What do astronomers mean by light pollution

Save my name, email, and website in this browser for the next time I comment. About Us. Privacy Policy. Skip to content. What do astronomers mean by light pollution? Examples of Light Pollution Some people only think of streetlights when thinking about light pollution, but the truth is that there is much more than this. Street Lights — The first thing people think of when they image light pollution is street lights.

They are one of the main causes of light pollution. Car Lights — Car Lights are a major cause of light pollution, especially if you consider the build up of lights in big cities. Skyscrapers — You could argue that skyscrapers are necessary, but they are still a cause of light pollution, especially in heavily built up areas. Advertising boards — An example of one that might not actually be necessary is advertising signs and boards.

Do they really need to be illuminated during the night, being a major contributor to light pollution? Types of Light Pollution As well as different sources of light pollution, there are also different types of light pollution that we categorize too. They are; Light Trespass — Like it sounds, this describes when light makes it to an area where it is unwanted.

A good example of this is if you live near built up city area, and the light from skyscrapers or advertising makes it into your flat or condo window — this is light trespass. Skyglow — Most relevant to us as astronomers, Skyglow is the effect of artificial light on our ability to see the sky. With the growth of the city and the use of more and more mercury lamps, Palomar is becoming more and more polluted.

Some Palomar users estimate that if things keep going the way they have been, then in the next ten years or so, Palomar will be useless for deep-sky astronomy. There is still hope for land-based astronomy, though. Palomar is hurt particularly bad by the light pollution problem because of its proximity to the heavily populated areas of southern California. Other telescopes, such as the Keck telescopes in Hawaii are faring extremely well.

There are no bright city lights near these observatories to get in the way of a good night of observing. Some day in the next couple of decades, Palomar may have to be decommissioned like the Mount Wilson telescope near Pasadena in favor of telescopes at more remote sites. Cornell University, for instance, is in the process of building a new telescope far from all civilization in Chile's Atacama Desert. Other telescopes are being built on remote mountaintops, islands, and even the south pole.

Edit by Michael Lam on November 21, : Besides optical telescopes like the ones previously mentioned, radio telescopes suffer the same problem. Instead of optical light sources polluting our view, sources of radio waves, such as cell phones, wireless internet transmitters, GPS satellites, etc. In some cases, they can completely block our ability to observe sources, which is why we try to build radio telescopes in remote locations as well, far away from any interference.

Dave was the founder of Ask an Astronomer. There he runs his own version of Ask the Astronomer. He also helps us out with the odd cosmology question. Home Observational Astronomy Stargazing. How does light pollution affect astronomers?

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Beginner Why is looking out into space the same as looking back in time? Beginner Can we find the place where the Big Bang happened? Most Popular. For many people the sight of the Milky Way stretching across the night sky is a childhood memory; sadly, today a new generation is growing up who have never seen our own galaxy, the place we call home in the Universe. The most obvious everyday manifestation of light pollution is in the increasing illumination of our night sky and the subsequent difficulties in observing astronomical objects from polluted locations.

Light from poorly designed, incorrectly directed light fixtures shines into the sky. The problem of light pollution is not only a menace to astronomers. Light pollution also has numerous direct impacts on the environment. Not only can some high-powered lights produce more carbon dioxide over a year than a modern day diesel car produces in about kilometres, but the strain on wildlife in both urban and rural locations is great. Light pollution is also an unnecessary waste of energy that eventually gets translated into a great and unnecessary cost to economies worldwide.

Light pollution and other such electromagnetic interference from radio waves for example affect not only amateur astronomers, but professionals and their observatories.