A mysterious balloon the size of 18 buses seen hovering over Billings, Mont., has been confirmed to be of Chinese origin. At a briefing Thursday, the Pentagon said the balloon had been observed via multiple methods for a number of days, including piloted aircraft. A senior defense official said the balloon wasn’t shot down over concerns about the damage on the ground that could cause. China stated on Friday it is a "civilian airship" used mainly for meteorological research and regretted it blew off course.