The attempt to send and land astronauts on Mars risks billions of dollars and the lives of those brave enough to attempt it. Is the possible benefit really worth the risk? And is it really achievable? Guiding us through this ethical and scientific minefield is Dr Kevin Fong. Kevin's diverse background in astrophysics, aeronautics and medicine makes him uniquely placed to understand the technical and human challenges of this perilous journey. With the help of the BBC's rich archive and a cast of supporting experts, Kevin leads us through the journey to Mars stage by stage. For Kevin, not only is this the toughest journey we will ever attempt, it is one that he feels we ultimately must make if we are to survive as a species.
Almost everything we know today about the beautiful giant ringed planet comes from Cassini, the NASA mission that launched in 1997 and arrived at Saturn in 2004. Since then, the space probe has been beaming home miraculous images and scientific data, revealing countless wonders about the planet, its rings and 62 moons - including some that could harbor life. As the mission approaches its final days in 2017, it attempts one last set of daring maneuvers - diving between the innermost ring and the top of Saturn's atmosphere. Aiming to skim less than 2000 miles above the cloud tops, no spacecraft has ever gone so close to Saturn, and hopes are high for incredible observations that could solve major mysteries about the planet's core. But such a daring maneuver comes with many risks and is no slam dunk. In fact, slamming into rocks in the rings is a real possibility. Join NASA engineers for the tense and triumphant moments as they find out if their bold re-programming has worked, and discover the wonders that Cassini has revealed over the years.
Scientists have started looking to the heavens and wondering what the weather might be like on other planets. Today, we are witnessing the birth of extra-terrestrial meteorology. They began with our solar system, sending spacecraft to explore its furthest reaches, and now the latest telescopes are enabling astronomers to study planets further afield. Our exploration of the universe is revealing alien worlds with gigantic storm systems that encircle entire planets, supersonic winds and extreme temperatures. On some planets, temperatures are so hot that the clouds and rain are believed to be made of liquid lava droplets, and on other planets it is thought to rain precious stones. We thought we had extreme weather on Earth, but it turns out that it is nothing compared to what's out there.
Astronaut Mike Massimino reveals the mysterious secrets of Saturn and its rings; using the latest science from the Cassini mission, he explores the planet's giant icy geysers, powerful hurricanes, and moon that may be hiding extraterrestrial life.
A billion miles from home, running low on fuel, and almost out of time. After 13 years traversing the Saturn system, the spacecraft Cassini is plunging to a fiery death, becoming part of the very planet it has been exploring. As it embarks on its final assignment - a one-way trip into the heart of Saturn - Horizon celebrates the incredible achievements and discoveries of a mission that has changed the way we see the solar system. Strange new worlds with gigantic ice geysers, hidden underground oceans that could harbour life and a brand new moon coalescing in Saturn's magnificent rings. As the world says goodbye to the great explorer Cassini, Horizon will be there for with a ringside seat for its final moments.
Carl Sagan teaches students in a classroom in his childhood home in Brooklyn, New York, which leads into a history of the different mythologies about stars and the gradual revelation of their true nature. In ancient Greece, some philosophers (Aristarchus of Samos, Thales of Miletus, Anaximander, Theodorus of Samos, Empedocles, Democritus) freely pursue scientific knowledge, while others (Plato, Aristotle, and the Pythagoreans) advocate slavery and epistemic secrecy.