The first part, Everything, sees Professor Al-Khalili set out to discover what the universe might actually look like. The journey takes him from the distant past to the boundaries of the known universe. Along the way he charts the remarkable stories of the men and women who discovered the truth about the cosmos and investigates how our understanding of space has been shaped by both mathematics and astronomy.
Horizon goes behind the scenes at NASA as they countdown to the landing of a 2.5 billion-dollar rover on the surface of Mars. In six days time, the nuclear-powered vehicle - the size of a car - will be winched down onto the surface of the Red Planet from a rocket-powered crane. That's if things go according to plan: Mars has become known as the Bermuda Triangle of space because so many missions there have ended in failure. The Curiosity mission is the most audacious - and expensive - attempt to answer the question: is there life on Mars?
The Earth, the sun, the stars, and everything we can see, only comprise five percent of the universe. But what about the other 95 percent? Scientists are puzzling over dark matter and dark energy, the mysterious components that make up the rest.
Were "little green men" trying to contact us? Over 40 years ago, extremely constant pulses were detected reaching the Earth from outer space. It caused a great sensation. Using a radio telescope larger than a baseball field, scientists looked for the source of these signals and found - pulsars.