Horizon investigates the possibilities of time travel
Percy Pilcher's Flying Machine
Could an unknown Englishman have beaten the Wright brothers to achieving powered flight?
The Hunt for the AIDS Vaccine
Horizon tells the microbiological detective story of the hunt for an AIDS vaccine
Last Flight of the Columbia
What really went wrong on the Space Shuttle Columbia?
The Bible Code
Does the Bible contain a hidden code predicting the end of the world?
The Big Chill
Is Britain heading for an Ice Age?
SARS: the True Story
From unnamed infection to globe-trotting killer - the fight to contain Sudden Acute Respiratory Syndrome
Why did an American Airlines Airbus A300 crash into a New York suburb in November 2001?
God on the Brain
Is a part of your brain hardwired to generate religious feelings?
The Secret Life of Caves
In caves deep beneath New Mexico biologists investigate bacteria that live without oxygen
Life on Mars
The latest views on the chances of life existing on the Red Planet
Patterns of earthquakes across decades suggest they can move along predictable lines
Trial and Error
Jesse Gelsinger died after a gene therapy trial, causing experts to question the treatment
The Day We Learned To Think
70,000 year old art hints at the very start of human intelligence
Could a drug like Viagra help women with sexual problems?
How would a major city like London react to an attack using a radiological dirty bomb?
Horizon weighs up the pros and cons of methods to prevent asteroids colliding with Earth
People with narcolepsy fall asleep all the time. Could their condition offer us all a route to a future without tiredness?
The Mystery of Easter Island
Archaeologists piece together the rise and fall of the world most isolated civilisation