Striking a balance
At the Xinglong Observatory in Hebei province, researchers have witnessed the impact of man-made lighting on night skies.
"Artificial lighting from surrounding towns has gradually increased the brightness of the night sky, directly reducing the efficiency of telescope observations," said Fan Zhou, a researcher at the National Astronomical Observatories of the Chinese Academy of Sciences.
"Many faint celestial objects and deep-sky survey targets are becoming increasingly difficult to observe."
In March 2025, observatories introduced a standard that classified dark sky environments into five levels based on measured sky brightness. The system provides a common scientific reference for assessing astronomical observation sites, nature reserves and stargazing destinations.
However, Fan cautioned standards are only "scientific tools".
"Dark sky conservation requires coordination among many different parties. Technical standards alone are far from enough," he said.
Fan called for stronger local regulations, long-term monitoring and cooperation among authorities, communities and tourism operators. At Xinglong, researchers regularly monitor sky brightness and communicate with local authorities about changes in surrounding lighting.
Ruskin Hartley, executive director and CEO of DarkSky International, has been following the growing popularity of astrotourism around the world.
"We want people to experience dark skies and the wonder and awe they inspire. But as with any tourism, growth needs to happen responsibly or we risk damaging the very thing people are traveling to experience," he said.
The challenge can begin with something as ordinary as a hotel or guesthouse. "Even a single accommodation that does not consider how it lights the night can have a significant impact on the surrounding environment," Hartley said.
In 2024, DarkSky International released its Principles of Responsible Astrotourism to help destinations and tourism businesses incorporate protection of the nighttime environment into their development plans.
Hartley cited the example of Moab, Utah, in the United States, where visitors come for its red rock canyons, natural arches and outdoor recreation. As tourism has expanded, so have hotels, resorts and other facilities.
In 2024, the community received International Dark Sky Community certification and subsequently adopted outdoor lighting standards to protect its night skies.
"The lesson for emerging destinations in China is that protection does not have to come at the expense of tourism or development," Hartley said.
zhengjinran@chinadaily.com.cn
