UFO clearly leaving Earth. Look how they pulsate, have different speeds and trajectories.
This video is the result of experimental forensic super resolution video applications and has become factor 10 sharper and the image more stable. After the SR-processing, pixels have been repositioned and surrounding pixels new interpolated so the video is no longer blocky.
STS-48 was a Space Shuttle mission that launched on 12 September 1991 and landed on 18 September.