Sunset over the plains of Kenya's Maasai Mara, one of Africa's most protected wild spaces. And home to the fastest land animal on Earth, the cheetah. These agile cats have always been thought of as daylight hunters. They target prey from more than a kilometre away and chase it down at over 100 kilometres an hour. In one of these plains, two cheetah brothers attempt a high-speed night hunt with a gang of powerful hyenas on their trail.

Global CO2 emissions coming from aviation will go from about 2% to, by 2050, something closer to 20%. Technology is the only key to open up a brighter future that can be sustainable at the same time. The way we fly is about to change, driven by a new breed of aviators not afraid to think differently. From clean, green electric aircraft to autonomous sky taxis, could the days of the jet age be numbered?

The third assault on the tattered remains of Roman civilization came from even further North, where the melting glacial ice had created immense sheltered fjords, leaving its inhabitants little choice but the sea. These fearless navigators understood that dominion over the oceans was the key to their ambitions.
Where the Romans expanded incrementally, the Vikings adopted a bolder, more aggressive approach. So was it the Dark Age which failed Europe, or the stifling uniformity of the great Roman experiment? Were the lost tribes more victim than failure? Richard Rudgley will hope to shed new light on the real secrets of the so-called Dark Age.

Stars helped create us, building and spreading the ingredients for life to develop. But there will definitely be a point in the future when, in the future when, you look up, you will no longer be able to see stars.
For billions of years, stars brought life to the universe. Now, they're dying out in a star apocalypse. What's causing the die-off, and what happens to life when the lights go out?

We're unlocking the secrets of our planet's voyage and discovering that earth's journey affects us all. The Earth is extremely dynamic. It is spinning on its axis, it's whirling about the sun and it's corkscrewing throughout the this galaxy. And there is the fact than Andromeda and the Milky Way are currently 2.5 million light-years apart, but they're hurtling towards each other at over 250,000 miles an hour. A collision is inevitable. As stars, dust, and gas swirl around each other, gravitational interactions could slingshot our solar system out into intergalactic space.

From the frozen poles to the searing deserts, this episode shows how animals have come up with strategies to survive the uneven amounts of sunlight that fall on our planet over the course of a year. The exception is on the equator, where the duration of day and night remain the same throughout the year. Here, this guaranteed sunlight drives the great diversity of life in the tropical jungles.