The 1908 Tunguska event is unique because it was observed by numerous local residents. In addition, the surroundings of the epicenter were carefully studied by numerous expeditions. This allows us to single out the following features of the interaction of a cosmic body with the atmosphere: (1) the head of the flying object was ≥2 ​km in size; (2) the flight was accompanied by sounds similar to firing from a machine gun; (3) near the epicenter, the object was moving at a speed of <3 ​km ​s⁻¹. To explain these features, a model of the cometary nucleus is proposed, and the fragmentation of the comet in the atmosphere is considered. It is assumed that the cometary nucleus is a multi-layered porous structure consisting of granules weakly connected to each other. The layers are separated by gas-tight shells. The fragmentation of such structure is closely connected with the sublimation of water and volatiles. A rapid phase transition from a solid to a gaseous body releases and throws out grains with refractory components. This explosive release of matter results in flares and loss of kinetic energy by the object. The calculations shown that under certain conditions, the Tunguska cosmic body with a mass of (3–4) ·10⁹ ​kg could slow down and approach the Earth’s surface, retaining half of the original mass.

1908年通古斯（Tunguska）事件之所以独一无二，是因为它被众多当地居民所观察到。此外，震中的周围环境也经过众多探险队的仔细研究。这使我们能够选择出宇宙物体与大气相互作用的以下特征：（1）飞行物体的头部尺寸≥2km; （2）飞行中伴随着类似于机枪射击的声音；（3）在震中附近，物体以<3 km s ^-1的速度运动。为了解释这些特征，提出了彗星核的模型，并考虑了彗星在大气中的破碎。假定彗核是由彼此弱连接的颗粒组成的多层多孔结构。各层由气密壳隔开。这种结构的破碎与水和挥发物的升华紧密相关。从固态到气态的快速相变会释放出并抛出具有耐火成分的晶粒。物质的爆炸性释放会导致耀斑和物体失去动能。计算表明，在一定条件下，通古斯（Tunguska）宇宙物体的质量为（3–4）·10 ⁹ 公斤可能会减慢并接近地球表面，保留原始质量的一半。