While waiting for a 4th of July fireworks display to begin, I and 3 friends noticed a blinking green, sometimes red, light in the sky.

The object hovered in the same spot for maybe 10 minutes. I would look at it off and on. I also took a 10 second video. It was very stable in it's position. I saw nothing beyond the blinking light. (I think I would have noticed the bodyframe of a helicopter. But only that one blinking light was visible.) The light was greenish in color, though at one point it turned red. I did see it move, quickly, and to the left. Then it suddenly came to a dead stop. To my eye it did not maneuver like a helicopter. It was too rock steady. And it's start-stop maneuver was too crisp. I stopped looking when the fireworks display started. About 10 minutes after the start of the display I remembered to check for the light, but it was gone. (My video is not very dramatic, but please note the small blinking light a little above the big tree that sits center-left in the video frame.)