoye” (Dnepropetrovsk). There they proposed using the upgraded Zenit launch vehicle (LV) to eliminate the threat of a collision between the Apophis asteroid and the Earth. As the scientific secretary of the scientific and technical council of the State Clinical Hospital Nikolai Slyunyaev told the Interfax agency in 2009, in particular, we are talking about the possibility of retrofitting Zenit with a new third stage to minimize Apophis getting into the so-called “gravity trap”, which is possible during the flight the asteroid will miss Earth in 2029, with an almost guaranteed chance of impact on its next flyby in 2036.

“The modernized Zenit, with its impulse, changes the trajectory of Apophis and minimizes the possibility of realizing the tragic scenario -2036,” explained a representative of the State Design Bureau. At the same time, according to Slyunyaev, in order to guarantee avoidance of a collision with an asteroid for the next 100 years, it is possible to equip Zenit with a third stage created on new technological principles. “A thousand times more powerful push from the rocket system changes the course of the asteroid so much that the probability of a collision in the next 100 years becomes zero,” he noted.

As the agency's interlocutor clarified, the plane in which Apophis moves, according to experts, is inclined to the equator by 3 degrees. “In this case, it is profitable to carry out launches from a sea cosmodrome near the equator, from where Zenit has launched since 1999,” said Slyunyaev. However, Slyunyaev also counted on help from the United States, Russia and the EU to implement the project.

But this measure is not very popular, in particular because there is a ban on the launch of nuclear weapons into space. So said the director of the Institute of Applied Astronomy of the Russian Academy of Sciences Andrei Finkelstein. True, according to him, “there is a very definite probability: if its trajectory passes through a ‘gate’ approximately 1.5 km in size, then in 2036 it will definitely ‘hit’ us.” Speaking about possible means of combating the asteroid and how humanity can prevent a catastrophe, the scientist emphasized that there are currently no ready-made means. However, he proposed something called a “gravity tractor.”

Another method has been proposed and is being developed by the Keldysh Research Center. Its director and concurrently the president of the Russian Academy of Cosmonautics, Anatoly Koroteev, proposed using already known laws of physics to change the asteroid’s flight path. Thus, a long flight of the spacecraft near Apophis can prevent its collision with the Earth. “If the spacecraft flies near Apophis, then not only will the asteroid influence the spacecraft, but the spacecraft will also influence it. And although the masses are incommensurable and the impact on the asteroid will be small, if you fly near it for a long time, then it can be diverted from the dangerous trajectory of approaching the Earth,” Koroteev told Interfax. Thus, the expert noted, in order to move a potentially dangerous object away from the Earth, there will be no need to exert force on it.

At the same time, Finkelstein reassured the residents of the country, saying that Roscosmos, together with the Ministry of Defense and the Russian Academy of Sciences, is beginning to develop an “anti-asteroid” program, in particular, among the immediate plans is the installation of a locator on the 70-meter telescope in Ussuriysk to receive signals reflected by cosmic bodies. “The Tunguska meteorite showed that the possibility of a collision between the Earth and astronomical bodies is not an invention of scientists, it is a reality,” he said. The scientist did not mention that the fact of the fall of the Tunguska meteorite - as well as its nature, its identification as a meteorite body itself - is still in doubt, and scientists around the world have not come to a consensus about what exactly happened in 1908 year.

Meanwhile, the Lavochkin NPO is developing a spacecraft to study Apophis. According to the director of the Space Research Institute of the Russian Academy of Sciences, Academician Lev Zeleny, in 2029 the asteroid’s trajectory will pass quite close to the Earth, and it would be a sin not to take advantage of this for research purposes. In order to prevent a collision, further study of the asteroid is necessary. NPO named after Lavochkin is developing the device. By the way, the press secretary of the Main Astronomical Observatory of the Russian Academy of Sciences in St. Petersburg, Sergei Smirnov, claims that the first approach to the Earth will occur in 2012, and therefore, perhaps, we need to hurry up with the research of the cosmic body.

The threat is worse

Shustov never tires of intimidating citizens, and at his speech in Roscosmos at a meeting of the conference of the Tsiolkovsky Russian Academy of Cosmonautics, he stated that a thousand asteroids ranging in size from 100 meters to several kilometers potentially threaten the Earth. “About 7 thousand objects approaching the Earth have been discovered, of which 1000 - 1200 are potentially dangerous. Of these, approximately 150 bodies are from 1 km in size, and about a thousand bodies are from 100 m to 1 km in size,” Shustov specified.

