* Molecular clouds are cold and dense: They have temperatures of around 10-100 Kelvin (-441 to -279 degrees Fahrenheit). At these temperatures, molecules don't emit much visible light.
* Dust obscures visible light: Molecular clouds are full of dust particles, which block visible light. This makes them appear dark in visible wavelengths.
* Infrared light penetrates dust: Infrared radiation has longer wavelengths than visible light and can penetrate dust more easily. This allows us to see through the dust and observe the stars and molecules inside the cloud.
* Radio waves are emitted by molecules: Molecules within the cloud emit radio waves at specific frequencies. By studying these radio emissions, astronomers can identify different molecules present in the cloud and understand their chemical composition.
Therefore, using infrared and radio telescopes are the best ways to observe and study molecular clouds.
