Planet Mars: 1979

of all the planets in the solar system earth in Mars the third and fourth planets from the Sun are the most similar but despite the similarities Mars is essentially like no other planet it is a unique world it was an elusive and baffling planet to astronomers for hundreds of years who early telescopes had appeared to be a small red sphere later estimated to be about half the size of Earth one of the earliest known representations of the planet drawn in 1659 indicated markings on the surface and by the movement of these dark patches that cost the disk it was shown that Mars rotated on its axis in a period only a little longer than it's about 24 and 1/2 hours it was observed too that the tilt of its axis like the Earth's exposes its polar regions alternately to the sunlight thus each hemisphere has a summer and winter period and since Mars orbits the Sun in 687 Earth days one Martian year and each of its seasons is almost twice as long as Earth's later nettings of the planet displayed light and dark regions identified erroneously as continents and oceans the landmass is red as the sandstone districts on earth the water a greenish blue in 1877 an Italian astronomer Giovanni Schiaparelli mr. Byrd what he called canal a or channels resembling he said the finest threads of a spider's web drawn across the disk in America Percival Lowell founded an observatory to study these Martian features massive irrigation systems he called them designed to carry water from the melting IceCaps to the major centers of a civilization science fiction writers populated the cities the terrible creatures of heroic science with skills beyond earth man's dreams in the 1960s three Mariner spacecraft flew by Mars and photographed about 10% of the surface yawn with the ten hours down with the city gone a brilliant and sinister Martian the photographs revealed a cratered landscape much like the moon waterless an apparently hostile to life but in 1971 the Mariner 9 spacecraft orbited Mars and transmitted more than 7,000 photographs of the planet to earth the extensive mapping revealed a new and unexpected world a southern hemisphere seen by earlier spacecraft flattened and gouged by the impact of meteorites the northern hemisphere a vast plain with few craters and rising from the plane a great dome called Tarsus topped by giant volcanoes the plateau that joins the two hemispheres is cut by a vast and deep canyon and by channels were the characteristic patterns of stream beds on earth some of the channels suggest that that water may want to flow down Mars and thus life might have evolved and possibly adapted to Mars changing conditions and then in 1975 two Viking spacecraft were launched each of which was programmed to land a robot on the Martian surface one of its principal objectives was to test for the presence or absence of living organisms a communication system linked a spacecraft to the Mission Control and computing center the in Pasadena California on June 19th 1976 the first Viking arrived in the vicinity of Mars after a year-long journey of more than 400 million miles once in orbit its cameras were turned to a detailed examination of the landing area imaging teams on earth scanned some 800 photographs covering a territory about the size of Texas the chosen landing site was a fat expense for the few impact craters one of the lowest regions on the surface on July 25 1976 flight controllers ordered the lander to separate from the orbiter returns of Mars great distance America the signal traveling at the speed of light 186,000 miles per second took 19 minutes to reach the spacecraft this necessitated a completely automated system onboard for carrying out the landing maneuver during the Landers descent its instruments analyzed the properties of the thin Martian atmosphere good roll attitude hold most water by fire water fire I got what if to sing just playing this 105 on that freezing thing come on I'm freezing make a boy 1,400 feet hundred seventy seven feet per second forever parachute separation - 105 2300 2,600 feet ACS is close to vertical yes we have touchdown towers one cracking job very well done outstanding great navigation perfect I'm assuming that we must be sitting right on the X so that's the smooth area so everybody just did fabulous and couldn't be more pleased thank you 25 seconds after landing one of the two cameras was initiated in scan the first picture of the Martian surface about a half an hour later when it started to come back from the orbiter and we got the first seven lines on the TV monitors you could see gray and white light levels and we knew there was something there and all of a sudden we were looking at the surface of Mars and it was clear it wasn't dusty it was sharp and when we got to the end of that first picture with the dust and small pebbles in the footpad it was just it was really a miracle in an instant the picture was wiped off the TV monitors and behind it came the filling in of the second picture a long panoramic view that covers 300 degrees and extends from the lander to the horizon it disclosed a sector of the basin called crisi Phoenicia covered with sand or dust and littered with rocks the following day Viking setback the first color picture a fine dust red or yellow brown covers the ground the sky is a light hint of the same color due to the particles of dust suspended in the air 45 days after these historic events Viking 2 landed at an area 4,600 miles northwest of Viking one's landing site a vast pane littered - with rocks resembling those on earth produced by volcanic processes or by meteorite impact while the Landers conducted experiments on the surface the orbiters swinging around the planet measured variations in moisture and temperature and took high-resolution photographs of the Martian terrain all and a half billion years ago the planets were formed from the gas and dust of the solar nebula in the formation of a planet heat his release