Clouds that appear dark in visible light often glow when observed at long infrared wavelengths.

Question

Quizplus · Accepted Answer

This is true. Dark clouds may appear to block all visible light, but they can still emit radiation at longer infrared wavelengths, giving them a faint glow that is visible to infrared telescopes. This is because dark clouds are still warm, and all objects with a temperature above absolute zero emit radiation at longer wavelengths.

Clouds That Appear Dark in Visible Light Often Glow When