The average density of the interstellar medium is
A) much denser than Earth's atmosphere.
B) much less dense than the best vacuum on Earth.
C) about the same density as air on the peak of Mount Everest.
D) zero.
E) about as dense as Earth's atmosphere at sea level.

Question

Quizplus · Accepted Answer

The interstellar medium is extremely sparse, with densities much lower than any vacuum we can create on Earth, making it much less dense than even the best vacuum on Earth.

The Average Density of the Interstellar Medium Is