According to him, almost all kilometer-long bodies have been discovered and are constantly being observed as part of NASA's Space Guard program. He explained that after the collision of the Earth with a 10-kilometer cosmic body, “all life on the planet may perish, but civilization for sure.” But asteroids of this size fall to Earth once every tens of millions of years.

“Within the limits of the existence of human civilization or human life, small bodies from 100 meters are more dangerous. Their danger is explained simply: they often fall. We need to take inventory of them, monitor them, and prepare for the consequences of a collision with such bodies,” said the head of the Institute of Astronomy of the Russian Academy of Sciences.

On the other hand, it was the fall of the asteroid that allowed the emergence of human civilization, Shustov said. “You know the most popular hypothesis about the extinction of dinosaurs, which says that a body 10 km in size hit the Yucatan Peninsula and led to the extinction of 80% of all life on the planet. At that time, mammals occupied a subordinate position to dinosaurs, but dinosaurs, being cold-blooded, could not withstand the consequences of the collision, and mammals, including humans, entered a promising evolutionary branch. Here we can say thank you to the asteroid,” the scientist said.

Asteroid Apophis in apocalypse theory represents a big event when it comes to colliding with Earth. In particular, if we assume a collision of a large asteroid with the Earth, this would be a terrible destruction of the planet. Apophis is truly a large celestial body, so much so that scientists compare the collision with the explosion of a nuclear bomb.

Could a huge asteroid collide with Earth? This has already happened in planetary history and, of course, the catastrophe can happen again. Fortunately, there is no threat of an asteroid attack today. At least space observers convince us of this.

Apophis was discovered by two researchers from the Kitt Peak National Observatory, located in Arizona, USA. They noticed showing themselves in June in two thousand and four.

Apophis was first designated 2004 MN4. Then he received the nomenclature 99942 after an accurate study of its orbit was made and calculations were performed.

After some time, he was called by his own name Apophis (Apophysis). Presumably because the scientists who discovered it were fanatics of a series of TV shows related to the space where the name was mentioned.

Apophis is today an asteroid, the collision of which with the Earth could cause a planetary catastrophe. The event, of course, will not erase the human race from the list of the Universe, but the consequences for the life of the planet will be terrible.

Astronomers are confident that the Apophis asteroid is one of the most powerful threats to human life on planet Earth.

The huge space rock keeps its orbit very close to our planet. The asteroid's trajectory crosses our planet's orbit twice each time it completes its journey around the Sun.

How dangerous is Apophis for the Earth?

Since its discovery, it was believed that there was a strong threat to the Earth. Because the giant stone makes its way towards our planet. At first there was even an assumption that he was going to enter into a gravitational confrontation with the Earth. This could change the orbit of Apophis so much that the asteroid would collide with the planet.

The megaton composition of this asteroid is so prodigious that it can be compared to twice the energy of Krakatoa. But the then raging volcano led to global climate change on Earth for almost 5 years in the 19th century.

Recent observations made by the European Space Agency (ESA) and NASA reports of a possible collision of Apophis with Earth have ruled out the event. However, it is estimated that it can generate an energy release of 900 megatons!

This could be a disaster that seems worse than the most powerful nuclear bomb created by man. April 13, 2029, the closest date when Apophis will be closest to Earth, fortunately there is no danger for the planet.

Friday, April 13, 2029. This day threatens to be fatal for the entire planet Earth. At 4:36 GMT, asteroid Apophis 99942, weighing 50 million tons and with a diameter of 320 m, will cross the orbit of the Moon and rush towards Earth at a speed of 45,000 km/h. A huge, pockmarked block will contain the energy of 65,000 Hiroshima bombs - more than enough to wipe out a small country from the face of the Earth or rock a tsunami a couple of hundred meters high.
The name of this asteroid speaks for itself - that was the name of the ancient Egyptian god of darkness and destruction, but there is still a chance that it will not be able to fulfill its fatal destiny. Scientists are 99.7% sure that the rock will fly past the Earth at a distance of 30–33 thousand kilometers. In astronomical terms, this is something like a flea's jump, no larger than a round trip from New York to Melbourne, and much smaller than the orbital diameters of many geostationary communications satellites. After dusk, the population of Europe, Africa and Western Asia will be able to observe a celestial object similar to a medium-sized star crossing the area of the sky where the constellation Cancer is located for a couple of hours. Apophis will be the first asteroid in the entire history of mankind that we will be able to clearly see with the naked eye. And then he will disappear - he will simply melt into the black expanses of space.

