We cannot yet explain mysterious sightings in the sky, Nasa panel says independent.co.uk - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from independent.co.uk Daily Mail and Mail on Sunday newspapers.
The US space agency Nasa officially joined the search for unidentified flying objects on Thursday, but in keeping with the stigma associated with the subject, it refused to name the head of the new.