UFO mystery may be result of advanced 'stealth civilization' living on Earth among us, say Harvard scientists - as they reveal where their secret bases could be located
UFO mystery may be result of advanced 'stealth civilization' living on Earth among us, say Harvard scientists - as they reveal where their secret bases could be located
- READ MORE: Navy sub tech spots UFO 'faster than speed of sound underwater'
Skeptics have long questioned why UFOs, if they are alien craft, would visit Earth so often.
But two Harvard scientists suspect the beings may have been here all along.
In a new research paper, they estimate there is …