Every day, approximately 100 tons of interplanetary matter are brought to the earth's surface from space, but only occasionally do objects come to us that would leave a noticeable mark on Earth. Asteroids- rather large cosmic bodies consisting of rock or metal. They originate from relatively warm regions of the inner solar system somewhere between the orbits of Mars and Jupiter. Comets consist mainly of ice and rock. They form in the cold zones of the outer solar system, far beyond the orbits of all the planets. There is a hypothesis that billions of years ago they brought the first organic compounds to Earth. Meteoroids(meteorite bodies) - either fragments of asteroids colliding in outer space, or fragments remaining when comets evaporate. If meteoroids reach the earth's atmosphere, they are called meteors, and if they fall on the earth's surface, they are called meteorites. Currently, 160 craters have been identified on the Earth’s surface, resulting from collisions with cosmic bodies. Here we talk about six of the most notable ones.

50 thousand years ago, Berringer Crater (Arizona, USA), circumference 1230 m

50 thousand years ago, Berringer Crater (Arizona, USA), circumference 1230 m - from the fall of a meteorite with a diameter of 50 km. This is the very first meteorite crater discovered on Earth. It was called “meteorite” (see photo). In addition, it has been preserved better than others. Astronauts trained here in the 1960s, honing techniques for collecting soil samples for the Apollo program.

35 million years ago, Chesapeake Bay crater (Maryland, USA), circumference 85 km

35 million years ago, Chesapeake Bay crater (Maryland, USA), circumference 85 km - from the fall of a meteorite with a diameter of 2–3 km. The largest crater in the United States from a collision with a celestial body. The disaster that created it crushed the bedrock 2 km deep, creating a reservoir of salt water that affects the distribution of underground water flows to this day.

37.5 million years ago, Popigai crater (Siberia, Russia), circumference 100 km

37.5 million years ago, Popigai crater (Siberia, Russia), circumference 100 km - from the fall of an asteroid with a diameter of 5 km. The crater is strewn with industrial diamonds, which were created as a result of the monstrous pressures exerted on the graphite at the moment of impact. According to a new theory, the asteroid that created the crater and the Chesapeake meteorite are fragments of the same larger asteroid.

65 million years ago, Chicxulub basin (Yucatan, Mexico), circumference 175 km

65 million years ago, Chikxulub basin (Yucatan, Mexico), circumference 175 km - from the fall of an asteroid with a diameter of 10 km. The explosion of this asteroid caused a huge tsunami and earthquakes with a magnitude of 10. Scientists believe that it was because of it that dinosaurs became extinct, as well as 75% of all other animal species that inhabited the Earth. Thus ended the Cretaceous period spectacularly.

1.85 billion years ago, Sudbury Crater (Ontario, Canada), circumference 248 km

1.85 billion years ago, Sudbury crater (Ontario, Canada), circumference 248 km - from the fall of a comet with a diameter of 10 km. At the bottom of the crater, thanks to the heat released during the explosion and the water reserves contained in the comet, a system of hot springs arose, which could very likely support life. Along the perimeter of the crater, the world's largest deposits of nickel and copper ore were found.

2 billion years ago, Vredefort dome (South Africa), circumference 378 km

2 billion years ago, Vredefort dome (South Africa), circumference 378 km - from the fall of a meteorite with a diameter of 10 km. The oldest and (at the time of the disaster) the largest of such craters on Earth. It arose as a result of the most massive release of energy in the entire history of our planet. Perhaps this event changed the course of evolution of single-celled organisms.

Memorable meetings with cosmic bodies - the best historical dates!

