In this program, Catalyst uncovers the secrets to healthier skin, gets up close and personal with some of the most common rashes, spots and blemishes - and shows you how to care for the largest organ in your body. And where better to do that than at the beach? With the help of a team of Australia's top dermatologists we'll find out why skin health is more than a cosmetic issue. We'll learn what we can all do to keep our skin working well for us at any age. We'll find out some surprising facts about moisturiser - and look at how technology is being used to help in the detection and protection against skin cancer. And in the burns unit of ground-breaking Australian surgeon Fiona Wood, we'll meet some of the patients benefiting from her work and find out the latest science around regenerating and protecting skin in trauma.

Lawrence Leung lives a busy life - he's an actor, comedian and a dad to a young daughter. He doesn't always get enough sleep and often wonders if he should be getting more. In this episode of Catalyst, Lawrence explores the latest science behind sleep to find out what he's missing out on - and if he needs it at all. Lawrence meets some of Australia's top sleep scientists as he asks: What is sleep for? When should I go to bed? What happens if I don't sleep? And, how can I sleep better? Along the way he discovers that it's during sleep that the brain chooses which memories to strengthen and which to lose; that extreme sleep deprivation negatively affects a whole range of body functions; and that he should be sleeping more like an elite athlete - and a koala.

Forty-eight-year-old Victoria has chronic anxiety disorder. She's battled this her whole life. But in the past few years she's begun suffering from excruciating gut problems. No-one has been able to provide answers. So, are her gut bacteria the missing link in causing her symptoms? Nutrition scientist Dr Joanna McMillan takes on her most challenging case, exploring emerging science about the links between gut bacteria and the brain to design an intervention to help Victoria where all else has failed. Victoria's struggle is revealing, at time confronting, but above all, inspiring. And the results - astonishing and life-changing.

The race to the moon is back on. Half a century since the last Apollo mission landed on the moon, Alan Duffy takes us inside the new space race, where innovators and big dreamers are rewriting the rule book on space exploration. He witnesses the launch of a new-generation of rocket at Cape Canaveral in Florida. Created by SpaceX, this rocket is partly reusable, and the innovations behind it may help us get back to the moon. Alan meets the pioneers at US's first licenced spaceport in Mojave in California who are building new types of lunar landers and rockets. And he finds out that the discovery of water on the moon may transform our chances of living there and using the moon to explore planets far from home.

There's a tech revolution unfolding in Australia - but it's not happening where you might expect. A team of scientists led by internationally renowned roboticist, Salah Sukkarieh, are opening up a new world of farming science; one that could give Australian farmers more control over their future than ever before. Catalyst joins engineers from the Australian Centre for Field Robotics as they explore the world of agriculture to develop robots and create smarter ways of farming. But are these prototype robots up to the many tasks of a farmer? Will they change the way we've been farming for generations? Can the robots lead the farmers (and their cattle) to greener pastures? Australian farmers are up against it. But help is at hand.

From the science of making choices to the solving power of algorithms, mathematician Lily Serna looks at how the logic of mathematics can help you make better, smarter decisions. In the process she steps us through some of its most important ideas and shows that, far from being stuck on a chalkboard in a lecture hall, it's all incredibly useful.

For the past 35 years, twins have been some of the most carefully studied people in Australia. Seventy-five thousand twins have been revealing the secrets of how much we inherit from our parents and in what ways our experience shapes who we become. Researchers are trying to understand what determines their personalities, makes them succeed at a school or even live longer. It turns out that twins research is confounding simple conclusions about what makes us who we are. We are a complex interplay of genes and environment. In fact revealing the secrets of this extraordinary group of people, may just help all of us live a longer, healthier life.

Gut Revolution seeks to sort the facts from the faeces in an observational series that follows two people with debilitating gut issues on their quest for better health. In part 1, 26-year-old mother-of-two Melissa has been battling a painful case of irritable bowel syndrome for the past two years. She's seen all the doctors and had all the investigations but no-one has been able to help her. Can the latest science driving the Gut Revolution provide any answers? We follow Melissa over her transformational six-week journey as our team of experts design an intervention that literally changes her life.

