Final answer:
Astronomers use infrared and radio telescopes to observe protostars, which radiate in the infrared spectrum and can be obscured by dust and gas. Observations in this spectrum can be made from ground-based facilities or space, avoiding atmospheric interference that affects other wavelengths.
Step-by-step explanation:
To observe protostars, which are at low temperatures and obscured by dust and gas, astronomers must use infrared and radio telescopes. These types of telescopes are able to detect the emissions from the dust particles heated by the protostar, which mostly radiate in the infrared spectrum. Furthermore, since the Earth's atmosphere blocks most radiation at wavelengths shorter than visible light, such as ultraviolet, X-ray, and gamma rays, observations in these wavebands need to be conducted from above the atmosphere. This makes infrared and radio astronomy feasible from ground-based facilities on dry mountain peaks or from telescopes aboard aircraft and in space, circumventing atmospheric interference and allowing for clearer detection of celestial objects like protostars.