The February 15, 2013the inhabitants of the city of Čeljabinskin Russia, attend an event that few human beings can say they have seen: theexplosion of an asteroid In the atmosphere, the so -called “Čeljabinsk meteor”. It was the most powerful explosion of a meteor in over a century. That day, at 09:13 Local timea meteor of 10,000 tons And 15 meters in diameter has exploded among the 30 and 50 km in height Above the skies of Čeljabinsk, south of the Urals, generating ashock wave which has released an equivalent energy to 500 kilotonsabout 30 times The energy of Nagasaki’s atomic bomb. Fortunately, the explosion took place at such an altitude that the most of the energy was absorbed by the atmosphere. However, more than 1000 people were injured Due to the splinters of the windows shatters for the shock wave of the explosion.
Thanks to the popularity of the dashcams in Russia at that time, we have available Numerous videos of the event who helped astronomers discover the origin in the asteroid solar system: the asteroid band Between Mars and Jupiter. This event, fortunately without serious consequences, has helped to give one decisive thrust For the development of modern alert and planetary defense systems, such as the Dart of NASA probe which has shown man’s ability to deflect, albeit slightly, the orbit of a small asteroid. Events like that of Čeljabinsk take place with one frequency of one every 60 years. The last similar event was that of Tunguska, which occurred, always in Russia in 1908.
The explosion of the meteor: what happened during the Čeljabinsk event
The February 15, 2013at 09:13 roomsthe Sky of Čeljabinsk was illuminated by the disintegration of an asteroid Of 15 meters in diameter to 30-5o km of height in the atmosphere. The energy issued by the shock wave, equal to 30 times the atomic bomb of Nagasakiprovoked great damage to the city, causing the injury of almost 1000 people due to the shattering of the glass. The wake of the event was visible throughout the South of the Urals and the northern part of Kazakhstan.
The numerous video testimonies first show a fireball, a bolidewalk the sky at a speed of 40,000-50,000 km/hthen accompanied by a flash of light Lighter than the sun, and several seconds after from the roar of an explosion (the sound travels more slowly than light). The explosion did not completely disintegrate the asteroid, but one residual part fell to the groundaway from the city of Čeljabinsk, impacting with the frozen surface of the Čebarkul lake. Here in fact a fragment of almost 570 kg of weightwhich allowed to accurately determine the chemical composition of the object.
Where the asteroid that exploded in the skies in Russia came from
The videos of the Čeljinsk event are numerous, especially thanks to the popularity of the dashcam for cars and rooms for monitoring traffic in Russia. Astronomes, overlapping the recorded images during the day with the position of celestial objects in that area of sky, managed to determine both the Return speed of the object, around the 60,000 km/his the atmospheric return angle. By combining these data, astronomers have determined that the Čeljinsk asteroid belongs to Asteroids of the Apollo classa group of objects belonging to asteroid band Between Mars and Jupiter, characterized by having Perdielio inside the earth’s orbit around the sun and a semi-axis of the greater orbit than the terrestrial one.
The importance of planetary defense systems
THE’energy of the explosion of Čeljinsk was fortunately almost completely absorbed by the atmosphere. If the impact had taken place at a lower altitude, or if the asteroid had touched the soil, at this hour we would be talking about an unprecedented catastrophic event in the history of humanity. The most worrying aspect, however, is another, or that Nobody had detected the asteroidlargely because it came from the direction of the sun and therefore was invisible in his glow.
The event thus served to give one decisive thrust for the establishment of numerous offices for the Coordination of the planetary defensewhich consists mainly in the implementation of telescopes dedicated to the discovery of objects up to a few tens meters in diameter, potentially on a collision course with the earth. It is precisely through one of these systems that the Asteroid 2024 YR4 has been discovered, which according to the latest estimates has a probability of about 2% of impacting our planet in 2032.
The Čeljinsk event has also convinced many space agencies, including NASA, to allocate more and more funds to the creation of active systems for the deviation of the orbit of asteroids. An example is that of the probe Dart of the NASA at the Italian partnership which, on September 26, 2022, affected the Asteroid Dimorphos 11 million km from the earth, deviating the orbital trajectory around its twin asteroid Didymos.