We all know exercise is good for us. But how many of us really know what kind of exercise we should be doing, how much of it we need, or how hard we should push ourselves? To find the answers, and help all of us live happier, healthier lives, GP Caroline West and cell biologist Shalin Naik are putting their bodies on the line at Australia's toughest athlete training facility: the Australian Institute of Sport. They'll be stealing the latest sports science secrets from the Formula Ones of fitness to help all of us get fitter and stay healthy.

Off Australia's north-east coast lies a wonder of the world; a living structure so big it can be seen from space, more intricate and complex than any city, and so diverse it hosts a third of all fish species in Australia. The Great Barrier Reef as we know it - 8000 years old and home to thousands of marine species - is dying in our lifetime. Can We Save the Reef? is the epic story of Australian and international scientists who are racing to understand our greatest natural wonder, and employing bold new science to save it.

On Friday 15 September, the Cassini spacecraft was intentionally crashed into the planet of Saturn and destroyed. Associate Professor Alan Duffy was on the ground at the Canberra Deep Space Communication Complex to witness the end of this remarkable 20-year mission. Cassini's images and data have changed the way we understand our solar system. Cassini analysed plumes of water that strongly hint at the possibility of life on Saturn's moon, Enceladus. It was this discovery that sealed Cassini's fate - the scientists decided to crash the space probe and its plutonium-powered batteries into Saturn to avoid contaminating Enceladus. Set against the in-the-moment experience of Cassini's controlled demolition is the story of how the mission came to be, thanks to the passion, brilliance and perseverance of some of the planet's greatest space explorers - the men and women of NASA, the European Space Agency and ASI, the Italian Space Agency.

Dr Nikki Stamp takes us into the amazing world of our hearts - revealing how they function, how we can look after them and shows us the latest science she uses to help fix them when they go wrong. Nikki is one of Australia's elite group of female heart surgeons and she passionately believes that many of her patients could have avoided becoming another "heart casualty" - if only she could have shown them earlier how to take care of the one remarkable organ that makes us all tick. She takes us behind the scenes in her operating theatre to give us a privileged look at what happens in these high-stakes operations and we meet the patients who are hoping to have their lives transformed.

A group of world-renowned scientists are on a quest to uncover the secrets of the most significant day in our planet's history: the day that killed the dinosaurs. Sixty-six million years ago an asteroid the size of London hit the planet in the modern-day Gulf of Mexico. Now, as co-leaders of an expedition to drill deep into the Chicxulub asteroid impact crater, Geologists Sean Gulick and Jo Morgan have set out to answer how this resulted in the extinction of dinosaurs.

Will we soon find evidence of alien life? Scientists are currently in the throes of an unprecedented search for ET - and an answer to this long-pondered question may come sooner than you think. Right now researchers are hunting for extra-terrestrial life on several fronts. To find out just how close we might be to a breakthrough, astrophysicist Dr Graham Phillips visits telescopes, swims among the stromatolites on the remote West Australian coastline, and chats with scientists from around the world. He even talks to an eminent astrophysicist who suggests we may have already inadvertently stumbled on evidence of alien mega technology out in space.

Professor Tim Flannery investigates how seaweed is helping to save the world - from growing the foods of the future, helping clean polluted water and even combating climate change. Growing seaweed is now a $10 billion a year global industry. Tim travels to Korea to see some of the biggest seaweed farms in the world and meets the scientists who are hoping to create a seaweed revolution here in Australia.

Imagine you could make a copy of a loved one. A digital clone with a life of its own - their Avatar. That's the dream of biomechanical engineer, Dr Jordan Nguyen, and he says we have the technology to do it right now in the form of virtual reality. VR might be thought as way to play games but as Jordan discovers, it's so much more. VR is being used to face phobias, to combat trauma and in the case of one Newcastle man, Angus, help to re-verse the effects of a catastrophic spinal injury.

Human impacts on the way our planet functions have now become so extreme many scientists are claiming the Earth has shifted out of the Holocene state and into a new geological epoch. They're calling it the Anthropocene, the new age of humans, because millions of years after we are gone, the scar of our existence will be visible in the rocks of tomorrow. In this episode we look at how the past 60 years of socio economic growth has transformed the human race into a geological force to rival nature.

