Former NASA engineer, space journalist, and historian who has written multiple books and articles on space travel and often debunks supposed UFO sightings.
After a 22-year career with NASA, James Oberg, continued as a freelance consultant and journalist in spaceflight operations and safety. Oberg wrote thousands of articles and ten books all about space travel.
He dismissed UAP sightings as either hoaxes or falling into three categorizable scientific explanations: Super-High Plumes (rocket or missile plumes, especially lit by the Sun on a dark sky), Space "Dandruff" (ice flakes, fragments of insulation, etc. flying alongside a space vehicle, especially seen by backward-facing cameras), and Twilight Shadowing (objects that move from shadow into sunlight in space appear as if coming from behind the clouds or from beyond the edge of the Earth).
"Our sensory system is functioning absolutely perfectly for Earth conditions," Oberg explained. "But we're still a local civilization. Moving beyond our neighborhood has been visually confusing."
Oberg attested to the origin of the STS-48 Zig-Zag Video and shared never before published charts. On his website, Oberg wrote, "The attached two charts provide convincing proof that the famous zig-zag dots of the STS-48 shuttle flight (September 1991) are exactly what space experts inside and outside NASA have always said they were: routine nearby small sunlit debris hit by the expanding exhaust of a shuttle steering rocket triggered randomly by the computer autopilot which was steering the spaceship. More elaborate and exotic 'explanations' rely on misinterpretations of the images and on a deliberate omission of relevant data such as shown here (these two charts have never been published by proponents of extraordinary scenarios -- they apparently never asked NASA for them)."