green light, toronto canada

Date is a guess, but I figure the early eighties. Was home in my bedroom and couldn't sleep because it was a very humid summer night. Stood by the open window and looked at the night sky (north). I saw a very bright green circular object larger than the size of a full moon travel from S/E to N/W. This looked like a "glow in the dark" type of green. It was so bright that it left a green streek of light behind it.
 I've seen shooting stars before but they were always pin points of light that quickly shot across the sky and burned up. This was huge and traveled much slower. My window was open and the object made no noise. The only thing I could think of was that it might be an meteor that graised off the atmosphere and skipped back into space. From what I understand if it was a meteor up close, it would be traveling faster then the speed of sound and I should have heard a sonic boom.
Date is approximate.  PD