In their opinion, the destruction was caused only by the passage of a cosmic body in the Earth's atmosphere.
In June 1908, in the area of the Podkamennaya Tunguska River, a powerful explosion occurred, which knocked down trees in an area of several thousand square kilometers, caused a number of other destruction, the glow of the sky and glowing clouds. Until now, it is believed that all this was caused by the fall of a meteorite or other cosmic body, but today scientists have doubted this.
“We have calculated trajectory characteristics for space objects with a diameter of 200 to 50 meters, consisting of iron, ice or rocks 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 inhomogeneous materials, unlike iron, leads to the rapid destruction of such bodies in the atmosphere under conditions of colossal aerodynamic pressure, "explained the doctor of physical and mathematical sciences. Leading Researcher at the L. V. Kirensky FRC KSC SB RAS, Professor of the Institute of Engineering Physics and Radioelectronics of the Siberian Federal University Sergey Karpov.
A team of scientists from the Federal Research Center "Krasnoyarsk Scientific Center of the Siberian Branch of the Russian Academy of Sciences" and representatives of several Russian academic institutes and universities have 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 the aerodynamic resistance, the angle and speed 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 came to the conclusion that the destruction could have been caused by an iron asteroid with the most probable size of 100 to 200 meters, which passed through the Earth's atmosphere at a minimum flight altitude of 10-15 kilometers at a speed of about 20 kilometers per second and continued to move in a circumsolar orbit, having lost about half of its initial mass (it could exceed 3 million tons), while maintaining its integrity. The shock wave created by such a space object could well have created the destruction that was observed in the area of the supposed meteorite fall.
Fires could also be caused by an asteroid - the head of a bolide with a radiating surface temperature of over 10,000 degrees at the minimum flight altitude on the Earth's surface is capable of creating a temperature sufficient to ignite combustible materials. Due to the absorption of optical radiation from the fireball at the estimated time of flight over the epicenter, trees could catch fire in just 1−1, 5 seconds.
The work of scientists, the first results of which were published in the Monthly Notices of the Royal Astronomical Society, is not yet finished. The researchers intend to continue calculating the amplitude of the shock wave in the epicenter area under different conditions and the change in the surface temperature of the asteroid along the trajectory, the development in time of the process of the body passing through the atmosphere, including its destruction.