The record of collision of the Earth with extraterrestrial bodies is far from complete because huge areas have not yet been properly surveyed. Search for the evidence of impact is not an easy task, however, because many impact structures have been erased by geological processes [e.g., Grieve, 1997] . As a result, only a few impact structures are known so far in Northeast and Central Asia (Figure 1) [Grieve, 1997semi; Earth Impact Database, 2002].
If you can't find a tool you're looking for, please click the link at the top of the page to "Go to old article view". Alternatively, view our Knowledge Base articles for additional help. Your feedback is important to us, so please let us know if you have comments or ideas for improvement.