'No evidence' UFOs are alien spacecraft, but they're not American, Pentagon says

Then what are they?

On July 16, 1952, Coast Guard seaman Shell Alpert took this photo of four roughly elliptical blobs of light in formation through the window of his photographic laboratory near Salem, Massachusetts. The U.S. Air Force's UFO task force, Project Blue Book, investigated the image and deemed it "unexplained."
On July 16, 1952, Coast Guard seaman Shell Alpert took this photo of four roughly elliptical blobs of light in formation through the window of his photographic laboratory near Salem, Massachusetts. The U.S. Air Force's UFO task force, Project Blue Book, investigated the image and deemed it "unexplained."
(Image credit: Science History Images/Alamy Stock Photo)

A new report from U.S. intelligence officials claims that there's no evidence that the unidentified flying objects (UFOs) sighted in recent years — even objects that seemed to perform aerodynamic feats beyond the capabilities of human aircraft — are extraterrestrial in origin. 

But the objects aren't American-made technologies, either, officials said in the report. In that case, what are these UFOs? It's hard to say with certainty, as many of the likeliest explanations — weather balloons or other airborne experiments, for instance — are contradicted by the unusual speed or maneuverability of the objects, according to the report.

Mindy Weisberger
Live Science Contributor

Mindy Weisberger is a science journalist and author of "Rise of the Zombie Bugs: The Surprising Science of Parasitic Mind-Control" (Hopkins Press). She formerly edited for Scholastic and was a channel editor and senior writer for Live Science. She has reported on general science, covering climate change, paleontology, biology and space. Mindy studied film at Columbia University; prior to LS, she produced, wrote and directed media for the American Museum of Natural History in NYC. Her videos about dinosaurs, astrophysics, biodiversity and evolution appear in museums and science centers worldwide, earning awards such as the CINE Golden Eagle and the Communicator Award of Excellence. Her writing has also appeared in Scientific American, The Washington Post, How It Works Magazine and CNN.