"Imagine you see highly advanced vehicles, they appear on radar systems, they look bizarre, no one knows where they're from. This happens on a recurring basis, and no one does anything," said Mellon, who now works with UFODATA, a private organization. Because agencies don't share this type of information, it's difficult to know the full extent of activity. Still, he estimated that dozens of incidents were witnessed by naval officers in a single year, enough to force the service to address the issue.