Author Question: On average, how often do impactors about 10 km in size, large enough to produce mass extinction, hit ... (Read 108 times)

Mr. Wonderful · **on:** Jul 27, 2018

On average, how often do impactors about 10 km in size, large enough to produce mass extinction, hit Earth?

A) once every century
B) once every thousand years
C) once every million years
D) once every hundred million years
E) once in Earth's history

Question 2

Visible sunspots lie in the

A) chromosphere.
B) transition zone.
C) corona.
D) radiative zone.
E) granulation in the photosphere.