Dangerous Earth

Series showing how new camera technology is revealing the inner workings of the Earth's most spectacular natural wonders. Dr Helen Czerski examines the extraordinary new images - from eyewitnesses, scientists and film-makers - that are transforming our understanding of how and why these phenomena form. In this episode Helen peers into the heart of the storm to find out how advances in technology are giving new insight into tornadoes - the fastest winds on the planet. From the breathtaking footage that capture the extreme weather events that produce them, to the latest experiments investigating their incredible destructive power, Helen discovers how understanding the subtle changes deep within the storm are improving predictions of when and where these devastating beasts will strike. episode 5.

Series showing how new camera technology is revealing the inner workings of the Earth's most spectacular natural wonders. Dr Helen Czerski examines the extraordinary new images - from eyewitnesses, scientists and film-makers - that are transforming our understanding of how and why these phenomena form. In this episode she examines the hottest natural phenomena on the planet - lightning. Bolts of lightning five times hotter than the surface of the sun strike our planet over 3 million times every day - and yet we still know little about this deadly force of nature. Now, specialist photography is revealing how lightning travels through the air, high-speed cameras are unlocking the secrets of upward lightning that's triggered by our urban landscapes, and scientific expeditions are capturing rare images of intense electrical discharges over 80 kilometres wide.

Dr Helen Czerski begins the series by looking at the anatomy of an avalanche, using shocking eyewitness footage from within an avalanche and CT scans showing the microscopic changes that cause them.