I was driving west on highway 16 and off to the south a cone shaped glow appeared to be moving southwest. The shape look very similar to what I describe as a comet shape( it had what seemed to be a tail) and moved steady across the sky, went behind a cloud, reappeared and then disappeared in the distance. I could see no color but it had a very strong glow in the sunny daylight noon hour.Time was 12:05 MST Thursday Nov4 1999 I was travelling west on Highway 16 just North of a small town called Spruce Grove. I notice this particular bright cloud out my drivers side window looking south. I looked at it and it had sort of a comet looking appearance about it --mainly this cloud seemed to have a tail and then I noticed it was moving. I looked to the side several times and it seemed to be moving a pace similar to an aircraft. I had to drive about a mile in order to find a place to pull over and observe the object safely. When I picked up the object again in the sky it had move further south and was still quite visible due to its brightness. I measured the size of the object in the air with my arms extended and it measured to be about 1/2 centimetre. It moved behind a cloud and then reappeared and move steadily off to the distance. The pace was consist while viewing this object.