Researchers have been poring over recently declassified videos shot by U.S. Navy pilots over the East Coast in 2015, showing mysterious flying objects that behave like no known aircraft. Thanks to newly updated radar systems in Navy jets, the videos have aided scientists by providing “testability” and previously unknown metrics about UFOs. “We now know they fly between Mach 5 and Mach 20 — five to 20 times the speed of sound,” Kaku said. “We know they zigzag so fast that any pilot would be crushed by centrifugal force. That they have no exhaust that we can see.” The explanations usually invoked for UFO sightings — meteors, weather balloons, even the planet Venus — can’t explain these live-action high-precision shots, said Kaku, leading to either of two possible conclusions: They are of human origin, representing a technology so cutting-edge that even leading scientists are puzzled by it. Or, he said, “maybe they are evidence of an advanced outer space civilization.”
Kaku emphasized, “maybe they are extraterrestrial.” After all, he noted, the universe is 13.8 billion years old, while earthly science was born merely 300 years ago; on any of 4,000 recently discovered exoplanets, where life as we know it might be able to exist, alien civilizations may well have had much longer to advance their scientific and technological skills.