In their opinion, the destruction was caused only by the passage of a cosmic body in the Earth’s atmosphere.
In June 1908, a powerful explosion occurred in the area of the Podkamennaya Tunguska River, which knocked down trees on an area of several thousand square kilometers, caused a number of other destruction, the glow of the sky and glowing clouds. It is still believed that all this was caused by the fall of a meteorite or other cosmic body, but nowadays, scientists have doubted this.
“We calculated the trajectory characteristics for space objects with a diameter of 200 to 50 meters, consisting of iron, ice or rock, such as quartz and lunar soil. The model shows that the Tunguska body could not consist of stone or ice, since the low strength of these internally heterogeneous materials, unlike iron, leads to the rapid destruction of such bodies in the atmosphere under tremendous aerodynamic pressure, ”explained the doctor of physical and mathematical sciences, Leading Researcher, Institute of Physics named after L.V. Kirensky FIC KSC SB RAS, professor of the Institute of Engineering Physics and Radioelectronics of the Siberian Federal University Sergey Karpov.
The team of scientists of the Federal Research Center “Krasnoyarsk Scientific Center of the SB RAS” and representatives of several Russian academic institutes and universities modeled the behavior of a potential space object. The model took into account the trajectory and mass of the space object, the external forces acting on it and changes in the initial velocity, the change in the trajectory of the space body depending on aerodynamic drag, the angle and velocity of entry into the atmosphere, the properties of the body material and its passage through various layers of the atmosphere.
Based on these data, the researchers concluded that the destruction could have been caused by an iron asteroid with a most probable size of 100 to 200 meters, which passed through the Earth’s atmosphere at a minimum flight height of 10-15 kilometers at a speed of about 20 kilometers per second and continued to move in the circumsolar orbit, having lost about half of its initial mass (it could exceed more than 3 million tons), while maintaining its integrity. The shock wave created by such a space object could well create the destruction that was observed in the region where the supposed meteorite fell.
Fires could also be caused by an asteroid – the head of a car with a radiating surface temperature of more than 10,000 degrees at a minimum flight height on the Earth’s surface can create a temperature sufficient to ignite combustible materials. Due to the absorption of optical radiation from the car at the estimated time of flight over the epicenter, trees could catch fire for only 1-1.5 seconds.
The work of scientists, the first results of which are published in the journal Monthly Notices of the Royal Astronomical Society, has not yet been completed. The researchers intend to continue calculating the amplitude of the shock wave in the region of the epicenter under different conditions and changing the temperature of the surface of the asteroid along the trajectory, the development in time of the process of the body passing through the atmosphere, including its destruction.