What on Earth?

Desperate signs from POWs in Vietnam are captured by satellite, a fleet of ships are found stranded in the middle of a desert and strange walls stretch vast distances across northern California.

Satellites discover stealth technology deep inside China, an unidentified cloud swamps America’s skies and something truly massive is lurking beneath Loch Ness.

Satellites spot strange spiral markings in the remote African desert, a deadly black blob threatens the Florida Keys and something massive is found deep beneath the ice of Antarctica.

A satellite spots a set of huge arrows in the Badlands of the American west, a blood red waterfall stains Antarctica's snows and massive holes plague the Siberian landscape.

The face of Christ is found in a field in Hungary, a photo claims to show who down a passenger jet in Ukraine and a sinister shape in the mountains of Afghanistan leads investigators to a hidden genocide.

Experts investigate a strange structure found in the heartlands of Mongolia, bizarre rings in Spain could lead to the lost city of Atlantis and a floating island may be on a collision course with New Zealand.