Question:What evidence is there for life on Earth being threatened in the past by Asteroid collision?
Most of our knowledge of life on Earth in the past comes from studying the Fossil Record.
The Fossil Record is the collection of known fossils.
It has been found that a various times in the past, there was a sudden change in the number of species.
Fossils of various creatures just stop appearing in the fossil record.
Asteroid impacts have been traced to some of these same time periods.