You must be able to see the stars if you have an observatory. Mirrors are overcoated with transparent coating which is vulnerable to acid. If acid falls on mirror overnight, will deteriorate, mirrors will have to be recoated and increase operating costs. Willing to operate atmospheric monitoring stations at the observatory. Best season winter.
Summers are the worst, prevailing winds from the Southeast.
Miguel Flores National Park Service Visibility degradation problem not only at Big Bend, Blue Bridge Parkway in Virginia. Mexico is the latest culprit - this is nothing new. NP scientists estimate that Carbon 1 and 2 will emit 250,00 tons of sulfur dioxide to atmosphere per year. Until 1977 U.S. clean air act outlined protection for national parks. 48 Class 1 areas designated - including Big Bend and Guadalupe Mountains.