Early ExplorationViking “The scientific goal of the Viking missions is to ‘increase

our knowledge of the planet Mars with an emphasis on the search for extra-terrestrial life.’ The scientific questions deal with the atmosphere, the surface, the planetary body, and the question of bio-organic evolution.”

Viking Press Kit, July 1975

Early ExplorationViking

Get down and get dirty.

Early ExplorationVikingThe primary mission objectives were to:

Obtain high resolution images of the Martian surface Characterize the structure and composition of the

atmosphere and surface and Search for evidence of life

Twin orbiter/lander combo

Early ExplorationVikingOrbiter instruments

Visual Imaging Subsystem – two cameras; each a telescope with a camera head (124 ft/px); could resolve objects the size of a football field

IR Thermal (temperature) Mapper Mars Atmospheric Water Detector “Again a question: Are we now seeing the last disappearing

remnants of water that was once much more plentiful on the planet, or is Mars locked in an ice age that has frozen out most of its water in the polar caps or beneath a layer of surface dust?”

Early ExplorationVikingLander instruments

Two panoramic cameras Sampler arm Meteorology boom w/ temperature, wind direction and

velocity sensors Seismometer Biology experiment Gas chromatograph mass spectrometer X-ray fluorescence spectrometer More info on each instrument can be found at:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19750018961_1975018961.pdf

Early ExplorationVikingV1 Launched August 20, 1975; arrived at Mars June 19,

1976Devoted first month to searching for landing sites for the

lander; V1 lander touched down July 20, 1976 in Chryse Planitia

Early ExplorationVikingV2 launched September 9, 1975, arrived at Mars on

August 7, 1976First month devoted to searching for a landing site; V2

touched down September 3, 1976 in Utopia PlanitiaOne leg landed on a rock; tilted 8.2°

Early ExplorationVikingWith landers on the ground, orbiters continued science

mission above and acted as data relays for landers

Early ExplorationVikingNotable results from Viking orbiters:

Mapped 97% of the surface; 52,000 total imagesDefinitively determined the North residual polar cap is

water-ice, not frozen carbon dioxideAtmospheric pressure varies by 30% during the Martian

year due to sublimation and condensing of CO2 at the poles

Stirred up a little “controversy” with one particular image

Early ExplorationViking

Early ExplorationVikingNotable results from Viking landers:

Biology experiments provided no clear evidence for the presence of living organisms in soil near the landing sites

Gas Chromatograph/Mass Spectrometer found no evidence of organic material at either landing site

Winds blew more slowly than anticipated (200 MPH); highest recorded wind gust was 120 km/hr (74 mph) and average velocities were much lower

Weather in the Martian midsummer was repetitious but was variable and more interesting in other seasons

Early ExplorationVikingHow did Viking advance scientific understanding of Mars?

Difficult for life to exist on the surface at present, but this does not rule out past life

More evidence for past habitability Weather patterns Though no current life, Mars is a dynamic planet

What technological advance(s) did Viking carry? LANDER!! Higher res. Cameras Weather station Biology experiments Orbiter comms. relay, selective landing sites