What on Earth?

Six more mysteries captured from space are investigated, including weird, barren rings in the Namib desert, a vanishing island and a lost city in the heart of the Amazon jungle.

Experts are baffled by a beautiful yet mysterious formation in the Sahara desert, and extraordinary clouds emanating from the Indian Ocean may be evidence of a terrifying new weather weapon.

An astronaut photographs a strange ring of ice on the world's oldest and most mysterious lake.

A possible smokescreen over North Korea worries military analysts, while an amateur archaeologist makes an extraordinary discovery with the help of a satellite image