The Bortle scale is a way of measuring the quality (brightness) of the night sky for a particular location. There are nine levels to the Bortle scale with Class 9 being the most extreme amount of light pollution.
Class 1: Excellent dark-sky site. The zodiacal light, gegenschein, and zodiacal band are all visible - the zodiacal light to a striking degree, and the zodiacal band spanning the entire sky. Even with direct vision the galaxy M33 is an obvious naked-eye object.
Inner-city sky The level of light pollution in a certain area can be measured on a scale ranging from 1 to 9 which is known as the Bortle scale. Use the slider above to gradually change the image from an inner city skyscape suffering from severe light pollution, to a pristine dark sky site.Welcome to the improved DarkSiteFinder light pollution map. Here are some useful links: - Sortable Dark Site Listing - Add A New Dark Site - How To See the Milky Way - How To See the Aurora - Color Scale Meaning - More Astronomy Links.Try this experiment, and this requires an extremely dark sky with no light pollution. Sorry everyone who lives in a city, you will have to travel a good long distance, and sorry to those living on the east coast of the US or most of Europe, you are going to have to travel for a couple days by car or hours by plane to get skies dark enough. To truly experience this effect you will need to.
Various features of the night sky are assessed to arrive at the Bortle classification. These include the visibility of various celestial objects and phenomena as well as the level of cloud illumination and the presence of light pollution domes. Again these are carried out at key sites as with the methods above. The Bortle scale runs from 1 to 9.Read More
Bortle Ratings The Bortle Scale rates how well you can see celestial objects in a certain place, taking into account light pollution and sky glow. Lower numbers indicate darker skies. For example, Big Bend Ranch State Park has a Bortle Scale rating of 1, while Cedar Hill State Park, near Dallas, has a Bortle rating of 8. Below is a list of all state parks, by region, with Bortle Scale ratings.Read More
Since the introduction of electric lighting over a century ago, and particularly in the decades following the Second World War, indications of artificial light on the nighttime Earth as seen from Earth orbit have increased at a rate exceeding that of world population growth during the same period. Modification of the natural photic environment at night is a clear and imminent consequence of.Read More
In addition to the recognition of Newport’s dark skies, the designation of Dark Sky Park accompanies a commitment by Newport to be a figure for night sky education and awareness in the Door County community, with Newport offering at least four programs a year of public education and involvement through night sky activities as well as general public outreach.Read More
The Dark Sky Project is a response to the National Park Service’s Call to Action. Under the sponsorship of Acadia National Park, the team focused on point 27, “Starry, Starry Night.” The point focuses on natural darkness, classifying it as a natural resource. It calls for the preservation of a natural dark sky, in an effort to restrain man-made light from intruding on such. College of.Read More
The Bortle Dark-Sky Scale was begun by amateur astronomers in 2001, but is now used as a universal standard for light pollution. Finding a truly dark-sky site, ranking a 1 or 2 on the Bortle scale.Read More
The Bortle Dark-Sky Scale is a nine-level numeric scale that measures the night sky's and stars ' brightness (naked-eye and stellar limiting magnitude) of a particular location. It quantifies the observability of celestial objects (significant naturally occurring physical entities, associations or structures which current science has demonstrated to exist in outer space) and the interference.Read More
Bortle Classification Bortle classification is more subjective than the above methods, but is still a widely recognised means of evaluating light pollution. Various features of the night sky are assessed to arrive at the Bortle classification. These include the visibility of various celestial objects and phenomena as well as the level of cloud illumination and the presence of light pollution.Read More
International Dark Sky Places. The UK has some of the largest areas of dark sky in Europe. You can find dark skies near where you live, if you can get away from bright lights such as street lighting. That could be in your back garden, a local park, or getting out of town altogether. From a city centre location we might see about 100 stars with our naked eyes, and the further away from the.Read More
The Bortle Scale was originally created and published by John E. Bortle in an article in Sky and Telescope magazine in February, 2001. The Bortle scale is based on nine classes of dark sky, with Class 1 being the best, or black on the atlas maps, and Class 9 or white on the atlas maps.Read More