The history of Mars - Carl Sagan's 1977 Christmas Lectures 3/6

In the third of his Christmas lectures, Carl Sagan explores the mystery of the Red Planet. Watch all six lectures from this series here: The Planets - Carl Sagan's 1977 Christmas ... Watch our newest Christmas lectures here: Royal Institution Christmas Lectures This lecture was recorded at the Ri on 3 December 1977. --- Cold, arid, and tens of millions of miles away from Earth, Mars has intrigued scientists for centuries. The existence of liquid on its surface was confirmed by NASA’s flyby mission, Mariner 4, in 1965, but the question of whether life exists on our neighbouring planet has remained a subject of much speculation. In the 19th and 20th centuries, observers using only the naked eye and a telescope saw features on Mars which they interpreted as evidence for a dry but Earth-like climate, for vegetation which grew and decayed with the seasons, and for a great Martian canal network designed by a heroic but dying race of hydraulic engineers. From its rocky craters to its polar ice caps, Carl describes our understanding of the geology and chemistry of Mars, revealing the discovery of its two moons, Phobos and Deimos, in 1877, and the bizarre one-time suggestion that these moons were artificial satellites launched by an ancient but not extinct Martian civilisation. --- CARL SAGAN'S 1977 CHRISTMAS LECTURES: What exists beyond Earth? Over six Lectures presented in 1977, American astronomer and cosmologist Carl Sagan explores the vast expanse of space that surrounds the third planet from the Sun. Life on Earth Where at first we could only discern the size of our planet and some knowledge of its atmosphere and configuration, the evolution of planetary exploration has revealed not only intricate details of Earth’s climate and geology, but a multitude of stars and planets besides our own. Beginning with a closer look at the world we inhabit, Carl explores of the diversity of life on our own planet and the building blocks behind it, before questioning whether the same organic chemistry is occurring on planets in the outer solar system. The Red Planet In Lecture three onwards, Carl takes a closer look at our neighbouring planet, Mars. From early interpretations of terrestrial life on its surface to the surprising discoveries made by NASA’s Viking Program, the Red Planet has become the focus of efforts to discern whether intelligent life exists elsewhere in the universe. When Carl delivered his Lectures in the late 1970s, NASA had only just begun its Voyager program to the furthest planets in our solar system and no extra-solar planets were known to exist. Now, over three decades later, astronomers are looking at planets that lie beyond our solar system to ask the very same question we pondered over Mars: is there life out there? ---- ABOUT THE CHRISTMAS LECTURES: Set up by Michael Faraday when organised education for children was scarce, the Royal Institution CHRISTMAS LECTURES established an exciting new way of presenting science to young people. World-famous scientists have given the Lectures, including Nobel Prize winners William and Lawrence Bragg, Sir David Attenborough, Carl Sagan and Dame Nancy Rothwell. First broadcast in 1936, the CHRISTMAS LECTURES is the oldest science television series. They have been broadcast every year since 1966 on the BBC and in later years on Channel Five, Channel Four and more4. In 2010, the Lectures returned to BBC Four, and this year were shown on the 26th, 27th and 28th of December. Find out more about the lectures here: https://www.rigb.org/christmas-lectures ---- The Ri is on Twitter: Twitter: ri_science and Facebook: Facebook: royalinstitution and TikTok: TikTok: ri_science Listen to the Ri podcast: https://podcasters.spotify.com/pod/sh... Donate to the RI and help us bring you more lectures: https://www.rigb.org/support-us/donat... Our editorial policy: https://www.rigb.org/editing-ri-talks... Subscribe for the latest science videos: http://bit.ly/RiNewsletter Product links on this page may be affiliate links which means it won't cost you any extra but we may earn a small commission if you decide to purchase through the link. #MarsHistory, #CarlSaganLectures, #1977ChristmasLectures, #SpaceExploration, #HistoryOfMars