Question

We know our galaxy has a lot of dark matter surrounding it because

A. The rotation of the galaxy requires more mass than can be seen in the form of stars and gas.
B. We can see it directly using telescopes.
C. It interacts with light in a way that we can measure.
D. It is the only way to explain the formation of galaxies.

Answer 1

Dark matter is inferred from its gravitational effects on visible matter, and the rotation of galaxies requires more mass than can be seen in the form of stars and gas.

Step-by-step explanation:

Our galaxy, as well as other galaxies, contains a significant amount of dark matter surrounding it. Dark matter cannot currently be observed directly with telescopes, but its existence is inferred from the gravitational effects it exerts on visible matter. One piece of evidence for the presence of dark matter is the rotation of the galaxy. The rotation requires more mass than can be accounted for by the visible stars and gas. Therefore, option A, 'The rotation of the galaxy requires more mass than can be seen in the form of stars and gas,' is the correct answer.