A nuclear explosion will seem like a trifle: astronomers predicted the death of mankind from a giant meteorite

While we are sleeping or awake, cosmic “messengers” are flying over us. They can be iron, stone, less than a meter, the size of a football field or a mountain. It was with a field 100 meters long that the asteroid 2023 DZ2 turned out to be, which flew 160 kilometers from Earth on the night of March 25-26.

Up to 100 (!) tons of matter falls to Earth from space every day. These are stones from a few grams to tens of tons, such as, for example, the largest of the meteorites – the 66-ton Goba, found in 1920 in Namibia. The main external signs of a meteorite are the melting crust, depressions on the surface and magnetization. In addition, meteorites tend to have an irregular shape.

“The biggest event in the world”

According to the chief researcher of the Ural Federal University, a member of the Commission on Meteorites of the Russian Academy of Sciences Viktor Grokhovsky, despite the fact that star showers from meteors associated with comets “shed” on our planet several times a year, most often on Earth they still find stone meteorites of asteroid origin.

Knowing the speed with which they enter our atmosphere, one can assume their future fate – they will evaporate, forming a huge crater, or remain for millennia, and the crater will be small in size, approximately the size of a stone, as in the case of Goba.

The meteor body, entering the Earth’s atmosphere at high speed, greatly loses mass. Weighing initially from several tens to hundreds of tons, after passing through the dense layers of the atmosphere, it retains only a few kilograms or even grams of matter.

I am interested in Viktor Grokhovsky, why lately we have begun to hear more often about meteorite falls.

– Astronomers have long learned to find asteroids in the sky with a diameter of several hundred meters or more. As for the “stones” of smaller sizes – several tens of meters – “hunting” for them has become possible only since 2008, with the advent of more sensitive optics.

To date, there are seven of them, three of which were even found on Earth: the first in 2008 – in Sudan, the second in Botswana, the third – in northwestern France. In the latter case, a 100-gram fragment remained from the original celestial body of a meter diameter after passing through the dense layers of the atmosphere.

– Have experts determined the place where the Kyiv meteorite fell, which made a lot of noise in the capital of Ukraine on April 19?

– Defined. He was supposed to land near the city of Belaya Tserkov, maybe a little north of it, in the direction of Fastov.

Help “MK”. The most famous Russian fireballs, reminiscent of Kiev in size, from which meteorites could remain: two meteors were recorded in Mordovia and Mari-El last autumn, the third – in the Krasnoyarsk Territory. All three, most likely, fell in a forested area. Unfortunately, it is not yet possible to establish their exact coordinates, since Russia does not have its own so-called fireball network.

– The Chelyabinsk meteorite was ten times larger than the above, but it still wasn’t tracked in time. 10 years after his “visit”, is this “lack of observation” finally fixed?

– The Chelyabinsk meteorite with a diameter of about 19 meters and a mass of about 13 thousand tons in our century is the largest event of this type on the planet.

We can find some of the asteroids that are similar in size to it, but not all, because we do not have the technology that would cover the entire sky. One telescope surveys such a small segment of the sky, which, by analogy with photography, can be compared with only one pixel. By the way, in the West, too, they cannot always track such asteroids.

– We know that the parent body of the stone Chelyabinsk meteorite was an asteroid weighing several tens of thousands of tons, that a total of about two tons of its substance was collected on Earth, that the largest one weighs more than 500 kg. What other mysteries of this heavenly wanderer have you been able to solve over the past decade?

– At the recent scientific readings dedicated to the decade of the meteorite fall, both our and American scientists made a lot of reports. Several of them were devoted to the past of our famous meteorite.

In particular, some researchers have determined by its texture that, flying for billions of years in space, it collided with other bodies of the solar system 6-8 times.

But we, having conducted an experiment, showed that, in principle, such a remelted texture could be obtained with one blow. Our study is more in line with the work of the Japanese scientist Nakamura, who claims to have found minerals containing water in the substance of the Chelyabinsk meteorite. If this is confirmed, it would mean that the asteroid had an encounter with a comet before heading towards Earth.

– Perhaps she “sent” him to us?

– Not excluded.

– Has the frequency with which meteorites like the Chelyabinsk one can arrive to Earth be revealed?

– It is noticed that they fall to the Earth on average once every half a century. Chelyabinsk can be compared with the Sikhote-Alin meteorite that fell in Primorsky Krai 76 years ago, or with the Tunguska event, which occurred almost 115 years ago.

As for those bodies that are larger, they fall much less frequently. For example, the Arizona crater with a diameter of one kilometer was formed over a thousand years as a result of the fall of a 50-meter meteorite.

– Are they watching large, hundred-meter bodies?

