How can molecular clouds be observed?
A)by using infrared telescopes to detect ionized gas in the clouds
B)by using X-ray telescopes to observe the X-ray radiation from the molecules in the cloud
C)by using radio telescopes to observe the emission from CO molecules in the clouds
D)by using radio telescopes to observe the 21-cm radiation from hydrogen

Question

Quizplus · Accepted Answer

Molecular clouds are often observed using radio telescopes to detect emissions from CO molecules, which are abundant and emit strongly in the radio spectrum.

How Can Molecular Clouds Be Observed