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Globe at night - light pollution

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Participate in Night Sky Measurement of Light Pollution

By Dr Noorali T. Jiwaji

Stargazers, young and old, students and teachers, amateur and professional astronomers are all currently taking part in a global experiment to document and understand the amount of light pollution in our night skies. Between February 25 and March 8, you can also go out into the night to determine how many stars can be see (or not seen!). The more the light there is around you, the fewer the stars you will see. And I am not talking about the lights that shine around you – those will certainly blind you and you will see hardly anything. What the experiment is about is the amount of light coming from the sky. Any light from the bulbs that unnecessarily and wastefully point up into sky gets scattered (reflected back) by the molecules and particles in the atmosphere. This makes the atmosphere brighter so you can’t see the dimmer stars. When travelling upcountry, you will have seen the breathtaking skies and notice the difference between that and the stars you can see in a town or city.

Join this exciting project, called “The Globe at Night”, and make an impact on how we use our lights, and contribute to the protection of our beautiful dark skies. If you are connected to the Internet just go to http://www.globe.gov/GaN/ and follow a few simple instructions. You will be guided to how you can locate the Orion constellation and match the stars that you see with several star charts that show the constellation in various light conditions. Report your observations, using a form provided in the website. Note that the report form works better with the Internet Explorer browser.

For those who are not on the Internet, you can also observe using these nine steps and report the results to me and I will submit them on your behalf.

1. Note the name of the town or city and area,

2. Find your latitude and longitude (if you can).

3. Look for a place away from lights and as dark as you can get

4. Find Orion by going outside an hour after sunset (at about 7-10pm local time it will

be well up in the eastern sky).

5. Match your nighttime sky to one of the magnitude charts (see below).

6. Note the date and time of your measurement

7. Note the sky condition (hazy, smoke, dust, fog, rain)

8. Note the cloud condition (clear or almost clear, quarter cloudy, half cloudy,

or more than half cloudy, fully cloudy)

9. Note any other related matter.

10. Report your observation as given below.

Compare the view of your nighttime sky to the Magnitude Charts at http://www.globe.gov/GaN. This will determine the magnitude of the faintest stars that you can see at your location.

If you can, then observe from more than one place, either on the same day or on any other day within the period up to March 8th. Your second place should be at least a kilometer away from your first location. Look for a place that is different from the first in lighting conditions and observe from the darkest place you can find. Write a separate report for each set of observations. Have an exciting star viewing activity.

End

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