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Table of Contents

How Many Stars?

Energy Conservation and Environmental Awareness Groups

Protecting the Environment

Protecting the Environment

Light pollution not only obscures the natural beauty of the nighttime sky but it also contributes to the emission of greenhouse gases (from the fuels which are burned to produce electricity).

Properly designed lights which reflect light downwards can use much less wattage to achieve the same level of illumination at the ground level, thereby saving energy (and money).

The money saved by using well designed lights more that outweighs the initial extra cost of choosing well designed light fixtures for outdoor lighting.

A simple, and very effective method of determining the amount of energy wasted by nighttime illumination in your neighbourhood is to simply determine the number of stars that can be seen in the nighttime sky on a clear (cloudless) moonless night... here's how.....

Counting Stars


Prepared by YES I Can! Science Team at McMaster University,
for the Canadian Space Agency.