> This comment on ArsTechnica on the same subject links to some videos which have nice explanations for the videos: https://arstechnica.com/science/2020/04/navy-releases-three-... Basically lens flare, balloon, and a plane.
The video links there are https://www.youtube.com/watch?v=4Btns91W5J8&t=7s , https://www.youtube.com/watch?v=PLyEO0jNt6M&t=20s , https://www.youtube.com/watch?v=s1oTg0kxzDs .