Experts say tens of millions of people around the world have never experienced truly dark skies in their lives, because they live in brilliant urban areas where artificial lights at night keep their communities illuminated.

This may seem inconsequential to the average person, but experts like Richard Green, Ph.D., say the issue is serious.

Green is an astronomer with the Department of Astronomy and Steward Observatory at the University of Arizona.

He said astronomy is a big industry in our region with research facilities, such as Kitt Peak west of Tucson and Mount Graham International Observatory east of the city.

"And so we have a professional and aesthetic interest in keeping the skies as dark as possible," Green said.

Dark Skies Important for Plants, Animals

Dark skies are also important in the biological world, particularly for plants and animals in hot ecosystems like the Sonoran Desert.

Some plants attract night-flying creatures, such as bats or insects for pollination. These animals come out at night to avoid intense summer daytime temperatures and predators.

"They have found another niche if you want to call it to live their lives and the Sonoran Desert is no exception, we have a tremendous diversity of animals ," said Jesus Garcia, education specialist for the Arizona-Sonora Desert Museum.

Dark Skies Book

Professor and author Paul Bogard wrote a book about the importance of dark skies, and scenarios where there wouldn't be any left, as well as possible consequences.

He recently completed "The End of Night: Searching for Natural Darkness in an Age of Artificial Night," and joined AZ Illustrated Nature during a visit to Tucson.

"I wanted to address both the joy and beauty of night and natural darkness and how important it is for us but also the real costs of light pollution," Bogard said.

Green said Arizonans are fortunate in that they still have plenty of dark skies to enjoy in isolated areas, such as the desert west of Tucson.