the remains embedded in the growing mass because the heat can't escape as rapidly as the mass is growing a point is reached eventually for the interior melts on Mars the heavier material sank for the center and the lighter material rose to form a crust of the surface and this crust contained ice and other condensates a later stage may have occurred where molten rock intruded into the crust and melted the ice causing a slurry of water and rock and duct to flow across the surface some observers believed that such a process may have been the cause of the major channels which we see on the surface of Mars today but others believe that in Mars first billion years the atmosphere may have been warm and dense enough for rain to fall and for rivers to flow gradually the original thick wet and warm blanket of the atmosphere evolved into the thin dry carbon dioxide atmosphere we find there today because of Mars low atmospheric pressure and low temperatures water can't exist in liquid form it must either freeze or evaporate but while there are no oceans or rivers on Mars there is more water in total than anyone had expected the residual polar cap in the north which remains after the hottest part of the northern summer his water ice makes for dust and the measurements of the seasonal behavior of water vapor over the planet suggests that there is a vast reservoir of ice beneath the surface so that one can think of the residual polar cap as the tip of an iceberg protruding from a sea of rock at lower latitudes the water vapor condenses to form clouds that ride high in the atmosphere or swirl around the slopes of Martian volcanoes and further south in the canyons and valleys there is frequently a nice haze seemed to form and evaporate in the early hours of the morning as the Sun warms the atmosphere oh no the oceans heat in moisture and the heat and air currents over land masses interact to produce complex weather patterns on Mars because of the absence of large bodies of water and of massive cloud covers the weather doesn't vary much from day to day like a remote weather station on earth Vikings meteorology instrument measures Mars atmospheric pressure temperature wind speed and wind direction temperatures range from minus 122 degrees Fahrenheit just after dawn to minus 22 degrees in the mid afternoon light winds from the east in the late afternoon changed to light winds from the southwest after midnight maximum wind speed is 15 miles per hour but in the early summer the heating of dust particles in the air generates violent dust storms and the whole regions of the planet driven by winds that reach 150 miles an hour they may blanket the entire planet in a few days in order to understand the geology and physics of windblown particles on Mars we're conducting a series of experiments using this this enormous face environment chamber here at NASA's Ames Research Center we've placed an open-circuit wind tunnel in this chamber and we're able to operate at atmospheric surface pressures comparable to those on Mars in this particular series of experiments we have placed a crater model in the tunnel floor and we want to determine the zones of erosion and deposition around the crater in this particular case we're going to let the wind blow across the crater and see what those zones of erosion and deposition are like the light and dark streets associated with craters are the most common features on the surface of Mars related to wind the light streets are deposits of fallout from the global dust storms the dark streaks our regions from which a thin layer of light material has been removed revealing a darker underlying surface these streets serve as wind markers their patterns define the wind flow to the geologist the features seen in the tens of thousands of photographs transmitted by Viking or the visible signs of the enormous forces and processes that have shaped the surface of Mars the excavation of large basins and craters by the impact of meteorites and asteroids the raising of mountains by the action of volcanoes the faulting and subsidence of the crust as the planet expanded and the cutting of channels by water or abrasive particles driven by winds over a period of tens of millions of years the key to the agent sequence of these features is found in the number and condition of craters those areas with fewer skaters are assumed to be the youngest here a fresh crater Oba lies an ancient eroded one here the rim of a crater is eroded by water or wind and here adjacent to a fresh crater is one of the cluster of Crater rings craters that have been buried to varying depths over millions of years the repeated flows of lava built the volcanic mountains of Mars twelve are larger than any on earth the largest Olympus Mons rises three times higher than Mount Everest and is broad enough to cover the whole chain of volcanoes that form the Hawaiian Islands the great gash that cuts through Mars equatorial zone is Valles Marineris a mighty canyon system that extends over an area more than 3,000 miles long and up to four hundred miles wide and drops four miles below the flat cratered surface of the plateau canyon walls are gullied dissected by tributary canyons or scarred by catastrophic landslides leaving steep cliffs and great fractured surfaces extending for 30 miles on the canyon floor is a field of sand dunes suggesting that some of the debris produced by the collapse of the canyon walls was removed by wind these ancient channels that resemble dry riverbeds on earth could have informed by primeval rainstorms but the vast channel system that starred in areas of collapsed terrain with broad stream lines extending hundreds of miles across the lowlands and teardrop-shaped Ireland soaring to thousands of feet above the channel bed testified to a process without any parallel honor viking also photographed the two cratered moons of Mars Phobos the inner moon marked by striations which on closer view resolved into grooves