One morning last week, I stepped outside the back door & realized that there was a hot air balloon travelling from west to east above our neighbor's house. It was so quiet that I didn't realize it was there until I heard it "burn". I took a picture & a video. In the video, it is very quiet--you can hear the birds chirping and the dogs barking. Close to the end of the video, the balloon does a "burn" and the dogs next door realize it is there and start barking like crazy. It was quite an experience to see one so close to the house!
