Saw a green star-like object hovering, then it shot off several kilometers in 1-2 seconds at an incredible speed, hovered & disapeared.My family and I went to see the July 1st fireworks (for Canada Day) in Calgary that were scheduled to be between 10:45pm and 11:45pm that day. They were being launched off the Centre Street Bridge in Calgary, so we decided to go to the Sunnyside Bank Park and watch the fireworks from the top of the hill to get a good view (on Crescent Road NW near 2nd Street NW). I remember looking at the time on my cell phone and at 10:51pm I made a comment to my wife that they were late with their fireworks.Within a few minutes of that time, the fireworks had started, and they lasted approximately 15 minutes. Once the fireworks finished, I waited for maybe 30 seconds to see if any more were coming, but all there was now was smoke above the Centre Street Bridge. I looked at my cell phone again and the time was 11:09pm. I made another comment to my wife that they were liars, as I was expecting fireworks to last an hour. She laughed, and shortly after that she asked me, "What is that green light up there?" I looked up in the sky and saw a green stationery star-like object in the sky, hovering probably above Centre Street (not directly above us, just slightly east from us) and it was north of the Centre Street Bridge. I don't know exactly how high it was, but it there was cloud cover and the object was still below the clouds. At that moment when I first saw it, I didn't know what to think, as it was stationery. In my mind I immediately related the light to some of the fireworks from before (although it was hovering and not rising and falling like a firework) or maybe a helicopter with a green light (I didn't hear any helicopter noise either, but the object was very high).The object hovered in that spot for several seconds (10 to 20 seconds), then suddenly it shot off in the south east direction at a speed that I had never witnessed any airplane do before. It shot off several kilometers in the south east direction within 1 or 2 seconds, the came to a sudden stop, and it hovered again for several seconds. My heart immediately jumped at that moments, as I suddenly knew that whatever this was, it definitely was not a firework, a helicopter or any other conventional aircraft known to me.The light then suddenly vanished, as me and my wife started talking to each other in great excitement about what we just witnessed. The light appeared again, I reached for my cell phone to start recording, but as soon as I had the phone ready, the light vanished again, and we did not see it after that.When my wife first noticed the object, it was hovering lower, then it shot up with incredible speed and became stationery, at which point she drew my attention to it. I had missed the first part when it ascended, and I only saw it shoot horizontally across the sky. It was Canada Day fireworks and there were thousands of people scattered all around to watch the fireworks.My wife, my 16 year old son and I all saw the object. The people standing behind us saw the object. Since there were thousands of people present, I'm sure that many others saw the object. I hope that many more reports from that evening are filed, as I'm sure there are countless other witnesses to the event.It was just a light in the sky and if my wife had not pointed it out to me, I would have missed it. Due to that fact, I'm sure that majority of the spectators did not see this light, but those that were looking up in the right direction would have seen it for sure.