Canada's University of New Brunswick maintains a database of confirmed impact craters on Earth. So far, it contains 170 sites, but that number is expected to grow as more formations are determined to be impact in origin, and as the sea floor is more thoroughly documented.
Essentially, such a database will contain the newest impact sites, plus perhaps the largest of earlier strikes. That's because Earth's geologic activity eventually erases evidence. Without the volcanism and tectonic plate shifts that constantly renew and rework Earth's surface, our planet would look much like the Moon and Mars.
The database should also serve as a reminder. Earth has been hit numerous times even relatively recently, and will be again unless we develop the space capability to detect and deflect such mountains in the sky.
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