Maybe it will pass. But scientists have calculated: if Apophis is exactly at a distance of 30,404.5 km from our planet, it should fall into a gravitational “keyhole”. A strip of space approximately 1 km wide, a hole comparable in size to the diameter of the asteroid itself, is a trap where the force of gravity of the Earth can turn the flight of Apophis in a dangerous direction, so that our planet will literally be in the crosshairs at the time of the next visit of this asteroid, which will take place exactly 7 years later - April 13, 2036.
The results of radar and optical tracking of Apophis, when it once again flew past our planet last summer, made it possible to calculate the probability of it getting into the “keyhole”. In numerical terms, this chance is 1:45,000! “It's not an easy task to actually assess the hazard when the probability of an event is very low,” says Michael de Kay of the Center for Information Sharing and Hazard Assessment at Carnegie Mellon University. “Some believe that since the danger is unlikely, then it is not worth thinking about, while others, bearing in mind the seriousness of a possible catastrophe, believe that even the most insignificant probability of such an event is unacceptable.”
Former astronaut Rusty Schweickart has a lot to say about the objects that float in outer space—he was once one himself when he emerged from his spacecraft during the Apollo 9 flight in 1969. In 2001, Schweickart became one of the co-founders of the B612 Foundation and is now using it to put pressure on NASA, demanding that the agency do at least some action regarding Apophis, and as soon as possible. “If we miss this chance,” he says, “it will be criminal negligence.”
Let’s say that in 2029 the situation will not be the best. Then, if we don’t want an asteroid to crash into the Earth in 2036, we must deal with it on approach and try to move it tens of thousands of kilometers to the side. Let's forget about the great technical achievements that we see in Hollywood films - in fact, this task far exceeds the current capabilities of mankind. Take, for example, the ingenious method proposed in the famous “Armageddon”, released in 1998 - to drill a hole a quarter of a kilometer deep in an asteroid and detonate a nuclear charge right inside. So, technically, this is no easier to implement than time travel. In a real situation, when April 13, 2029 approaches, all we have to do is calculate the location of the meteorite fall and begin evacuating the population from the doomed region.
According to preliminary estimates, the place where Apophis fell falls on a strip 50 km wide, running through Russia, the Pacific Ocean, Central America and goes further into the Atlantic. The cities of Managua (Nicaragua), San Jose (Costa Rica) and Caracas (Venezuela) are located exactly on this strip, so they are in danger of a direct hit and complete destruction. However, the most likely place of impact is a point in the ocean several thousand kilometers from the west coast of America. If Apophis falls into the ocean, a crater 2.7 km deep and approximately 8 km in diameter will form in this place, from which tsunami waves will run in all directions. As a result, say, the coast of Florida will be hit by twenty-meter waves that will bombard the mainland for an hour.
However, it is too early to think about evacuation. After 2029, we will no longer have the opportunity to avoid a collision, but long before the fateful moment we can slightly knock Apophis off course - just enough so that it does not fall into the “keyhole”. According to calculations carried out by NASA, a simple “blank” weighing one ton, the so-called kinetic impactor, which should hit the asteroid at a speed of 8000 km/h, will do for this. A similar mission has already been carried out by NASA's Deep Impact space probe (by the way, its name is associated with another Hollywood blockbuster from 1998). In 2005, this device, by the will of its creators, crashed into the nucleus of the comet Tempel 1, and thus information was obtained about the structure of the surface of this cosmic body. Another solution is possible, when a spacecraft with ion propulsion, playing the role of a “gravitational tractor,” hovers over Apophis, and its - albeit insignificant - force of gravity slightly moves the asteroid from its fateful course.
In 2005, Schweickart urged NASA management to plan a rescue mission to install a radio transmitter on Apophis. Data regularly received from this device would confirm the forecasts for the development of the situation. With a favorable forecast (if an asteroid flies past the “keyhole” in 2029), the inhabitants of the earth could breathe a sigh of relief. In the event of a disappointing forecast, we would have enough time to prepare and send into space an expedition capable of averting the danger that threatens it from the Earth. To complete such a project, according to Schweikart's estimates, it could take about 12 years, but it is advisable to complete all rescue work by 2026 - only then can we hope that the remaining three years will be enough to show positive results from the barely noticeable impact on cosmic scales from our rescue ship.

