Meet Perseverance, NASA's latest rover, as it heads to Mars to answer one question: did life exist on the red planet? On the way, it will lay the foundation for human exploration of our closest neighbour. Today, Mars is hostile to life. It's too cold for water to stay liquid on the surface, and the thin atmosphere lets through high levels of radiation, potentially sterilizing the upper part of the soil. But it wasn't always like this. Some 3.5 billion years ago or more, water was flowing on the surface. It carved channels still visible today and pooled in impact craters. A thicker carbon dioxide atmosphere would have blocked more of the harmful radiation. The Mars 2020/Perseverance rover is designed to better understand the geology of Mars and seek signs of ancient life. The mission will collect and store a set of rock and soil samples that could be returned to Earth in the future. It will also test new technology to benefit future robotic and human exploration of Mars, as the Ingenuity Helicopter.
April 1453. Sultan Mehmed II unleashes an artillery attack on Constantinople unlike any the world has ever known. It's the largest concentration of cannons that the world had seen in one place. The monumental task of keeping the Ottomans out of Constantinople falls on the shoulders of Genoese soldier of fortune Giovanni Giustiniani. He and his men must defend 14 miles of city walls. Mehmed launches his ambitious plans to break through the walls of Constantinople, but Giustiniani's mercenaries manage to forestall the attacks.
In these extraordinary times, there is one thing that can offer solace to everyone – the wonder of the natural world. In the most extreme of environments, from the hottest deserts to the freezing poles, from the highest mountains to underwater kingdoms, animals overcome adversity to survive and thrive, offering a message of hope to humanity. To raise our spirits, David Attenborough, Hans Zimmer and Dave unite for a special Natural History event – Planet Earth: A Celebration. The special one-hour programme brings together eight of the most extraordinary sequences from Planet Earth II and Blue Planet II including racer snakes vs iguana, surfing bottlenose dolphins and rare footage of the Himalayan snow leopard.
Sultan Mehmed II's siege of Constantinople enters its third week. Mehmed's artillery teams continue their relentless bombardment of Constantinople's walls. After his navy suffers a devastating defeat, Mehmed moves his ships overland to the Golden Horn in a daring, visionary feat. In the shadow of betrayal, Giustiniani attacks the Ottoman fleet.
In a provocative documentary, environmental campaigner George Monbiot examines the disastrous impact that farming animals for meat has had on the planet. He argues that the biggest problem driving us towards global disaster is how we feed ourselves, particularly on meat George looks at alternative food sources, including synthetic meat, and a process that produces protein from just bacteria and air, and also explores revolutionary ideas that could change agriculture as we know it.
Today, Mars is hostile to life. It's too cold for water to stay liquid on the surface, and the thin atmosphere lets through high levels of radiation, potentially sterilizing the upper part of the soil. But it wasn't always like this. Some 3.5 billion years ago or more, water was flowing on the surface. It carved channels still visible today and pooled in impact craters. A thicker carbon dioxide atmosphere would have blocked more of the harmful radiation. The Mars 2020/Perseverance rover is designed to better understand the geology of Mars and seek signs of ancient life. The mission will collect and store a set of rock and soil samples that could be returned to Earth in the future. It will also test new technology to benefit future robotic and human exploration of Mars, as the Ingenuity Helicopter.