We once thought that our solar system was unique: The only place you could find planets in the entire Universe. Now we know better. For the last twenty years we have been discovering planets at an amazing rate, but they are nothing like we expected. These are truly wild worlds, a collection of monsters. From deep-frozen, toxic snowballs, to scorched and boiling nightmares: Every one is worlds apart from the habitable paradise we know and love here on Earth. Having so far only discovered this zoo of planetary oddballs we must face the question: Is every planet out there a planet from hell?
Even with a surface temperature of -180C, Saturn's moon, Titan, could be another Earth. There's evidence of dunes made of quantities of organic material that could contain the building blocks for DNA. Astrobiologists are conducting studies on the possibility that life could be present on Titan.
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).
When Neil Armstrong stepped onto the moon in 1969, America went down in popular history as the winner of the space race. But that history is bunk. The real pioneers of space exploration were the Soviet cosmonauts. This documentary combines rare and unseen archive footage with interviews with the surviving cosmonauts to tell the fascinating and at times terrifying story of how the Russians led us into the space age. A particular highlight is Alexei Leonov, the man who performed the first spacewalk, explaining how he found himself trapped outside his spacecraft 500 miles above the Earth.
2014 • Astronomy