Natural darkness and starry night skies are important natural resources. And just like the Florida panther or spotted owl, night skies are endangered. With El Morro 40-50 miles from the closest cities, the night skies are clear, dark, and dramatic. However, local industrial development and increased rural settlement has begun to introduce "light pollution," stray light from buildings and vehicles that reflects down from the atmosphere and obscures our delicate celestial scenery.
Night Sky Monitoring
To track changes in night sky darkness, special cameras are used by park scientists to precisely measure light pollution coming from urban areas. For example,this black-and-white image taken from El Malpais National Monument, just east of El Morro, shows the dull glow of Grants and Albuqureque on the horizon.
When analyzed by a computer, an exact level of brightness can be calculated for this image, and is shown below in a rainbow of colors. This allows the light levels from one photograph to be easily compared to another photograph at another location, or taken another year.
Here you can clearly see the light pollution, in white-to-red-to-yelllow, from the two cities.
You Can Help!
Next time you turn on your lights at home, visit a store to shop after dark, or come to a remote place like El Morro and look at the night sky, think about how much light is escaping into the night sky and blocking out the stars. There are many things you can do to reduce light pollution, and a great place to start is: http://nature.nps.gov/night/
Did You Know?
It is estimated that the mesa-top pueblo at El Morro National Monument contained about 875 rooms. However to see it is deceiving—only a small corner of the pueblo was ever excavated.