Dark-Sky Site Guidelines

RASC Dark-Sky Program

Presented by the RASC LPAC

On March 30, 2008, the RASC adopted a Dark-Sky Program that includes Dark-Sky Preserves™ (DSPs), Urban Star Parks (USPs) and Nocturnal Preserves (NPs).  These three designations reflect the benefit for outreach programs of readily accessible sites within or near urban areas and more remote dark sites for observing the pristine sky.

The documents located on the left side bar introduce Urban Star Parks and Dark-Sky Preserves and Nocturnal Preserves. Let these documents be your guide. The contents of these documents (initial version) have been adopted in 2008 by Parks Canada as their "Best Practice" in all federal park facilities.

The RASC Light-Pollution Abatement Committee wish to encourage every RASC Centre, and other groups and organizations to seek out dark sites and local urban areas that can be used for public star nights, or that with some improvements, may become suitable.  These properties may be any defined area under the control of management, such as federal or provincial parks or private parks and campgrounds.

The key components of the RASC Dark-Sky Program are:

  • control of local lighting,
  • outreach programs aimed at the general public and neighbouring municipalities,
  • and to demonstrate good nighttime lighting practices.

The following information introduces the contents of these documents.

Glare vs Sky Glow

A USP with Controlled Lighting                        A Dark Site with No Control of Lighting


Two files contain the management guidelines for the USP and DSP. Local sponsorship is required to document the proposed site and to assist park managers and their staff with astronomy and light-pollution abatement outreach programs. The benefit for the local astronomy group is the long-term protection of their observing site and assistance in the promotion of astronomy. An additional spin-off is better public and political understanding of the problems of light pollution and the benefits in its reduction. This lasting legacy is perhaps the most important benefit of this program.

The above files also contain Guidelines for Outdoor Lighting (GOL) for USPs and DSPs. These Guidelines define the attributes of Low-Impact Lighting (LIL). They suggest design solutions that will enable the restriction of lighting within the protected sites. Although we do not propose a prohibition on light, this program does require that any light must be justified on a case-by-case basis. Thus a pristine area should remain without artificial lighting and illuminated areas will have minimal impact on the ecology and visibility of the night sky in the area. This is significantly different from rationalizing the reduction of illumination levels from generally urban levels.


Dark Sky Site
Urban Star Park


Although the designation of USP, DSP or NP is made by the RASC, it is up to the judgment of the sponsoring group whether a local site should be considered for a USP, DSP or NP designation. So, we ask that Centres of the RASC, and any other interested group or organization (astronomy, environmental and conservation groups, land managers, municipalities and other government agencies) to propose USPs, DSPs and NPs in their regions.

Images © R.Dick, used with permission

Last modified: 
Monday, November 19, 2018 - 2:05pm