When was the last time you saw the night sky revealed, with its full array of stars? Some New Mexicans living in remote areas can see the cosmos in all their glory every night, clouds permitting. But those living in population centers, including many small towns, cannot, due to artificial lighting.
Unlike many states, New Mexico has a state law limiting light pollution. However, Jon Holtzman, an astronomy professor emeritus at New Mexico State University, said that the is due for an update, thanks to changes in light-bulb technology. More on that in a bit.
Holzman spends some of his personal time working for , an organization focused on preserving the world鈥檚 unspoiled night skies.
鈥淥nly a small fraction of the U.S. population lives somewhere where they can even see the Milky Way, so people don't even know what it is,鈥� Holtzman said. 鈥淎nd people are starting to come to darker locations for a new kind of tourism called astro-tourism, and New Mexico is a good destination for that. So it actually brings in some economic impact by preserving our dark skies.鈥�
However, tourist dollars are far from the most compelling reason to protect dark skies. The unblemished night skies are important for . Holtzman said humans benefit, as well.
鈥淭here's some suggestion that light pollution affects ,鈥� Holtzman said. 鈥淎nd then there's also the simple argument of energy and money. Putting light up in the sky where it's not used wastes energy and costs extra money.鈥�
DarkSky advocates for lighting to go only where it鈥檚 useful or necessary.
鈥淚 think it's important to state up front that the goal of organizations like DarkSky is not to have everyone turn out all their lights,鈥� Holtzman said. 鈥淚t's to do what we call responsible lighting. So when lights are installed, the light shines on the ground where it's needed, and not up in the sky where it just does no one any good and it does a lot of harm.鈥�
has been an active chapter of the international organization since June 2023. But that state鈥檚 legislation protecting dark skies was written when incandescent lighting was the norm.
鈥淣ow the predominant type of lighting is LED lighting,鈥� Holtzman said. 鈥淎nd people used to talk about how bright lights were in terms of watts, which is a measurement of energy, not a measurement of brightness.鈥�
Energy-efficient LED lighting uses fewer watts, so intensely bright lights can fall well within the now-archaic wattage restrictions. New Mexico DarkSky seeks to get the New Mexico statute to limit lumens, rather than watts.
Although DarkSky does lobby for legislation, the organization鈥檚 main focus is education and outreach among the general public, Holzman said. DarkSky offers , businesses and public agencies looking to make their lighting more night-sky friendly.
鈥淭he basic principle is, use shielded lighting outside, so that you're basically ensuring that any light fixtures that you put up don't put any light up in the sky and don't put any light into your neighbor's yards,鈥� Holtzman said.
鈥淪ometimes excessively bright light can create excessively dark shadows, which people can go unseen on and if you're looking outside, or law enforcement is looking outside, bright lights can actually blind you, in a process we call glare 鈥� it's hard to see an intruder when there's extra glare,鈥� Holtzman said. 鈥淪o responsible lighting can actually be safer.鈥�
For domestic needs, Holtzman recommends setting outdoor lights to motion sensors, when possible and where appropriate.
New Mexico DarkSky has joined with several public and private entities to form the , a collaborative effort to preserve dark skies in the vicinity of Carlsbad Caverns National Park in the state鈥檚 southeast, and Chaco Culture National Heritage Park in northwestern New Mexico.
In Carlsbad earlier this year, Denver-based Franklin Mountain Energy retrofitted a , with the result of a 99 percent reduction in skyglow, or the appearance of brightness in the night sky. The changes also reduced the lighting system鈥檚 electricity consumption by 60 percent, the company said.
Light-pollution mapping projects, such as published by University of Wisconsin researcher David Lorenz, show the dramatic effects of oil and gas production on night skies in the Permian Basin.
DarkSky also has a program for establishing recognized dark sky locations, with varying certifications for different types of sites. certified dark-sky locations, including the Gila National Forest鈥檚 , the only site in North America to earn the DarkSky International鈥檚 highest ranking, that of International Dark Sky Sanctuary.
In addition to conservation and awareness, Holtzman also recommends just enjoying the beauty of a truly dark New Mexico sky, if you haven鈥檛 done so recently -- or ever.
鈥淣ew Mexicans are lucky, and we should realize it,鈥� Holtzman said. 鈥淎 lot of people in this country don't have what we have, so we should appreciate it, and we should preserve it.鈥�
