The largest observatory complex in the world is on Mauna Kea, the tallest mountain on Earth. What are some factors astronomers consider when selecting an observatory site? Don’t forget practical ones. Should astronomers, for example, consider building an observatory on Denali (Mount McKinley) or Mount Everest?

When selecting a site for an observatory, astronomers consider several factors:

1. Altitude: The higher the altitude, the less atmosphere there is to distort the light from the stars. This is why Mauna Kea, despite not being the highest peak above sea level, is considered the tallest mountain from base to peak and is an ideal location for an observatory.

2. Climate: Dry climates are preferable because humidity and precipitation can interfere with observations.

3. Light Pollution: Areas with low light pollution are ideal as artificial light can interfere with the ability to observe faint celestial bodies.

4. Stable Ground: The ground needs to be stable, not prone to earthquakes or landslides, as these could damage the observatory.

5. Accessibility: The site needs to be accessible for construction, maintenance, and for astronomers to reach. It also needs to have the infrastructure to support the observatory, including roads and electricity.

Considering these factors, building an observatory on Denali or Mount Everest would be challenging. While they have the advantage of high altitude, they also have severe weather conditions, and accessibility would be a significant issue. The infrastructure costs would likely be prohibitive, and the risk to construction and maintenance crews would be high. Therefore, while not impossible, it's unlikely that these locations would be chosen for a new observatory.