Swift Parrot Update Last year we brought you a story about the swift parrot - one of Australia's most charismatic birds, but also one of its most endangered. Logging and land-clearing have decimated their habitat but conservation biologist Dejan Stojanovic also made the startling discovery of why the parrot numbers were plummeting so rapidly - the deceptively sweet sugar glider was eating them. Mark Horstman returns to Bruny Island in Tasmania to witness their remarkable recovery. Tick Allergy With summer on our doorstep, and the odd barbecue or bush walk planned, we thought it timely to revisit this story: mammalian meat allergy is on the rise in Australia and the surprising cause is a tick bite. Dr Jonica Newby meets Dr Sheryl van Nunen, the clinician who discovered the link, and this story is a must-see if you want the latest tips on how best to remove a tick.

The anecdotal evidence that cannabis has a positive effect on a long list of medical conditions from epilepsy to pain, cancer, even Alzheimer's disease is building. However, to date there's been scant clinical evidence to back up these claims. At long last that may be changing. In this half-hour special, Dr Graham Phillips finds that researchers are now applying scientific rigour to convert anecdote into data and it turns out there could be plenty of promise in this so-called "wonder weed".

Testosterone Testosterone has long been considered the hormone that makes men masculine. But is this common perception selling the hormone short? Dr Graham Phillips investigates. Dr Jane Goodall Profile Meet Dr Jane Goodall DBE, world-renowned primatologist, humanitarian, conservationist and UN Messenger of Peace.

Plain Of Jars The Plain of Jars in central Laos is one of South-East Asia's biggest archaeological enigmas. Ancient, monumental sandstone jars up to 2.5m high dot the landscape in seemingly random patterns. Tiny Satellites Tiny cube satellites revolutionise our access to space. Space has always been the playground of very big players with very deep pockets - but not anymore.

This summer, large parts of the Great Barrier Reef saw the hottest sea temperatures and the most severe coral bleaching ever recorded. So before the next impact hits, scientists are racing against time to understand the demise of reefs and the prospects for their recovery. Catalyst explores the lethal threat of bleaching to the Great Barrier Reef, and the challenges we all face to protect this global treasure.

Forensic Future: Around our country there are human remains sitting at forensic storage sites unidentified but for a case number. They are potentially the loved ones of those still living, but there has been no way of really knowing for sure. Catalyst investigates a real life unsolved mystery of a man who's body has been exhumed from the grave whilst revealing how cutting edge forensics, together with developments in DNA testing are working towards, quite literally, putting a face to the nameless. Alien Megastructure: Something massive, with roughly one thousand times the area of Earth, is blocking the light coming from a star about 1400 light years away, and nobody is quite sure what it is. Without a natural explanation, even the world's most reputable astrophysicists have been forced to consider the possibility of an alien-built megastructure. Such an extraordinary idea would, of course, require extraordinary evidence, which is exactly what we're in search of as we turn our eyes and telescopes towards this perplexing celestial object.

Degas: The National Gallery of Victoria is lined with secrets, but early attempts at solving these mysteries gave only a glimpse of what lay beneath the brushstrokes. We go behind the scenes at the NGV and the Australian Synchrotron to see how scientists are revealing concealed gems with stunning clarity. Out Of Africa Revisit: Last year Catalyst took you on a remarkable road trip through Namibia in Southern Africa, where genomicist Professor Vanessa Hayes collected blood samples to search for the origins of modern society. We revisit this story to find out the results - what she discovered could rewrite human history.

Smell is our most ancient, but also our most underestimated sense. In a recent survey of young adults, just over half said they would rather lose their sense of smell than their access to technology, like laptops or smartphones. In this episode Anja Taylor investigates the hidden powers of smell, and how smell influences many aspects of our lives in ways we often overlook.

The race is on after Scrapboy unveils his latest project: scrapbox racers. Made out of scraps, Scrapboy makes one for Dirtgirl and challenges her to a race around dirtgirlworld.

