What was the largest asteroid to ever hit Earth?
Impact event
The Moon's existence is widely attributed to a huge impact early in Earth's history.[29] Impact events earlier in the history of Earth have been credited with creative as well as destructive events; it has been proposed that impacting comets delivered the Earth's water, and some have suggested that the origins of life may have been influenced by impacting objects by bringing organic chemicals or lifeforms to the Earth's surface, a theory known as exogenesis.