Feb 2 1972
From The Space Library
Mariner 9 news conference was held at NASA Hq. Spacecraft (launched May 31, 1971) was in 81st day in Mars orbit, had accepted 25 000 commands, and had taken about 5000 pictures. Dr. Bradford Smith of New Mexico State Univ. said wind- transported dust that had obscured early Mariner 9 photography was more widespread and occurred more frequently than generally had been supposed; substantial quantities of surface dust were displaced each Martian year by local winds that varied with season and with specific areagraphic location; and large-scale atmospheric instabilities occurred, producing hemispheric and global dust storms which were seasonal but apparently did not occur every Martian year. Storm observed by Mariner 9 had begun in late September 1971, reached its peak in late October, and had cleared slowly until mid-December. Planet was quite clear in February. Mariner.9 photos included pictures of huge volcano with base 500 km (300 mi) wide, Harold Masursky of U.S. Geological Survey told press. ". . . as the storm cleared we were able to establish that the dark spots that we saw barely sticking up through at first" were "the very summit of Nix Olympica. This tall mountain with a complex crater at the top and the scalloped edges and the flat, or non-raised rims indicated to us that this was probably a multiple volcanic vent. As the storm continued clearing finally we could see all the way down to the great plains at the base of the mountain. Now this is a great volcanic pile . , twice as big as the great volcanic pile that forms the Hawaiian Islands. The Hawaiian pile is about 225 kilometers [140 miles] across and ... about 9 kilometers [6 miles] high. It is the largest volcanic pile on the earth. It is something like 32,000 feet [9800 meters] from the floor of the Pacific to the top of the mountain." Photos also showed "spectacular channel" 100 km (60 mi) long with numerous side branching valleys that ended in featureless areas. Absence of vents at ends of valleys made gaseous eruption formation improbable and suggested channel might have been formed by water erosion. Highest amount of water vapor-one thousandth of that in earth's atmosphere-above Mars' south polar cap suggested that water vapor was being released from region as cap retreated. Absence of vapor over north polar cap indicated that water vapor there was condensed in carbon dioxide and was transported by storm or by general circulation from south polar cap to north polar cap. Vapor over south polar regions was slightly less than 20 precipitable micrometers. Mariner 9 photos of Mars had provided data which conflicted with data from 1969 Mariner 7 Mars probe. From 1969 photos of heavily cratered planet experimenters had decided that Mars was "a dead planet, very primordial . . . the product of the accumulation of the cosmic debris that fell in to form the 'planet."
Mariner 9 photos showed "something very, very different indeed.... we can see the great volcanic piles and because of the crispness of the edges and the lack of craters, we think these are geologically young . [and] we have a geochemically evolved planet." Comparison of 1969 and 1971 photos showed that south polar cap regions completely covered by frost in 1969 were only partially covered in 1971. During period when photo-graphed by Mariner 9 little separations had widened and solid carbon dioxide coverage had broken up until many dark spots showed through as the ice sublimated and revealed underlying dark rocks. Dr. Charles A. Barth of Univ. of Colorado reported that Mars atmosphere was primarily carbon dioxide but also contained atomic hydrogen and atomic oxygen. "The atomic oxygen comes presumably from the photo-dissociation of carbon dioxide and the atomic hydrogen comes most probably from the photo-dissociation of water vapor." Amount of atomic hydrogen varied very little with altitude. Atomic hydrogen extended some 20 000 km (12 000 mi) from planet like a "great big sphere of glowing hydrogen atoms with the spacecraft running around through it. Those hydrogen atoms are put there from photo-dissociating water vapor and because of the very low gravitational field of Mars, it is relatively easy for these atoms to escape. In fact, the picture that we have, is that water comes up out of the surface of Mars, goes into the lower atmosphere ... [and] gets deposited in the polar caps; when the polar caps thaw, it is released into the atmosphere." Atomic hydrogen was escaping into upper atmosphere at rate equal to 380 cu m (100 000 gallons) of water per day. (Transcript)
NASA was working with Dept. of Transportation (DOT) to define characteristics of clear-air turbulence (CAT) better and to develop methods of detecting it in flight, Flight Research Center announced. Instrumented B-57 aircraft-equipped with DOT prototype radiometric sensor able to detect CAT up to 80 km (50 mi) ahead of aircraft- was being flown at altitudes up to 15 000 m (50 000 ft) in areas over western U.S. where CAT was expected. Aircraft also carried Univ. of Wyoming aerosol and ozone detector to determine relationship between presence of aerosols or ozone, or both, and atmospheric conditions that caused CAT. Since tests began one year before, B- 57 had completed 13 flights. February 2: Flight Research Center flew a B-57 aircraft equipped with Department of Transportation prototype radiometric sensor and Univ. of Wyoming aerosol ozone detector in a NASA-DOT program to develop methods of detecting clear-air turbulence. When CAT was encountered, 30-min flight pattern was flown to record data in turbulent area. (FRC Release 1-72)
Kennedy Space Center announced two contract awards. McDonnell Douglas Corp. was awarded $15 945 000, one-year contract modification for prelaunch, launch, and postlaunch operations of Skylab air-lock module, Orbital Workshop, associated ground support equipment, special test devices, and facilities. Modification brought total value of contract to $60 599 698. Boeing Co. Field Operations and Support Div. was awarded $22 904 790, one-year contract extension for base support services at KSC and Cape Kennedy Air Force Station. Extension brought total value of contract to $42 122 790. (KSC Releases 24-72, 25- 72)
NASA launched Nike-Tomahawk sounding rocket from Poker Flat Rocket Range, Fairbanks, Alaska, carrying Rice Univ. auroral fields and particles experiment. Rocket and instrumentation performed satisfactorily. (SR list)
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