Sept. 1970. Kingston Ontario. Spherical grren orb. 3 minute duration. Bright green orb travelled slowly and then took off extremely qui

Spherical object about 1/4 mile away travelled west to east along the shore of Lake Ontario at Kingston.  Object was lime green and about the size of a street light or slightly larger.  It travelled very slowly along the shore (above the water) at a height of about 300 feet.  It travelled in a straight line at constant altitude. Then it shot off, extremely fast, in a south-east direction in what appeared to be an arc. It got smaller very quickly which I assume meant that it was travelling away from me.
This was a single object and I never heard of a report about ir on the local news. I was a first year university student (Queen's University). The object was bright enough that I first saw it shining through my room curtains. I then went to the window and watched it for about 3 minutes.