However, NASA still prefers a wait-and-see approach. According to the calculations of Stephen Chesley, who works in Pasadena, California, at the Jet Propulsion Laboratory (JPL) on the Near Earth Project, we have every right to not worry about anything until 2013. By that time, Apophis will be in the field of view of the 300-meter radio telescope located in Arecibo (Puerto Rico). Based on these data, it will already be possible to make a reliable forecast - the asteroid will hit the “keyhole” in 2029 or will fly past it. If the worst fears are confirmed, we will have enough time both for an expedition to install a transceiver and for emergency measures to push the asteroid off a dangerous trajectory. “It’s too early to fuss now,” says Chesley, “but if by 2014 the situation does not resolve itself, then we will start preparing serious expeditions.”
In 1998, the US Congress instructed NASA to search for, record and track all asteroids with a diameter of at least 1 km in near-Earth space. The resulting Space Security Report describes 75% of the 1,100 objects believed to exist. (During these searches, Apophis, which did not reach the required size of 750 m, caught the eye of the researchers simply by luck.) None of the giants included in the “report”, fortunately, pose a danger to the Earth. "But in the remaining couple of hundred that we haven't been able to detect yet, anyone could be on the way to our planet," says former astronaut Tom Jones, a NASA asteroid-hunting consultant. In light of the current situation, the aerospace agency plans to expand the search criterion to a diameter of 140 m, that is, to capture into its network celestial bodies half the size of Apophis, which can nevertheless cause significant damage to our planet. More than 4,000 such asteroids have already been identified, and according to preliminary NASA estimates, there should be at least 100,000 of them.
As the procedure for calculating the 323-day orbit of Apophis showed, predicting the paths along which asteroids move is a troublesome business. Our asteroid was discovered in June 2004 by astronomers at the Arizona National Observatory Kitt Peak. A lot of useful information was obtained by amateur astronomers, and six months later, repeated professional observations and more accurate sighting of the object led to such results that JPL sounded the alarm. JPL's sanctum sanctorum, the Sentry asteroid tracking system (an ultra-powerful computer that calculates the orbits of near-Earth asteroids based on astronomical observations), was making predictions that looked increasingly ominous by the day. Already on December 27, 2004, the estimated chances of a collision expected in 2029 reached 2.7% - such figures caused a stir in the narrow world of asteroid hunters. Apophis took an unprecedented 4th step on the Turin scale.
However, the panic quickly subsided. The results of those observations that had previously eluded the attention of researchers were entered into the computer, and the system announced a reassuring message: in 2029, Apophis will fly past the Earth, but will miss by the slightest. Everything would be fine, but there was one unpleasant little thing left - that very “keyhole”. The tiny size of this gravitational “trap” (only 600 m in diameter) is both a plus and a minus. On the one hand, it would not be so difficult to push Apophis away from such an insignificant goal. If you believe the calculations, then by changing the speed of the asteroid by only 16 cm per hour, that is, by 3.8 m per day, in three years we will shift its orbit by several kilometers. It seems like nonsense, but it’s quite enough to bypass the “keyhole”. Such influences are quite capable of the already described “gravitational tractor” or “kinetic blank”. On the other hand, when we are dealing with such a tiny target, it is impossible to accurately predict which way Apophis will deviate from the keyhole. Today, forecasts of what the orbit will be by 2029 have an accuracy scale (in space ballistics it is called the “error ellipse”) of approximately 3000 km. As new data accumulates, this ellipse should gradually become smaller. In order to say with any certainty that Apophis is flying past, it is necessary to reduce the “ellipse” to a size of about 1 km. Without the necessary information, a rescue expedition may divert the asteroid to the side, or may unintentionally drive it into the hole itself.
But is it really possible to achieve the required forecasting accuracy? This task involves not only installing a transceiver on the asteroid, but also a mathematical model that is incomparably more complex than the one currently used. The new orbit calculation algorithm must also include seemingly unimportant factors such as solar radiation, terms added to account for relativistic effects, and gravitational influence from other nearby asteroids. In the current model, all these amendments have not yet been taken into account.
And finally, when calculating this orbit, another surprise awaits us - the Yarkovsky effect. This is an additional small but steadily acting force - its manifestation is observed in cases when the asteroid radiates more heat from one side than from the other. As the asteroid turns away from the Sun, it begins to radiate heat accumulated in the surface layers into the surrounding space. A weak, but still noticeable reactive force appears, acting in the direction opposite to the heat flow. For example, a twice as large asteroid called 6489 Golevka, under the influence of this force, has moved 16 km away from the calculated orbit over the past 15 years. No one knows how this effect will affect the trajectory of Apophis over the next 23 years. At the moment, we have no idea about the speed of its rotation, or the direction of the axis around which it could rotate. We don’t even know its outlines – but this information is absolutely necessary in order to calculate the Yarkovsky effect.

Fortunately, in order for Apophis not to fall into the gravitational “keyhole”, hiding in space on the approaches to the Earth and ready to send it directly to our planet on the next orbit, it will be enough to move it just a kilometer or two. If we were immediately in danger of a direct collision, the asteroid would need to be “shifted” by 8–10 thousand kilometers and this would require 10,000 times more energy. As it is, it seems that we are capable of the task – even using current technology. Several methods are proposed to solve it.

