Astronomers infer that the universe is expanding because distant galaxies all appear to
A)be growing in size.
B)be moving away from us,with more distant ones moving faster.
C)be made mostly of dark matter.
D)rotate rapidly.

Question

Quizplus · Accepted Answer

Astronomers have observed that distant galaxies are moving away from us, and the farther away they are, the faster they are moving. This suggests that the universe is expanding.

Astronomers Infer That the Universe Is Expanding Because Distant Galaxies