Mountain tops are great locations for building observatories. Astronomers need clear skies in order to observe the stars and cosmos. Observatories at a higher elevation are above a certain level of atmosphere. Sometimes clouds interfere with telescope viewing and images. High mountain tops are above the clouds and provide clean, dry, and less turbulent air. There is less water vapor at a higher elevation, minimizing the light distortion or twinkling of the stars. When selecting a site for a mountain top observatory, there are some important factors that must be considered. As mentioned earlier altitude and dry climate are necessary for clean images and observing. Light pollution is the excessive use of artificial lighting. When this light is inefficiently used, it creates a sky glow that prevents astronomers from clearly viewing the sky. It is important to pick a location that is far from urban cities and relatively free of artificial light.
The installation of the world’s largest telescope in Hawaii has been debated for years. Officials argue that Mauna Kea is the ideal location for this project. Building the telescope on this site is extremely controversial and is not supported by Native Hawaiians as they consider Mauna Kea sacred and have protested to prevent the project from going forward. The backup location for the telescope is on a mountain top in La Palma, part of the Spanish Canary Islands. The cost of operating a telescope in Spain would be much lower as the peak is at a lower elevation. There is a greater public agreement for the telescope to be built there. However, there are environmental organizations that have opposed the TMT and have successfully managed to delay the building permit. The area claimed by TMT is a conservation site containing important archaeological artifacts. While many officials agree that La Palma is an ideal backup location, astronomers disagree.
Astronomers argue that the telescope will not be high above the atmosphere making it harder to view the galaxies and exoplanets. Dry conditions will not be as frequent compromising the view of galaxies and planets whose lights have shifted wavelengths due to the expansion of the universe. The Gran Telescopio Canarias, currently the world’s largest telescope is located on this site and has successfully aided observations and produced images even in the mid-infrared. Despite all the advantages and the cost-benefit analysis, astronomers and officials still remain disputed about the location of the telescope. There are many environmental and geopolitical factors affecting this project. The TMT can revolutionize astronomical research, but at what cost?