Dendrochronology is applied to the examination of survived trees of cosmic bodies impact, as in the two sites of Tunguska and Sikhote-Alin in Russia. In the area of Tunguska in 1908 was damaged an area of approximately 2000 square kilometres of forest (fig. 1), with dendrochronology were examined survived plants near Lake Cheko, originated from the impact of a cosmic fragment (fig. 2).