Why are ground observatories often built in extremely dry regions like deserts?
Answer
To minimize water vapor absorption of infrared light.
Dry locations are crucial because water vapor in the atmosphere strongly absorbs many critical infrared wavelengths, hindering ground-based infrared astronomy.

Related Questions
What is the fundamental challenge facing ground-based telescopes?What causes the phenomenon known as 'astronomical seeing'?How much can atmospheric seeing typically degrade the practical resolution of a massive ground telescope?Despite ruining sharpness, what capability of a large ground mirror is unaffected by atmospheric distortion?Which type of high-energy radiation emitted by celestial objects is completely absorbed by the atmosphere, necessitating space observation?Why are ground observatories often built in extremely dry regions like deserts?Besides atmospheric effects, what ground-based interference drastically reduces the contrast of faint astronomical sources?What practical constraint currently prevents launching primary mirrors 20-meters in size into orbit?What key long-term advantage do ground-based telescopes possess over space telescopes positioned at locations like L2?What specific component is used in an Adaptive Optics system to reverse atmospheric light distortion in real-time?