Question

How does the interstellar medium obscure our view of most of the galaxy in visible light?

A) The small mixture of dust grains in the interstellar medium absorbs visible light.

B) Dust reflects most light from distant regions of the galaxy back towards the source.

C) Hydrogen gas produces so much visible light that the interstellar medium is opaque, blocking our view
of anything beyond it.

D) Molecules in the interstellar medium absorb all wavelengths of light.

E) all of the above

Answer 1

The interstellar medium obscures our view of most of the galaxy in visible light due to the presence of interstellar dust, which absorbs and scatters visible light. Astronomers can overcome this limitation by observing in the infrared portion of the spectrum.

Step-by-step explanation:

The interstellar medium obscures our view of most of the galaxy in visible light primarily due to the presence of interstellar dust. These dust grains act as tiny solid particles that absorb and scatter visible light, making it difficult for us to see distant regions of the galaxy. The absorption and scattering of light by interstellar dust is more pronounced at shorter wavelengths, such as in the visible region, compared to longer wavelengths.

One way astronomers overcome this limitation is by observing in the infrared portion of the spectrum, where the obscuration due to interstellar dust is significantly reduced. Infrared light, with longer wavelengths, can penetrate through the interstellar medium more efficiently, allowing us to study stars and structures that are located farther away.