1In Search of Life on MarsASTR 111Fall 2004by Prof GellerWhat I’ll Talk AboutSome historya view at the start of the 20th centuryMariners to MarsViking Missionin search of life of MarsA meteoritein search of life in a rockSome latest views from MarsConclusionskeeping it simpleThe High Hopes“The planet Mars, on the other hand, exhibits in the clearest manner the traces of adaptation to the wants of living beings such as we are acquainted with. Processes are at work out yonder in space which appear utterly useless, a real waste of Nature’s energies, unless, like their correlatives on earth, they subserve the wants of organized beings.” [Richard Proctor, 1902]2From Schiaparelli… As seen by telescopes from EarthAn orange-red orb, with some darker patches and bright polar caps sometimes visible Giovanni VirginioSchiaparelli (1835-1910)1876 announced discovery of “canali” (channels) on Marsmisreported as canals (artificial) by the pressTo Percival LowellPercival Lowell (1855-1916)appointed MIT astronomy professor in 1902published books⌧Mars (1895)⌧Mars and its Canals (1906)⌧Mars as the Abode of Life (1908)Lowell’s Observations and Explanation•No canals• human brain tendencies• connect unrelated points together by lines• Recent theory• Lowell’s telescope acted as an ophthalmoscope• caused Lowell to see the reflection of the radial pattern of his own retinal blood vessels3More Historical Background At the turn of the 20th century:publication offered a reward for anyone coming forth with proof of life on another planet or anywhere in space EXCEPTING Marsjust about every major observatory had released hand paintings of Mars and some were even releasing photographs as astrophotography was in its infancy⌧no two drawings could agree on the formations on the planet's surface⌧they showed a Mars with a varied surface possessing darker and lighter areas, as well as the polar capsMariner 4, 6 and 7Mariner 4Mars flyby missionclosest approach came on July 15, 1965pictures from this mission showed no canals and a surface that was disappointingly looking like that of the moon, quite LIFELESSIn 1969 the United States launched Mariner 6 (February) and Mariner 7 (March)At closest approach (July for Mariner 6 and August for Mariner 7) both craft were at a distance of approximately 3400 kilometersMariner 4 Photographs4Mariners 6 and 7The Mariners (6 & 7) contained:narrow and wide angle camerasinfra-red radiometerinfra-red spectrometerultra-violet spectrometerTemperature, pressure and atmospheric constituents were analyzedPictures were still anything but spectacularA Time to Fail and SucceedIn 1969two unsuccessful attempts by the RussiansIn 1971both Americans and Russians had unsuccessful missions to MarsRussian Mars 2 and Mars 3⌧both equipped with lander modules but neither lander was successfulAmericans Mariner 9⌧reached Mars during a global dust storm• the storm did eventually subside and the mission was enough of a success so as to provide pictures for the choosing of a site for landing the upcoming Viking missionsMariner’s AtmosphereFirst look provided by Mariner spacecraftMariner 9 specifically⌧faced presence of a global dust storm⌧illustrated the progress of a feature that looked very much like a terrestrial cold front, visible as a bright band extending across many of the images⌧saw evidence of dust storm associated with strong winds⌧saw large crater rim produce wave clouds, believed to be composed of water ice (resembling "sonic boom shock wave”) produced by strong low level winds passing over the crater⌧saw day-to-day variations indicative of day-to-day weather changes and frontal systems5Mariner 9 PhotographsA Prelude to Viking First approved in December of 1968 for a 1973 launch Launch date postponed due to Congressional funding cutbacks Idea was to launch the craft in 1975 for a landing to take place on Independence Day in 1976 Viking 1 was to be launched on August 11, 1975 but was postponed due to a malfunction While fashioning repairs for the spacecraft, the twin unit was substituted and so Viking 2 became Viking 1 and vice versaViking LiftoffViking 1 launched August 20, 1975Viking 2 launched September 9, 1975Each Viking orbiter consisted of:television camera systeman atmospheric water detectoran infra-red thermal mapper6Viking InstrumentsEach Viking lander contained:television camera systemgas chromatograph mass spectrometerx-ray fluorescence spectrometerseismometerbiology labweather stationsampler armEach aeroshell contained:a retarding potential analyzerupper-atmosphere mass spectrometerArrival at MarsViking 1 arrived at Mars on June 19,1976took pictures to aid in the choice of a landing site for the lander⌧caused a delay in the landing beyond its Independence Day rendezvousUsing the latest pictures, the western slopes of Chryse Planitia were selected for the landing of Viking Lander 1Another Giant Leap for MankindOn July 20, 1976 (seven years after a man had taken his first steps on the moon)Viking Lander I successfully descended upon the soil of Mars⌧immediately after successful touchdown, the lander had instructions for taking pictures with its camera (there was actually a concern that the lander might sink into the soil, and so at least a picture was desired before it conceivably had sunken)7The Viking LookThe Viking camerasnot cameras in the conventional senseeach consisted of:⌧a nodding mirror⌧a rotating turret which caused the images to be reflected down to the photodiode, which built up a picture as a series of pixels from each scan of the mirror and rotation of the turretcriticized for its inability to detect any moving objects (some still felt it possible that there might be macroscopic creatures on the planet)Viking Orbiter PhotographThe Face on Mars8The Face on Mars - Caption The picture shows eroded mesa-like landforms. The huge rock formation in the center, which resembles a human head, is formed by shadows giving the illusion of eyes, nose and mouth. The feature is 1.5 kilometers (one mile) across, with the sun angle at approximately 20 degrees. The speckled appearance of the image is due to bit errors, emphasized by enlargement of the photo. The picture was taken on July 25 from
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