Strong frontal impact

A spaceship with a warhead, which is a simple blank weighing 1 ton (“kinetic impactor”), will simply crash into Apophis at a speed of 8000 km/h and, according to calculations, will change the speed of an asteroid weighing 50 million tons by only 16 cm per hour. hour. Over the course of three years, the effect of this seemingly insignificant change in speed will accumulate and result in a shift of several kilometers. Advantages. We already know how to do this: last summer, the Deep Impact probe was launched in a similar way to collide with the comet's nucleus. Reverse side. As a result of the collision, fragments may break off from the asteroid. In addition, if the impact does not hit exactly the center of mass, we will achieve not a displacement of the celestial body, but its rotation.

Changing the orbit with a pusher

A plasma or ion rocket engine, powered by a nuclear reactor or solar panels, can be mounted directly on the surface of an asteroid. If it works for at least several weeks, creating a thrust of one or two newtons, this will be enough for the asteroid’s speed to change by the required tens of centimeters per hour. Advantages. The ion thruster design has already been tested during the Deep Space 1 mission in 1998, and the plasma thruster design has been tested during numerous launches of commercial telecommunications satellites and the Smart-1 lunar probe. Reverse side. The spacecraft needs a “soft landing” and rigid attachment to a surface with unknown properties. Since the asteroid is rotating, in order for the thrust to act in only one direction, the device will require a complex control system.

Exposure to tractor

A “gravity tractor” weighing 1 ton, using a solar-powered ion (or plasma) engine or hydrazine shunting engines, will hover at an altitude of a quarter of a kilometer above the surface of the asteroid. The gravitational force of the spacecraft will gradually pull the asteroid away from its trajectory - in fact, the thrust of the engines (that is, several grams of force) will be partially transferred to the celestial body over the course of a month. Advantages. If necessary, all these movements can be controlled. For a gravitational tractor (as opposed to a rigidly fixed pusher), the problems associated with the rotation of the asteroid do not matter. Reverse side. Hovering above the surface is a very unstable position.

Nuclear explosion

If a thermonuclear bomb is planted in the depths of Apophis, it will turn it into a swarm of small asteroids. Advantages. A feeling of deep satisfaction from the mere thought that the enemy has been smashed to smithereens. Reverse side. We have never done deep drilling in outer space before. Besides, wouldn't a bunch of small radioactive asteroids be even worse than one big one?

Nuclear frying

It is better to arrange a nuclear explosion directly above the asteroid. The evaporation of matter from the surface of a celestial body will push it in the opposite direction. Advantages. In such a situation, the rotation of the asteroid will not play a role. Reverse side. Currently, the international ban on the use of nuclear weapons in space remains in force, and stockpiling nuclear warheads for asteroid defense could be detrimental to the overall process of nuclear disarmament.

How to get rid of an annoying asteroid

If apophis is indeed aiming directly at the gravitational “keyhole,” ground-based observations will not be able to confirm this until at least 2021. It may be too late to take any action by then. Let's look at what's at stake (Chesley believes that the fall of such an asteroid should entail losses of $400 billion due to damage to economic infrastructure alone), and it will immediately become clear that some steps to protect against the impending catastrophe need to be taken now, without waiting for confirmation that they will ultimately prove necessary. When will we start? Or, if you look from the other side, at what point can you rely on luck and say that the trouble is over? When will the odds of a successful outcome be ten to one? A thousand to one?
When NASA discovers a potentially dangerous asteroid like Apophis, it doesn't have the authority to decide what to do next. “Rescue planning is not our business,” Chesley says. The space agency's first and very timid step in this direction was a working meeting at which possible measures to protect against asteroids were discussed in June 2006.
If these NASA efforts earn attention, approval, and, most importantly, funding from the US Congress, then the next step will immediately be sending a reconnaissance expedition to Apophis. Schweikart notes that even if the planned “gravity tractor” equipped with a control transceiver is “covered in gold from nose to tail,” its launch is unlikely to cost more than a quarter of a billion. By the way, the release of space fantasies “Armageddon” and “Deep Impact” cost exactly the same amount. If Hollywood was not stingy in shelling out that kind of money in the name of protecting our planet, will the US Congress really not have it? (Credit: David Noland)