As of April 2019[update], the database lists 190 confirmed impact sites.[1]
Other lists are wider in scope by including more than just confirmed sites, such as probable, possible, suspected and rejected or discredited impact sites on their lists. These are used for screening and tracking study of possible impact sites. Sites will appear first in these lists while under study and may be incorporated into UNB's Earth Impact Database after confirmation and collection of enough information about the site to satisfy the database's strict entry criteria.[2]
A previous list was maintained by the Impact Field Studies Group at the University of Tennessee, Knoxville. The Catalogue of the Earth's Impact structures is maintained at the Siberian Center for Global Catastrophes.[3]