An asteroid colliding with the Earth is not a just Hollywood fantasy. NASA and the Space Guard Foundation develop deflection plans to save the Earth from a comet, meteor or asteroid with Earth in its trajectory. Take a look at how the world is working together to keep our skies safe.
In 1972, the crew of Apollo 17 captured the iconic 'Blue Marble': the first photograph ever taken by an astronaut of the entire Earth. This photo had a profound effect on our perception of ourselves. Since then, Nasa has taken millions more. In this epic, powerful and revelatory documentary, a new generation of astronauts, including Tim Peake, use those images of the Earth from space to reveal the astonishing transformation humanity has wrought in the 45 years since 'Blue Marble'. Together, the astronauts provide an armchair tour of the change they've witnessed from orbit, as humankind etches our presence on the planet. Using stunning time-lapse sequences, the programme reveals how we are reshaping our world, for better and for worse: from the sprawling megacities of China to vast desert farms in the Middle East and from the melting snowcap of Kilimanjaro to giant solar arrays in Nevada.
2017 • Astronomy
Sagan discusses the story of the Heike crab and artificial selection of crabs resembling samurai warriors, as an opening into a larger discussion of evolution through natural selection (and the pitfalls of intelligent design). Among the topics are the development of life on the Cosmic Calendar and the Cambrian explosion; the function of DNA in growth; genetic replication, repairs, and mutation; the common biochemistry of terrestrial organisms; the creation of the molecules of life in the Miller-Urey experiment; and speculation on alien life (such as life in Jupiter's clouds). In the Cosmos Update ten years later, Sagan remarks on RNA also controlling chemical reactions and reproducing itself and the different roles of comets (potentially carrying organic molecules or causing the Cretaceous–Paleogene extinction event).