What on Earth?

Circling high above the Earth at 17,000 miles an hour, satellites uncover startling mysteries invisible to observers on the ground.

With high magnification optics, infra-red scanning and advanced ground-penetrating radar, they capture images that lead us on startling journeys into hidden worlds revealing the secrets of the past and astonishing natural phenomena.

Some of these images are breath taking, but some are bizarre. One could be a vital clue to the location of the Garden of Eden, another might reveal the legendary golden city of El Dorado.

What is the terrifying truth behind the massive tsunamis seen from space that disappear without trace, and the sinister blood-red lake in war-torn Baghdad?

Could strange spirals in the dirt of the Kalahari desert be the marks of an ancient culture, or something more sinister? Are the massive animal shapes in the mountains of Peru signs evidence of ancient astronomy?

Have satellites uncovered a secret underground base built by a mad Dictator? Is it possible that orbital imaging could capture the split second when an airliner broke up and fell from the sky.

All these questions and more will be answered as experts investigate in 'What On Earth?'