Valley of Stone and Sky

Brian Koberlein

Santiago is bounded by ocean and mountains. What’s amazing to see is just how large, rugged and close the mountains are to downtown. When walking among the city buildings, you’ll catch a glimpse of the mountains that seem to hold Santiago in a valley of stone and sky. While this makes for stunning views, it also makes for a region of ideal observing conditions.

For one, the combination mountains and ocean means that the air mass around the region is quite stable. Turbulent air motion is bad for astronomy, as it can cause distortions of observed images. Since much of the urban development is hemmed in by the mountains, the amount of light pollution in the region is minimal. This, combined with the skilled workforce necessary for telescope construction makes Chile extremely well suited for astronomy, as we’ll see.