Killer asteroids



Killer asteroids is a generic term for celestial bodies that collide with Earth and are large enough that the collision's effects lead to a mass extinction event. The most famous example is the 10-kilometer-wide asteroid whose impact is generally believed to have been the primary cause of the Fifth Great Extinction 65 million years ago. Other celestial bodies that have caused mass extinctions may actually have been comets, not asteroids; nevertheless, the term "killer asteroid" is probably the most common descriptor for these objects among non-scientists.