Horizon

Alcohol is by far the most widely used drug - and a dangerous one at that. So why are so many of us drinking over the recommended limits? Why does alcohol have such a powerful grip on us? How much of our relationship with this drug is written in our genes? What are the real dangers of our children drinking too young? Addiction expert John Marsden, who likes a drink, makes a professional and personal exploration of our relationship with alcohol. He undergoes physical and neurological examinations to determine its impact, and finds out why some people will find it much harder than others to resist alcohol. Even at the age of 14 there may be a way of determining which healthy children will turn into addicts. John experiments with a designer drug being developed that hopes to replicate all the benefits of alcohol without the dangers. Could this drug replace alcohol in the future?

Plastic surgeon Dr Rozina Ali leaves the operating theatre behind for the frontiers of skin science and asks if it is possible to make your skin look younger without surgery. She discovers the latest research about how the foods we eat can protect our skin from damage, and how a chemical found in a squid's eye is at the forefront of a new sun protection cream. She also finds out how sugar in our blood can make us look older, and explores an exciting new science called glycobiology which promises a breakthrough in making us look younger.

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?