Even after thousands of years of ice crushing the northern hemisphere and temperatures of 20 degrees lower than those of today, many of the great giants of the ice age still walked the earth. It was only when the world had warmed up again that mammoths, woolly rhinos, sabre-toothed cats, giant ground sloths and glyptodonts finally became extinct. Professor Alice Roberts sets off on her last voyage back to the Ice Age to discover why.

Our icy adventure begins with host Dr. Iain Stewart in the Alps, where he goes down an ice crevasse to show viewers how snowfall develops into expansive masses. Then, we see how ice can shape the earth's topography giving rise to features like Yosemite National Park and Manhattan Island, in NY. Finally, journey to Greenland and see how ice sheets and glaciers are melting at a phenomenal rate that is likely to accelerate over the coming years, changing the world as we know it.

Earth’s oceans help make our planet different from every other planet in the solar system. As far as we know, no other place is the right temp for liquid water, the most essential ingredient for life to exist. The oceans are Earth’s primary stabilizing force, and their immense power helps to shape the appearance and behavior of the entire planet and everything living on it. And they are also the planet's great unknown - their deepest points have been visited less than the surface of the moon.

The final part reveals how our knowledge of cells has brought us to the brink of one of the most important moments in history. Scientists are close to repeating what has happened only once in four billion years - the creation of a new life form.

D-Day: As It Happens is a 24-hour history event to be broadcast across TV, web, mobile devices and social media, telling 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 second programme reveals what happened to the seven real people the event is following in real time, and also rounds up the events of D-Day.

Tyson describes the discovery of cosmic rays by Victor Hess through high-altitude balloon trips. Swiss Astronomer Fritz Zwicky, in studying supernovae, postulated that these cosmic rays originated from these events instead of electromagnetic radiation. Also tells how Vera Rubin observed that the rotation of stars at the edges of observable galaxies did not follow expected rotational behavior leading to consider the existence of dark matter. This further led to the discovery of dark energy to account for the increasing rate of expansion of the universe. Tyson then describes the interstellar travel of the two Voyager probes. Tyson tells the Carl Sagan's role in the Voyager program, including creating the Voyager Golden Record to encapsulate humanity and Earth's position in the universe. Tyson concludes the series by emphasizing Sagan's message on the human condition in the vastness of the cosmos, and to encourage viewers to continue to explore and discover what else the universe has to offer.