Space science : Mars, new laboratory for science (1980)

at sea buggy research scientists create products which enrich the quality of our lives products to increase our food supply dyes and pigments which surround us with color pharmaceuticals to improve our health products which reaffirm the value of science to mankind as part of its continuing program in support of Science Education ciba-geigy is pleased to present this issue of the science screen report the science screen report developments in science engineering and medicine that help solve the problems of modern life [Music] since antiquity people have speculated about Mars was it a world of colossal canals advanced civilizations mysterious aliens prolonged telescopic studies gathered few facts Mars was half the size of Earth at a 24-hour day displayed seasonal feature changes but otherwise remained a near-total mystery [Music] it was only with the Viking mission to Mars that scientists began to actively probe this strange world today Mars has become a planetary laboratory for studying soil chemistry geology biology weather climate and other processes much resembling yet very different from those on earth [Music] [Music] the first space probes of the planet Mars were made in the 1960s when three Mariner spacecraft flew past photographing about 10% of the surface [Music] in 1971 the Mariner 9 spacecraft orbited Mars transmitting more than 7,000 photographs to earth mapping nearly the entire planet and revealing unexpected topographical features in 1975 two Viking spacecraft each carrying a lander robot went into orbit around Mars to study and probe the still mysterious world once in orbit the Vikings were used for a detailed examination of possible landing zones the final choice a flat expanse with few impact craters [Music] July 20th 1976 Lander 1 separates and begins its descent the robot about the size of a large motorcycle controls its own flight entering the thin carbon dioxide atmosphere its instruments continuously analyze and kilometer to earth data on the Martian environment this film material of the first successful Mars landing was provided by the National Aeronautics and Space Agency seconds after landing the biking camera returns the first surfaced picture the robot's foot pad set firmly on another world the second picture a long panorama of the landing site rocks and volcanic material to one side sand and dune fields on the other the first color picture find us red or yellow brown covers the surface the sky is a lighter tint due to suspended dust particles soon after the second landing is accomplished on a vast plane again littered with rubble typical of meteor impacts and volcanic eruptions as the landers begin their programmes of experiments the orbiters continue mapping surface topography weather variations and other data for several years now the robots of the Viking mission have continued to gather data from the Martian environment this planetary survey is scheduled to continue through 1990 providing a 15-year study of the planet Mars [Music] meanwhile the tens of thousands of photographs and other data transmitted have been used to profile the forces and processes that shape the planet keys to better understanding their counterparts on earth the record of meteor impacts has been used to reconstruct Mars geological history the older the formation the more meteors have struck [Music] here a small fresh crater over lies a larger older one on the left a crater rim has eroded away and here a fresh crater is a cluster of crater rims buried by some later event Mars apparently was formed about four and a half billion years ago in the swirling gas and dust nebula that also gave rise to the Sun and Earth in this process heat was released as one result the heavier material settled to the center the whiter substances rose to form a planetary crust as elsewhere in the solar system meteor bombardment then excavated craters and immense basins much of Mars surface like the moon's is still cratered but elsewhere volcanic action commenced raising mountains lava flows built shield volcanoes the greatest Olympus Mons is 27 kilometers high and 600 across wide enough to cover the Hawaiian Islands crustal expansion led to faulting an drifting one Rift Valley is 5,000 kilometers long perhaps the start of continental drift on Mars Mars surface was also shaped by water experts believe that during the first billion years of Mars history the atmosphere may have been warm and dense enough for rains to fall and rivers to flow channels formed by those primordial rainstorms were evident in several Viking photographs in addition molten rock intruding into crustal ice may have formed slurries mixtures of water dust and rock that moved across the surface such slurry movements could explain the large channel systems extending hundreds of kilometers with their teardrop shaped islands features with no counterparts on our earth on Mars low atmospheric pressures and temperatures do not allow liquid water to exist the northern polar cap is thought to be made up of water ice mixed with dust in addition water vapor measurements indicate a vast reserve of subsurface permafrost [Music] nearer the Martian equator thin clouds of condensed water vapors swirl around volcanoes or drift high in the sky [Music] while in canyons and valleys a morning ice haze as recorded by the cameras in orbit on earth the oceans heat and moisture together with heat and wind variations over land produce our complex weather patterns on Mars because there are no water masses or cloud formations there is little variation in the weather only an early summer does solar heating produce violent dust storms driven by hurricane-force winds they may blanket the entire planet streaks associated with craters are due to winds light streaks to dust deposits Dark One's uncovered solid surface the spiral formations at the poles exemplify Martian chemical physical and geological variations the dark bands are scarps or cliffs of bare ground within the polar cap each scarf holds terraces eroded from surface rock this is a model of such an area about 75 kilometers across it is thought that scarps and terraces were formed at the same time but by different geological processes because of the planet's orbit and axial tilt polar regions are alternately warm then cold for hundreds of thousands or perhaps millions of years during cold periods mixtures of dust and ice were deposited in near horizontal layers a period of warmer climate followed and erosion processes set in cutting deep valleys new ice dust mixture layers were laid down and more erosion followed this cutting off of one set of terraces by the next is evidence for millennia long climatic cycles the first climatic process discovered beyond planet Earth [Music] questions about life on Mars have not been resolved at the time life first developed on earth several billion years ago the two planets were very similar suggesting Martian life as depicted here might resemble earth life on Earth life interacts with the environment most living organisms take in oxygen and release carbon dioxide while Photosynth the plants take in carbon dioxide and release oxygen seeking evidence of such life the Viking Lander robots carried out tests to detect these processes first results seem to be positive but later analysis suggested these were due to chemical not biological activity any biological process depends on organic compounds so next tests were made on earth to learn if organic compounds could form under Martian conditions an artificial Mars environment was created finely ground simulated Mars surface material plus traces of water a low pressure carbon monoxide Mars atmosphere tagged with radioactive tracers and Martian sunlight from a xenon arc lamp as the result of the experiment traces of organic compounds appear to have been synthesized [Music] but Vikings instruments failed to detect organic compounds this fact decreases the chances that life exists on Mars yet since only three tests were made at only two sites experts still cannot rule out life on that planet meanwhile research is underway to further investigate Viking soil chemistry results and their relationship to possible life on Mars extraterrestrial life is only one of the questions facing today's space scientists they also probe the origin and evolution of the solar system of our own planet and of our own species the search for new knowledge is the goal of planetary exploration and the voyages of our spacecraft across the solar system are beginning to provide some of the answers we seek [Music] [Music] science screen report has been produced by ciba-geigy corporation with headquarters in Ardsley New York as part of its continuing program in support of science education [Music]