Dr Helen Czerski 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.
There is plenty of food in the Pacific Ocean, but it is the challenge of finding that food that drives all life in the Pacific. In the voracious Pacific we meet a destructive army of mouths, a killer with a hundred mouths and the biggest mouth in the ocean.
Steve Backshall reveals the incredible influence that insects and their close relatives have on Earth's many ecosystems. In the grasslands of South America the landscape has been created almost solely by one team of insects - grass-cutter ants. Across the world's oceans one tiny creature plays such a key role that, without it, the largest animal on our planet, the blue whale, could not exist. And in East Africa the savannah would quickly be swamped in dung were it not for the activities of a certain beetle. Yet the greatest influence of all comes from a group of insects that have ultimately changed the colour and diversity of our planet.