This is the epic story of the stars, and how discovering their tale has transformed our own understanding of the universe. Once we thought the sun and stars were gods and giants. Now we know, in a way, our instincts were right. The stars do all have their own characters, histories and role in the cosmos. Not least, they played a vital part in creating us. There are old, bloated red giants, capable of gobbling up planets in their orbit; explosive deaths - supernovae - that forge the building blocks of life; and black holes, the most mysterious stellar tombstones. And, of course, stars in their prime, like our own sun. Leading astronomers reveal how the grandest drama on tonight is the one playing above our heads.
Dark matter is the biggest mystery of the cosmos. Scientists know that it has been vital to the universe since its birth, and new discoveries reveal that it could create black holes, cause mass extinctions, and might even shape life on Earth itself.
What if you could get behind the wheel and race through space? We scale down the Solar System to the continental United States and place the planets along the way to better appreciate the immense scale of the Universe. See space as never before, with Mars looming over the Freedom Tower and Jupiter towering above the Lincoln Memorial. Join former astronaut Chris Hadfield - a YouTube sensation for his performance of David Bowie’s “Space Oddity” aboard the International Space Station - and his interstellar hitchhikers Michio Kaku and astronomers Derrick Pitts and Laura Danly. It’s a joyride from coast to coast - and from the sun to Pluto.
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).
Questions are raised about the search for intelligent life beyond the Earth, with UFOs and other close encounters refuted in favor of communications through SETI and radio telescope such as the Arecibo Observatory. The probability of technically advanced civilizations existing elsewhere in the Milky Way is interpreted using the Drake equation and a future hypothetical Encyclopedia Galactica is discussed as a repository of information about other worlds in the galaxy. The Cosmos Update notes that there have been fewer sightings of UFOs and more stories of abductions, while mentioning the META scanning the skies for signals.
Second Genesis follows planetary scientist Carolyn Porco as she explores what it takes to look for life beyond Earth, and what conditions are required for life to exist. Porco makes the case that Saturn’s moon Enceladus—with its plumes of water vapor spewing into space, confirmed organic materials, and evidence of hydrothermal vents at the bottom of its liquid ocean—is the most promising place to look. Could Enceladus be the key to proving once and for all that life is not unique to Earth? And what it would mean—both scientifically, and spiritually—if we found evidence of a true second genesis right here in our own galactic back yard?
2017 • Astronomy