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AST101 Lecture 17 Barsoom AST101 Lecture 17 Barsoom There are 4 Terrestrial Planets • Mercury • Venus • Earth • Mars Mercury From the Messenger Orbiter, March 2011. Rayed crater: Debussy Venus From the Venus Express, 2007. H2SO4 clouds Earth (Terra) Apollo 17 Mars Hubble Space Telescope Barsoom A world like our own? Populated by aliens? Telescopic Observations Mars is dynamic • Polar caps wax and wane • Surface features change shape regularly • Clouds obscure the surface Giovanni Schiaparelli Published a map of Mars in 1877 Identified surface features he called “canali” Schiaparelli’s Mars Percival Lowell Mistranslated “canali” (channels) as canals Established Lowell Observatory on Mars Hill, Flagstaff AZ Lowell’s map of Mars (excerpt) Lowell’s Mars Canals imply • intelligent life, and • deliberate construction Lowell created a Mars that is • a dying planet, • whose intelligent denizens built canals – to collect the melting polar ice, and – to distribute the water among the oases Camille Flammarion (1884) Chesley Bonestell: Surface of Mars © Bonestell Space Art No one would have believed in the last years of the nineteenth century that this world was being watched keenly and closely by intelligences greater than man's and yet as mortal as his own; that as men busied themselves about their various concerns they were scrutinised and studied, perhaps almost as narrowly as a man with a microscope might scrutinise the transient creatures that swarm and multiply in a drop of water. H. G. WELLS THE WAR OF THE WORLDS Illusions of Mars. I. This mythos arose from two optical illusions. 1. The human brain tends to connect the dots, which results in apparent linear features. 2. Dark grey, when viewed next to red, appears green. Mars is not a red planet with green vegetation outlining water canals. Mars is a red planet with dark grey regions. The Dream is Smashed Mariner 4, 1965 Mariner 6, 1967 Mariner 9, 1969 Meridiani Sinus and Rilles in Mare Deucalionis Regio Sirenum Mars Today Valles Marineris and the Tharsis Ridge Schiaparelli Hemisphere Hellas Basin Northern Polar Cap in Spring Olympus Mons Weather Severe Weather A Dust Devil A Frosty Morning In Utopia Planitia July 1976 Viking 2 Roaming on the Surface Dried Riverbeds Snow on Mars Phoenix May 25 2008: Landing on a patch of ice. Sedimentation? Sedi- mentary Rocks Endurance Crater Hematite Concretions Fossil Icebergs? Curiosity on Mars Gale Crater Wall of Gale Crater Science Highlights • NASA Rover Finds Conditions Once Suited for Ancient Life on Mars • NASA Rover Finds Old Streambed on Martian Surface • NASA Rover Finds Clues to Changes in Mars' Atmosphere Illusions of Mars. II. A Face on Mars? The Face on Mars More recent images with better cameras (MGO) More Illusions of Mars Life on Mars today? • There is no macroscopic life • There is no permanently running water • The atmosphere is about 0.001 bar • Mars today is old, cold, and dry Methane on Mars Methane on Mars Meteorites from Mars Are We the Martians? • Mars was more hospitable to life early on • Mars had a significant atmosphere and surface water • Earth took longer to develop a solid surface • How did microbial life evolve on Earth a mere 200 million years after the Earth's surface solidified? • Perhaps life evolved on Mars, and was carried to Earth on meteorites .
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