I have been working on my course at JCU, and one of our tasks has been to estimate the orientation of the Milky Way with respect to the Earth's orbit.
The obvious way to do this is to look at the Milky Way. That's impossible in Toronto, and for a LONG way out. At my home downtown, the limiting magnitude is between 0 and 1, depending on how directly you're forced to look into bright lights. My home is something of a pathological case, though, as the club just down the street likes to shine searchlights into the night. A more realistic case would be midtown Toronto (I am using Yonge and Eglinton), where most bright stars can be seen clearly. The Milky Way is completely invisible, though.
I travelled to the suburb of Aurora, Ontario (about 40km north of the city limit, or one hour of travel by train in rush hour) and the skies were not substantially better than midtown. You would think that, this far out, in a small city of 40,000 with unbuilt land all around, we would be able to find dark skies. You would be wrong. The Milky Way was still invisible to the naked eye and at the very limit of vision in binoculars.
Two interesting sites about light pollution in Southern Ontario:
- A 1976 paper by Richard Berry shows a light pollution map. Anything within an hour's drive of Toronto is very poor.
- A more modern sky brightness map of the GTA.
Ontario does have several dark sky preserves designed to maintain a few places where human eyes will be able to see the universe. This is a good start. What really needs to happen, though, is for cities like Toronto to install simple shades on outdoor lights to keep them directed downward. If they were reflective, the bulbs could also be replaced with a lower wattage, thus saving energy costs.
Sometimes it's the little things that matter the most.
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