This is a fascinating visualization by the B612 Foundation of how common asteroid impacts of >1KT are on the Earth today. Spoiler alert: there were 26 such impacts between 2000-2013, most of them occurring over the oceans.
This visualization is based on research by Peter Brown who published a study in the 14 November 2013 edition of Nature suggesting the potential risk of smaller asteroids in the 10-50 meter range had been underestimated.
The research method is clever here–essentially reanalyzing data collected by the global network of recording stations operated by the Comprehensive Nuclear Test Ban Treaty Organization. Extremely large explosions in that data that are known not be nuclear tests are almost certainly the result of asteroid collisions with our planet.