NASA is on a mission to send humans to Mars within just 15 years, but to reach this next frontier of space exploration, experts must discover new technology and cutting-edge science that protects astronauts from the Red Planet's deadliest killers.

How is the universe put together? How is it built? And how does it actually work? How the Universe Works Series 8 shows the inner workings of our planet, the solar system, the galaxies and the universe itself.
In the first episode, if a massive asteroid collides with earth, it could end life on our planet as we know it. New discoveries and cutting-edge tech reveal just how close we are to apocalypse and what it would take for the world's leading space agencies to stop it.

Cities are growing at a faster rate than any other habitat on Earth. They may seem an unlikely place for animals to thrive, but they can be a world of surprising opportunity. Leopards prowl the streets of Mumbai, peregrine falcons hunt amongst New York's skyscrapers, and a million starlings perform spectacular aerial dances over Rome. In Jodhpur, langurs are revered as religious deities and in Harar, locals live in harmony with wild hyenas. Many animals, however, struggle to cope in the urban jungle. As the architects of this environment, can humans choose to build cities that are homes for both them and wildlife?

Grasslands cover one quarter of all land and support the vast gatherings of wildlife, but to survive here animals must endure the most hostile seasonal changes on the planet. From Asia's bizarre-looking Saiga antelope to the giant anteaters of Brazil, grassland animals have adapted in extraordinary ways to cope with these extremes. In the flooded Okavango, lions take on formidable buffalo in epic battles, on the savannah bee-eaters take advantage of elephants to help catch insects and, on the freezing northern tundra, caribou embark on great migrations shadowed by hungry Arctic wolves.

The world's deserts are lands of extremes that force animals to come up with ingenious ways of coping with hostile conditions, giving rise to the most incredible survival stories on earth. A pride of desert lions are so hungry they risk hunting a giraffe several times their size, while male sandgrouse fly 120 miles each day to the nearest waterhole and dice with death to collect water for their chicks. Filmed for the first time, a tiny bat does battle with one of the world's deadliest scorpions, and in Madagascar, a locust swarm of biblical proportions is seen as never before.

An alarming decline in insect populations could devastate all life on earth. What's causing it, and can anything be done to stop it?
Insects are disappearing across the world. If we lost our pollinators, we would lose 80 to 90% of the plants on the planet. That is not an option. It's the ecosystems on this planet that keep humans alive. Scientists warn us that the insect apocalypse is entirely possible.