NATS 1880 Lecture Notes - Lecture 8: Tharsis, Mantle Plume, Percival Lowell
25 Jun 2017
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William herschel: 1784, observed mars & claimed martian civilization. Giovanni schiaparelli: 1877, 79 canals observed on mars (canali due to sand storms)* Percival lowell: 1894 observed 200+ canals & claimed of martian civilization. Alfred russel wallace: 1907, denied lowell"s claims - being that they were fantasies, and just contours of features on mars (which they were) Nasa"s mariner 4: 1965 - craters, not canals, & cold, dry planet unsuitable for life. Viking 1&2: 1976 - probe & lander found no life (stopped exploration for 20 years) Path nder: 1997 lander & rover checked chemical composition of rocks. No ozone/atmosphere (95% co2) = harsh uv radiation at surface = desert like. No magnetosphere: high energy particles hit the surface* No atmosphere = sun"s damaging rays pass onto surface. Liquid water: too cold & pressure too low the water would evaporate. Twice as long since the year is twice as long.