– Certainly. According to an international database, there are already 32,000 of those that approach the Earth and cross its orbit. They are under constant surveillance.

The threat is akin to a nuclear explosion

However, to observe is one thing, and to be able to respond to the threat in time, to deflect the blow of the “mountain” flying from space, is not yet within the power of anyone.

Last fall, the Americans conducted only the “first test of planetary defense”: they shot down the Dimorph asteroid 11 million kilometers from Earth from orbit … Meanwhile, everyone understands that it is impossible to stop – after all, there is not a single body in the solar system that would not be attacked other space bodies.

Astronomers attribute not only the cratered Moon to meteorite impacts, but also Uranus “lying on its side” (whose axis of rotation is knocked down so much that it is almost parallel to its orbit), and the absence of a whole planet between Mars and Jupiter, which could also be destroyed by a large asteroid .

Our planet, fortunately, is still intact, but scientists have evidence that it has already met with giant meteorites. This can be evidenced by the largest 300-kilometer crater under the Antarctic ice, there is also a crater over 100 km in diameter in Yakutia …

Around the same time that the craters were formed, life on Earth, according to geological data, was subjected to significant tests. So, science knows that 65 million years ago, as a result of a collision with a large celestial body, most likely a comet, more than 75% of all life on our planet died out. And this situation can happen again.

Of course, serious catastrophes, for example, those that, according to the well-known theory of Luis Alvarez, occur once every 7 million years and kill everyone, we cannot prevent, but we must be prepared to reduce catastrophic consequences as much as possible.

As we know, even the Chelyabinsk meteorite caused real material damage, people suffered. It was a local disaster.

Employees of the Institute of Astronomy of the Russian Academy of Sciences in the work “Threat from the sky. Rock or Chance? defined catastrophes on another level. Thus, the fall of a celestial body to Earth with a diameter of several hundred meters to 1.5 kilometers would cause consequences similar to the largest earthquakes, “explosions” of volcanoes, or even “limited nuclear war”.

“In the ocean, with such a fall, grandiose waves would form – a tsunami. Destruction and fires could cover millions of square kilometers (up to the whole continent). Scientists attributed such consequences to a regional catastrophe.

The consequences of the fall of a celestial body over 1.5 kilometers to Earth would cover the entire globe, that is, the catastrophe would become global.

Of course, the frequency of large-sized meteorites falling is small (in the table of global sources of death, this one is only in 12th place, after diseases, wars, epidemics, famine, accidents, suicides, hurricanes, poisonings and earthquakes). But with each such fall, destruction and casualties on Earth can be significantly greater than with all other catastrophes.

The fall of a large body to Earth, according to scientists, is capable of causing death of people within a few months or years. Based on the results of a nuclear weapons test, scientists have shown that a similar explosion from a huge asteroid impact (1-2 km in size at a speed of 20 km/s) will produce enough dust in the atmosphere that it will cause a decrease in temperatures over most of the land by a few degrees Celsius. Together with other effects: the destruction of the ozone layer, the poisoning of soil and water by acid rain, the death of crops, all this can lead to mass starvation and the death of several billion people, destabilizing the entire human civilization.

Russian “Milky Way”

What if a dangerous body threatening the Earth has already been identified?

Some suggest that in this case, keep thousands (!) kilotons of charges on alert all the time for an emergency repulse of an attack, that is, to have a nuclear bomb at hand that can change its trajectory.

There is a proposal to send a spacecraft with a jet engine to the body and “tow” the dangerous block to another trajectory. We and the Americans have many similar ideas and proposals. But without a coherent planetary defense system, they will all be useless. After all, an asteroid or a comet must first be tracked, and the trajectory must be accurately calculated over several years.

NASA and the European Space Agency have long had a comprehensive program to predict and prevent threats from the sky. How will Roscosmos respond?

Today, Russia has an Automated Warning System for Dangerous Situations in Near-Earth Space (ASPOS OKP), but a new, more modern one has long been expected to replace it.

Everything goes to the fact that at the end of this year there will be a project of the system of information and analytical support for the safety of space activities in the near-Earth space “Milky Way”. It will work to prevent all threats from the sky, including meteorites and space debris.

In mid-April, it became known that the program was approved by the President of the country. Whether the “Milky Way” has something in common with the “Strategic Defense of the Earth”, which was proposed at the time by the previous general director of the state corporation Dmitry Rogozin, is unknown.

It is assumed that the Milky Way system will consist of 65 ground-based telescopes and a satellite constellation for monitoring near-Earth space. It will be conducted not only from the territory of Russia, but also from the territories of South America, the Middle East, Asia and other regions of the planet.