For decades, people who reported UFO sightings have described encounters with mysterious visitors dressed entirely in black.

Thousands of people have reported UFOs or alien encounters in Northern California. That number could soon go up.

If you're a skeptic, these UFO sightings will convince you that the truth is out there—and it may not be from Earth.

Military and commercial pilots are increasingly treated as star witnesses in UFO debates, but psychologists warn their dramatic testimonies cannot, on their own, prove alien visitors.