Coordinates: 49°05′28″N122°08′02″W / 49.091°N 122.134°W
A geographic coordinate system is a coordinate system that enables every location on Earth to be specified by a set of numbers, letters or symbols. The coordinates are often chosen such that one of the numbers represents a vertical position and two or three of the numbers represent a horizontal position; alternatively, a geographic position may be expressed in a combined three-dimensional Cartesian vector. A common choice of coordinates is latitude, longitude and elevation. To specify a location on a plane requires a map projection.
McDonald Park, in Abbotsford, British Columbia, Canada, is a dark-sky preserve, [1] designated thus by the Royal Astronomical Society of Canada. [2]
Abbotsford is a city located in British Columbia, adjacent to the Canada–United States border, Greater Vancouver and the Fraser River. With an estimated population of 141,397 people it is the largest municipality in the province outside Metro Vancouver. Abbotsford-Mission has the third highest proportion of visible minorities among census metropolitan areas in Canada, after the Greater Toronto Area and the Greater Vancouver CMA. It is home to Tradex, the University of the Fraser Valley, and Abbotsford International Airport.
A dark-sky preserve (DSP) is an area, usually surrounding a park or observatory, that restricts artificial light pollution. The purpose of a dark sky preserve is generally to promote astronomy. Because different national organizations have worked independently to create their programs, different terms have been used to describe the areas. This has led to confusion between the terms reserve, preserve, and park. The International Dark-Sky Association (IDA) chooses reserve to avoid confusion with park, when using the initialisms "IDSR" and "IDSP".
The Royal Astronomical Society of Canada (RASC) is a national, non-profit, charitable organization devoted to the advancement of astronomy and related sciences. At present, there are 28 local branches of the Society, called Centres, in towns and cities across the country from St. John's, Newfoundland, to Victoria, British Columbia, and as far north as Whitehorse, Yukon. There are about 5100 members from coast to coast to coast, and internationally. The membership is composed primarily of amateur astronomers and also includes numerous professional astronomers and astronomy educators. The RASC is the Canadian equivalent of the British Astronomical Association.
The park is located in a valley, and at night light pollution from the nearby cities of Abbotsford, Chilliwack, and Mission is blocked by Sumas Mountain. [2] The park opens at night for observations under the auspices of the Fraser Valley Astronomers Society. [3]
Light pollution, also known as photopollution, is the presence of anthropogenic light in the night environment. It is exacerbated by excessive, misdirected or obtrusive uses of light, but even carefully used light fundamentally alters natural conditions. As a major side-effect of urbanization, it is blamed for compromising health, disrupting ecosystems and spoiling aesthetic environments.
Chilliwack is the 7th largest agglomeration in British Columbia, Canada. Historically an agricultural community, most of its 83,788 residents are now city-dwellers. Chilliwack is the seat of the Fraser Valley Regional District and its second largest city. This city is surrounded by mountains and recreational areas such as Cultus Lake and Chilliwack Lake Provincial Parks. It is located 102 kilometres southeast of Vancouver. There are many outdoor activities in the area, including hiking, horseback riding, archery, biking, camping, fishing, and golf.
Mission is a district municipality in the Lower Mainland of the province of British Columbia, Canada. It was incorporated as a district municipality in 1892, growing to include additional villages and rural areas over the years, adding the original Town of Mission City, long an independent core of the region, in 1969.
