30亿年以来,“天外来客”陨石在地球上砸成的直径大于0.8公里的陨石坑达15万个以上,其中直径超过10公里的3000多个,而直径为30公里或更大一些的陨坑为200个左右。至今,在地球表面已识别出的陨石冲击坑有130个之多,其年龄自20亿年到近代不等。在这130个陨坑中,有地表显示和隐埋于地下的差不多各占一半,绝大多数发现于 For more than 300 million years, more than 150,000 craters of more than 0.8 km in diameter have been smashed into the earth by more than 3,000 craters of more than 10 kilometers in diameter and 30 kilometers in diameter or more The crater is about 200. To date, there have been as many as 130 meteoric impact craters identified on the Earth’s surface, ranging in age from 2 billion years to modern times. In these 130 craters, there are almost half of the surface display and buried in the ground, the vast majority found in