A dark-sky preserve (DSP) is an area, usually surrounding a park or observatory, that restricts or reduces light pollution or maintains and protects naturally dark night skies. Different terms have been used to describe these areas as national organizations and governments have worked independently to create programs. DarkSky International (DarkSky) uses "International Dark Sky Reserve" (IDSR) and "International Dark Sky Park" (IDSP) among others when certifying Dark Sky Places.

History

DarkSky International was founded in 1988 to reserve public or private land for an exquisite outlook of nocturnal territories and starry night skies. Dark-sky preserves are specifically conserved for their cultural, scientific, natural, or educational value and public enjoyment. In 2007, the Mont Mégantic Observatory in Quebec was the first site to be certified as an International Dark Sky Reserve by DarkSky. The same year, Natural Bridges National Monument in Utah became the first International Dark Sky Park. The Gabriela Mistral Dark Sky Sanctuary in the Elqui Valley of Chile was designated as the world's first International Dark Sky Sanctuary in 2015. A dark-sky preserve, or dark-sky reserve, should be sufficiently dark to promote astronomy. The lighting protocol for a dark-sky preserve is based on the sensitivity of wildlife to artificial light at night. Canada has established an extensive and stringent standard for dark-sky preserves, that addresses lighting within dark-sky preserves and influences from skyglow from urban areas in the region. This was based on the work of the Royal Astronomical Society of Canada.

Dark Sky Places

DarkSky International's Dark Sky Places program currently offers five types of designations: Dark Sky Developments of Distinction recognize subdivisions, master planned communities, and unincorporated neighborhoods and townships whose planning actively promotes a more natural night sky but does not qualify them for the International Dark Sky Community designation. This designation was retired in 2020. Further designations include "Dark Sky Nation", given to the Kaibab Indian Reservation, and "Parashant International Night Sky Province-Window to the Cosmos", given to Grand Canyon-Parashant National Monument.

Dark sky preserves, reserves, and parks

As of January 2023, there are 201 certified Dark Sky Places globally: 38 Communities, 115 Parks, 20 Reserves, 16 Sanctuaries, 6 Developments of Distinction and 6 Urban Night Sky Places.

Protected zones

Around observatories

Other

Some regions, like the following, are protected without any reference to an observatory or a park.

By country

Canada

In the Canadian program, lighting within the area must be strictly controlled to minimize the impact of artificial lighting on wildlife. These guidelines are more stringent than in other countries that lack the extensive wilderness areas that still exist in Canada. The management of a Canadian DSP extends their outreach programs from the public that visit the site to include the promotion of better lighting policies in surrounding urban areas. Currently, dark-sky preserves have more control over internal and external lighting than other programs. With the increase in regional light pollution, some observatories have actively worked with cities in their region to establish protection zones where there is controlled light pollution. These areas may not yet have been declared dark-sky preserves. Although dark-sky preserve designations are generally sought by astronomers, it is clear that preserving natural darkness has positive effects on the health of nocturnal wildlife within the parks. For example, the nocturnal black-footed ferret was reintroduced to the Grasslands National Park dark-sky preserve and the success of the reintroduction is enhanced by the pristine natural darkness maintained within the park by the DSP agreement.