Professor Jim Al Khalili from the University of Surrey delves into over 50 years of the BBC science archive to tell the story behind the emergence of one of the greatest theories of modern science, the Big Bang. The remarkable idea that our universe simply began from nothing has not always been accepted with the conviction it is today and, from fiercely disputed leftfield beginnings, took the best part of the 20th century to emerge as the triumphant explanation of how the universe began. Using curious horn-shaped antennas, U-2 spy planes, satellites and particle accelerators, scientists have slowly pieced together the cosmological jigsaw, and this documentary charts the overwhelming evidence for a universe created by a Big Bang.

D-Day: As It Happens D-Day: As It Happens tells the story of this pivotal event in 20th-century history in a completely new way. Using newly-analysed archive footage, viewers can track the progress of seven people who were there on the day, each of them a real participant in the 1944 invasion. And they can do so moment by moment in real time, encountering the twists and turns of the fighting at the same time as the D-Day seven did, and learning their fate as the action unfolds in parallel with the present, Narrated by Peter Snow, with Channel 4 presenter and former marine Arthur Williams, and experts including former British Army officer Colonel Tim Collins and front-line journalist Lorna Ward. The first programme tells the back stories of the real people that the event is following in real time and sets out their missions over the following 24 hours. The D-Day seven include a paratrooper, a midget submariner, a nurse and a military cameraman.

Dr Adam Rutherford tells the extraordinary story of the scientific quest to discover the secrets of the cell and of life itself. Every living thing is made of cells, microscopic building blocks of almost unimaginable power and complexity. The first part explores how centuries of scientific and religious dogma were overturned by the earliest discoveries of the existence of cells, and how scientists came to realize that there was, literally, more to life than meets the eye.

The series highlights the major events which have shaped the Earth's history and allowed life to flourish. Follow Dr Stewart's personal journey to some of the most remote places on the planet. The atmosphere is Earth’s protective layer, cloaking us in a warm, oxygen-rich embrace and shielding us from the cold hostility of space. It acts as a natural greenhouse, keeping the Earth 51 degrees Fahrenheit warmer than it would otherwise be. Yet the atmosphere is also full of contradictions. It’s immensely powerful but at the same time highly sensitive. It’s destructive, yet it shelters us. It was created in part by the planet’s first organisms, and it continues to be essential for life.

Hundreds of years ago in faraway Iceland the Vikings began to write down dozens of stories called sagas - sweeping narratives based on real people and real events. But as Oxford University's Janina Ramirez discovers, these sagas are not just great works of art, they are also priceless historical documents which bring to life the Viking world. Dr Ramirez travels across glaciers and through the lava fields of Iceland to the far north west of the country to find out about one of the most compelling of these stories - the Laxdaela Saga.

Dr Jago Cooper reveals the history of some of South America's ancient civilisations. He begins with an epic journey into the remote Peruvian Andes in search of the mysterious Chachapoya people. Once numbering half a million, they were known as the 'People of the Clouds'. Dr Cooper reveals how they developed sophisticated methods of recording stories, traded in exotic goods found hundreds of miles from their territory, and had funeral traditions that challenge assumptions about ancient human behaviour. His search for evidence takes him to astonishing cliff tombs untouched for 500 years and one of the most spectacular fortresses in South America, where the fate of the Chachapoya is revealed.