Horizon investigates the current benefits and disadvantages of Hormone Replacement Therapy (HRT).

This Horizon episode is about the new and terrible threat from tuberculosis which kills more people than any other infection.

This is the first part of a two-part Horizon series presenting a portrait of Richard Feynman, the American Nobel Prize winning physicist.

This is the second part of a two-part Horizon series presenting a portrait of Richard Feynman, the American Nobel Prize winning physicist.

This Horizon episode attempts to answer the question if it will be possible to 'terraform' Mars by creating a new atmosphere, and then adding water and plants to make the planet habitable.

Horizon investigates how market research, opinion polls, TV ratings, and consumer surveys have got it disastrously wrong. Commercial decisions depend increasingly on this information, but just how good is that information?

This Horizon documentary looks at how the ancient Egyptians built the pyramids without the use of the wheel, ramps, or levers.

This documentary by Horizon looks at how the Hubble space telescope is uncovering evidence of black holes in our distant galaxies.

This is a Horizon update to the story of the Stone Age man found frozen in an Alpine glacier in 1991.

Horizon shows how American scientists struggled to fulfil the dreams which challenged fundamental scientific laws.

In this episode, Horizon examines the latest scientific evidence about the Dead Sea Scrolls.

Horizon presents the story of a robot named Dante, who goes into an active volcano in Antarctica to find out if volcanoes contribute to the ozone hole in our atmosphere.

Follows a team of archaeologists led by Michael Novacek as they try to retrace the steps of an expedition launched by the American Museum of Natural History in the 1920's. The original expedition sought the origins of humanity but instead came across a virtual graveyard of the dinosaurs.

Horizon reports on scientists who are planning smart aircraft wings and smart buildings that can sense earthquakes.

In this episode, Horizon examines Asthma, the illness that is the most common condition of the developed world.

Horizon looks at causes of violence and asks psychologists to interview men and boys with a record of violence.

In this story, Horizon explores the endless stream of digital information available on demand to the public, but do we need, or even want it?

Horizon describes how researchers discovered that a lethal gas, called nitric oxide, was behind some of the most basic functions of our bodies.

This documentary by Horizon looks back into the 1980's where the work of pioneer researchers trying to determine if chimpanzees could understand language was attacked as charlatanism. Now the public opinion has moved back in favour of the idea that apes can indeed talk to us. The program looks at the latest developments in the chimpanzee language laboratories in America.

Horizon investigates how life began on Earth. Did it evolve on land surfaces on Earth, in the sea, or in space?