Horizon goes behind the scenes at Nasa to discover how it is preparing for its most ambitious and daring mission: to land men - and possibly women - on the surface of Mars. It's over 40 years since Neil Armstrong made the first human footprint on the moon. But getting to the red planet would involve a journey of at least three years. Horizon meets the scientists and engineers who are designing new rockets, new space suits and finding ways to help astronauts survive the perils of this long voyage. And it turns out that having the 'right stuff' for a mission to mars might not be quite what you expect.

Horizon tells the inside story of the search for Malaysia Airlines flight MH370. With access to the key players on the frontline in the southern Indian Ocean and the British satellite engineers who tracked the plane's final hours, Horizon breaks open the biggest mystery in aviation history. The film reveals how MH370 disappeared in a radar blind spot; what investigators believe happened to the aircraft in its last minutes; and how the area in which it could be found is still to be searched. Plus Horizon examines the new technologies, like black box streaming and enhanced air traffic surveillance, that mean an airliner should never vanish without trace again.

What's worse for us: sugar or fat? To answer the hottest question in nutrition, twin doctors Chris and Xand Van Tulleken go on month long high-fat and high-sugar diets. The effects on their bodies are shocking and surprising. But they also discover that in the debate about fat and sugar, the real enemy might have been hiding in plain sight.

In February 2013, a hole opened up beneath a home in Florida, and swallowed a man. Jeff Bush was asleep when a sinkhole opened up beneath his bedroom. Despite the efforts of his brother to rescue him, Jeff was never seen again and his body was never recovered. Professor Iain Stewart travels to Florida to try and understand what killed Jeff, and why the geology of this state makes it the sinkhole capital of the world.

The hunt for life within the long-dead bones of dinosaurs may sound like the stuff of Hollywood fantasy - but one woman has found traces of life within the fossilised bones of a T Rex. Dr Mary Schweitzer has seen the remains of red blood cells and touched the soft tissue of an animal that died 68 million years ago. Most excitingly of all, she believes she may just have found signs of DNA. Her work is revolutionising our understanding of these iconic beasts.

Horizon uncovers the truth about how you really make decisions. Every day you make thousands of decisions, big and small, and behind all them is a powerful battle in your mind, pitting intuition against logic. This conflict affects every aspect of your life - from what you eat to what you believe, and especially to how you spend your money. And it turns out that the intuitive part of your mind is a lot more powerful than you may realise.

Exploring the murky and fast-paced world of the hackers out to steal money and identities and wreak havoc with people's online lives, and the scientists who are joining forces to help defeat them. Horizon meets the two men who uncovered the world's first cyber weapon, the pioneers of what is called ultra paranoid computing, and the computer expert who worked out how to hack into cash machines.

Over the last few years, our weather in Britain has become more extreme. Last winter was the wettest ever recorded, as deadly storms battered the country for weeks on end. But previous winters have seen bitter lows of -22, as Britain was plunged into a deep freeze. What everyone wants to know now is: why is our weather getting more extreme, can we expect to see more of it in the future, and has it got anything to do with climate change? In this episode of Horizon, physicist Dr Helen Czerski and meteorologist John Hammond make sense of Britain's recent extreme weather and discover that there is one thing that connects all our recent extreme winters - the jet stream, an invisible river of air that powers along 10 km above us. What's worrying is that recently it has been behaving rather strangely. Scientists are now trying to understand what is behind these changes in the jet stream. Helen and John find out if extreme winters are something we may all have to get used to in the future.

Dr Kevin Fong explores a medical revolution that promises to help us live longer, healthier lives. Inspired by the boom in health-related apps and gadgets, it's all about novel ways we can monitor ourselves around the clock. How we exercise, how we sleep, even how we sit.

As they contain no active ingredient, placebo medicines and pills should not really work, but they are now being shown to be effective in helping treat pain and depression and even alleviating some of the symptoms of Parkinson's disease. This programme explores why they work and how everyone could benefit from them.

When pioneering developmental psychologist Professor Uta Frith started her training back in the 1960s, she met a group of beautiful, bright-eyed young children who seemed completely detached from the rest of the world. It turned out they had just been given the then-new diagnosis of autism. Uta passionately wanted to know more about these children, and they inspired her to dedicate the rest of her career to studying the autistic mind. On the eve of National Autism Day, Horizon reveals how Uta's lifetime study of people with autism has transformed our understanding of this mysterious condition. In this film Uta shows how people with autism perceive and interact with the world and how, for them, another kind of reality exists. She meets people with autism who have extraordinary talents, and explains why they often fail to understand jokes. She also explores whether many of us could be just a little bit autistic.