Test how steady your hand is with an electric game of complete circuitry, create your own construction site built on firm foundations, make a wet and wild water wheel and see what's cooking in our own homemade oven.

Senior ranger Otto Campion Bulmaniya tells the story about how two dreaming serpents rose to stop the cyclone and restore the balance to country.

Kevin Delaney and his team of experts show how explosive hydrogen peroxide can really be. Plus, combining ping pong balls with pressurised liquid nitrogen.

Day 22: after the evacuation due to heavy snow, the remaining seven tribe members continue the experiment. They must preserve and store every last ounce of a deer carcass for the remainder of the five weeks, which causes a disagreement within the group. Leader Steve decides to leave the tribe and Mel steps up but Josie does something inconceivable to JP, making any chance of survival look bleak.

A smart, fun countdown that details how ancient technology worked, how surprisingly advanced it was, and how it was kind of awesome.

We're printing houses, building bridges and constructing wooden skyscrapers in this monumental episode, where the ordinary becomes extraordinary.

One night, once a year, beneath the golden glow of the harvest moon, the most wonderful thing happens in Dirtgirlworld - the creepy crawly concert.

Want a zoo in your backyard? Look no further. We're in the back paddock meeting foals and hitting the aquarium to catch up with a very smart octopus. Plus, playing footy with birds of prey.

HIV/AIDS has claimed around 35 million lives worldwide. But now, as Dr Chris van Tulleken reveals, cutting-edge science can keep the virus at bay or even prevent infection altogether.

Over a thousand years ago a great civilisation built a thriving metropolis in the heart of North America. It was larger than Paris and London at the time and was known as Cahokia. It's one of the best kept secrets of western archaeology, but using cutting-edge technologies, its mysteries are finally unravelled.

How do you make music? How does everyone in an orchestra know when to play? How do you record music? Kellyn, resident scientist Clare and the crew are joined (not live) by Mozart as they answer your questions about music.

The Tasmanian tiger has been extinct since 1936, three intrepid scientists are setting out on a once-in-a-lifetime expedition to explore the possibility that this intriguing animal may still exist.

From the UN Climate conference to the People's Climate March to the forces that deny the science of global climate change, this special extended episode covers all sides of the issue and all corners of the globe, ending with a special interview with former vice-president Joe Biden.

We check out the latest in science and technology. A class attempting a coding record, the latest in spacesuits, an international astronautical conference, plus the huge breakthrough in gravitational waves.

Who makes things we need? How do you make surfboards? How do you build a bus? Kellyn, resident scientist Clare and the crew are joined (not live) by the inventor of the radio, and they uncover how many things are made.

Using cutting-edge technology and a handful of obscure clues from ancient texts, a National Geographic Explorer races to locate Genghis Khan's lost tomb before it is destroyed forever.

Star gazing, gemstones and endangered species - we're uncovering lots of precious treasure. Plus, get not so up close and personal to a rattlesnake, and meet a very fluffy malamute.

Hurricanes, earthquakes, tsunamis, lightning strikes: this program shows what it would be like to experience some of nature's most destructive forces.

Charismatic astronomer Greg Quicke (aka Space Gandalf) takes us on the ultimate guided tour of the southern sky to help reveal unseen connections between the everyday world around us and the stars above.

In a new age of space exploration, some of the boldest efforts at putting humans into space are now those of private companies. Brian Cox goes behind the scenes to explore what is happening in privately financed space flight.

Where does all our rubbish end up? How can food scraps be recycled? Why is composting important? Kellyn, resident scientist Clare and the crew cross (not live) to some space junk and answer all your questions about waste.

Life in the Limpopo River Basin is a fight for survival. It's the brutal dry season, with wildlife awaiting the flood waters. But the rains are late and disaster grips the Valley.

Nabbing a canine culprit with a clever tracking device; stepping into the dark with our feline friends; seeing the colours of the rainbow in bubbles; finding out what makes bread rise; and a spraying fountain made from straws.

Freshwater wetlands and waterholes that are home to a diverse array of birds, insects, fish and crocodiles are spotlighted.