Dream I had about a balloon

The Chinese balloon in the news brought back a memory of a dream I had about a strange balloon. Myself and another person were watching a slow moving balloon shaped like a square descend slowly and silently towards the top of a hill we were looking up at. The balloon was big, about 100', and while drifting towards earth we said, "aw, isn't that pretty".The next moment there was a ground shaking rumble that knocked us off our feet.Up in the sky between the clouds jets were flying in every direction.