Toronto - Over 2,000 people joined in Toronto’s Earth Hour celebrations on Saturday night at the Ontario Science Centre. In addition to turning off many of the lights in its buildings, parking lots and TELUSCAPE from 8pm to 9pm, the Science Centre attracted participants with a free Star Party. Festivities included views of Saturn and Mars through high-powered telescopes, and numerous activities and demonstrations that centered on energy conservation and the environment.

Hundreds of star-gazers also took part in the cross-Canada StarWatch experiment that asked people to count the number of stars visible in the Little Dipper during Earth Hour and then again when the lights were turned back on to see if turning out the lights impacted the quality of the night sky. So far, participants have submitted data from 150 locations. An interactive map of the results can be found online at

“The impact of Earth Hour on the quality of the night sky was higher than we expected. When the lights came back on, the three stars in the Little Dipper that we were able to observe were harder to identify and the sky on the horizon became noticeably brighter. Measurements showed 75 percent more light arriving from a given patch of sky”, said Sara Poirier, Astronomy Researcher for the Ontario Science Centre. “The great thing about this experiment is that it provides a quantitative measure that we can compare from year to year and an opportunity to raise awareness about the important issue of wasted energy. Light pollution is the result of wasted energy. Every year, billions of dollars is wasted putting light up into the sky rather than the ground where it is needed.”

Part of regular offerings on the Ontario Science Centre’s interactive website,, the StarWatch experiment is just one of the many innovative programs the Centre has developed to reach out and engage a broader audience beyond its walls — onsite, online and offsite.

The Ontario Science Centre uses science as the lens to inspire and actively engage people in new ways of seeing, understanding and thinking about themselves and the world. The Centre is also a leading developer of interactive exhibitions for science centres around the world. The Ontario Science Centre is an agency of the Government of Ontario.