Protostars are difficult to observe because
A)the protostar stage is very short.
B)they are surrounded by cocoons of gas and dust.
C)they radiate mainly in the infrared.
D)the protostar stage is very short, they are surrounded by cocoons of gas and dust, and they radiate mainly in the infrared.
E)they are all so far away that the light hasn't reached us yet.

Question

Quizplus · Accepted Answer

Protostars are difficult to observe for multiple reasons. The protostar stage is short, so it is not easy to catch them in that stage. Additionally, they are often surrounded by cocoons of gas and dust that can obscure them from view. Finally, protostars radiate mainly in the infrared, which makes them difficult to observe with traditional telescopes that can only detect visible light. Therefore, choice D, which includes all of these reasons, is the best answer.

Protostars Are Difficult to Observe Because