This resulted in the insertion into Earth orbit of vaporized material from the impactor and the Earth, which condensed and accreted to form the moon. Heat generated by early impacts may have led to outgassing of Earth's initial crust, thus, contributing to the primordial atmosphere and hydrosphere. Additionally, the impacting bodies themselves, may have contributed to the Earth's budget of volatiles. This early bombardment would also have frustrated the development and evolution of early life, with the largest impacts having the capacity to effectively sterilize the surface of the globe. In more recent geologic time, there is evidence that at least one mass extinction event, notably that of the dinosaurs and many other species 65 million years ago, is linked to global effects caused by a major impact event.
Impacts also have some economic significance.
Most of the terrestrial impact craters that ever formed, however, have been obliterated by other terrestrial geological processes. Some examples, however remain. To-date, approximately 150 impact craters have been identified on Earth. Almost all known craters have been recognized since 1950 and several new structures are found each year. The morphology of impact craters changes with crater diameter.