several miles long and Deimos a smaller outer lone Viking traveling at 3,800 miles an hour and passing only 30 miles away could observe boulders on the moon's surface some as large as 100 feet across the geologic record of the planet suggest that Mars like the earth has experience periodic changes of climate the best evidence of this is seen in the strange spiral patterns of Mars polar regions the dark bands are scarps or cliffs of bare ground within the north polar ice cap on each scarp are numerous small terraces eroded from layered rocks this is a model of layered terrain an area about 40 miles across it is believed that the large scarps and the small terraces represent two different cycles of climatic change which occur simultaneously because of Mars oscillation in its orbit about the Sun the polar regions are alternately warm and cold or periods of tens of thousands to millions of years during the cold period mixtures of dust and ice were deposited in a series of near horizontal layers obscuring the underlying topography then a period of warmer climate followed and erosion said Eden cutting deep valleys into the icy mass of the polar caps after the erosion cycle new layers were laid down and another episode of erosion followed this oblique truncating of one set of terraces by another indicates that the climate turns on and off the first jeweler evidence for cyclically marek change on a planet other than the earth the speculations about changes in the atmosphere and climate were closely related to the notion that life in some form might exist on Mars on earth life developed several billion years ago at a time when the overall properties of Mars and the earth were very similar Mars and the earth involved separately however Mars today still has chemicals on its surface and atmosphere temperatures and pressures within which we believe life can exist the Viking Lander was equipped with three life detection experiments designed to test for chemical changes caused by life processes that are familiar to us on earth on earth all living organisms interact with the environment through a process called metabolism animals for example take oxygen from the environment and use it to combust food thereby obtaining energy at the same time they release carbon dioxide and other waste products into the environment green plants and some microorganisms do the reverse in the process of photosynthesis they remove carbon dioxide from the environment and using sunlight as the energy source they convert the carbon dioxide into organic matter and release oxygen into the environment if the experiments on Mars indicated that similar processes were occurring then we would presume the possible existence of organisms on that planet well our results are NARS in certain experiments gave us data that seemed to mimics the metabolism of living organisms however careful analysis of that data indicates that it is probably the result of chemical rather than biological processes on earth all biological systems are based on organic chemistry and it was believed that life on Mars would also be based on organic compounds the notion was strengthened when experiments on earth demonstrated that organic materials can be formed under simulated Martian conditions we use finely powdered minerals like those expected on the Martian surface then we added traces of water vapor and radioactive carbon monoxide at low pressure to simulate margin sunlights who use irradiated the mixture with light from a xenon arc lamp when we heated the sample and captured the gases that were formed or radiation counters showed that the carbon monoxide and water had been converted to organic compounds but vikings instruments failed to detect organic compounds of any kind that fact in the opinion of some observers has increased the odds against the existence of living organisms on Mars if we were able to do a thousand experiments different experiments on Mars and to do these in a wide variety of places on Mars in the canyons on the polar caps in some deep areas of the surface and if in all of these experiments we've got negative results then the answer to the question is there life on Mars would almost certainly be no but on the basis of just a few experiments done at only two sites very bland sites on the planet I think that would be unscientific for us to come to that conclusion all we can really say for sure is that we have run across some very interesting chemistry a kind of chemistry that we do not see in surface samples from the earth or surface samples from the moon and that's about where we are at the moment today in laboratories across the nation scientists are trying to simulate the results that we obtained on Mars some of the scientists are concentrating on irradiation experiments to see whether solar energy acting on Mars could have produced chemicals to account for the results other experiments are assuming that these chemicals were there and are testing one or another of these chemicals to see whether they can account for the results that were obtained the question of life on Mars is only one of the inexhaustible number of questions for which we continue to seek answers and space questions about the origin and evolution of the solar system of our own planet and our own species the search for answers is a goal of planetary exploration and the journeys of our spacecraft to the near and far reaches of the solar system are beginning to provide some of the answers

Channel: US National Archives

Views: 61,868

Rating: 4.6840334 out of 5

Keywords: US National Archives, NARA

Id: dZzY8-nxabA

Length: 28min 32sec (1712 seconds)

Published: Tue Dec 15 2015

Reddit Comments

[u/Oddnumbersthatendin0]

It's crazy how much we've learned, and also how our technology that we use to explore Mars has advanced. back then, two stationary landers was revolutionary, but today we have one rover still operating, another on the way, multiple orbiters, and Insight.