Question

About how often does a 1-kilometer object strike the earth? about how often does a 1-kilometer object strike the earth? every year every million years every billion years

Answer 1

The correct option is the second one, which is: Every million years.

 The impact of a 1-kilometer object on our planet, would cause significant consequences. As the astronomers have found in other terrestrial bodies, this kind of impact creates largers craters on the surface.