What on Earth?

Six breathtaking images reveal six unfathomable mysteries.

Weird barren rings in the Namib Desert, an island the size of Manhattan that vanishes without trace and a lost city in the heart of the Amazonian jungle. What on Earth? Investigates six more mysteries captured from space.

First seen from space in 1965, the Eye of the Sahara is a beautiful 25 mile structure, but how it formed remains a mystery. And are extraordinary clouds emanating from an island in the Indian Ocean evidence of a terrifying new weather weapon?

NASA astronaut Mike Barratt, describes photographing a strange ring in the ice on the world's oldest and most mysterious lake from the International Space Station. More rings on Lake Baikal have been seen since, they baffle scientists.

A possible smoke screen over North Korea worries military analysts while an amateur archaeologist makes an extraordinary discovery with the help of a satellite image; has this image revealed not one but two forgotten pyramids in Egypt?

Images of earth from space reveal an intimate portrait of human activity. Cities glow bright while the wilderness remains dark. Why then is the Australian outback, lit up like a series of vast cities?