Only 5.6 percent of these cases were not explained. Testimonies by people are often very inaccurate and dramatized. People have the tendency to explain everything they see, which is not usually completely accurate. The unaided human eye can be tricked into hallucination and has an inaccurate depth perception. Radar is much more reliable to identify objects, but it cannot detect many characteristics that separate natural phenomena and physical objects.
Radar often picks up ionized gas, rain, or thermal discontinuities.
Electronic interference is also a frequent problem. Either way, scientists are left with many unanswered questions. There are many mysteries about UFO's with many indefinite answers. Many investigators have tried to solve some peculiar questions about UFO's, but many of their conclusions cannot be proven. In 1968 the United States Air Force asked Edward U. Condon, a physicist at the University of Colorado, to head a panel studying the claims of extraterrestrial crafts.