Jul 2 1976
From The Space Library
2-12 July: By "unanimous" vote among nearly 30 Viking project scientists, Viking 1 would land 17 July in a site called the "Northwest Territory" on the Plain of Chryse that would be safer than the original choice, said Project Manager James S. Martin, Jr. A mosaic of more than 40 photos released by JPL showed the plains area more hospitable than the Valley of Chryse, which turned out to be a network of dry riverbeds too steep and too rough to risk a landing. The scientists hoped that the new choice of site would feature sediments, deposited by ancient Martian rivers, that might contain fossils or other traces of life. Being at a lower altitude, the site could harbor water in a liquid form; "snow, ice, and even liquid water are possible on the site we picked," said Dr. James C. Fletcher, Administrator of NASA, in announcing the new plan. (W1 Post, 2 July 76, A-2; W Star, 2 July 76, A-8)
A NY Times editorial mentioned "super technology" in the taking and transmitting of Mars photographs that led to selection of an alternative landing site, "an extraordinarily impressive example" of the potential of "robot explorers of the solar system." (NYT, 3 July 76, 20) Argon gas detected by Viking 1 in the Mars atmosphere suggested that Mars had experienced major volcanic periods that might still be in progress. Carbon dioxide, the only gas previously identified in the Mars atmosphere, had obscured the presence of argon, which had a similar molecular weight. As Viking instruments had detected a reduction in atmospheric temperature approaching the south polar cap, colder than had been forecast because of pure carbon dioxide, the explanation was a dilution by another gas that would conform to the low temperatures, identified as argon. Only about 1 % of earth's atmosphere was argon, but Viking had revealed the Mars atmosphere to be as much as 8% argon above the south polar cap. (W Post, 3 July 76, A-2)
The new landing space chosen for Viking 1 in the Chryse region was about 80 km north of an island formed millions of yr ago by flood waters rushing from the canyon areas near the Martian equator. (W Post, 4 July 76, A-4)
New data received from Viking 1 had provided more questions than answers, such as the reason for unexpected readings of Martian temperature and atmospheric moisture. The Mars south pole proved colder than earlier believed, below the condensation point of carbon dioxide, and had as much as 40 to 50 microns of water in the atmosphere, more than expected. The newly selected landing site would contain sufficient moisture to provide ground fog, frost, or even snow. (W Star, 4 July 76, A-12)
The Viking project demonstrated that man had not lost his "primal urge to explore," said a NY Times editorial 4 July, even with little immediate prospect of economic gain or space colonization. People might worry about the expenditures and priorities of such endeavors, said Dr. Bruce C. Murray, Director of JPL, "but very few say the product itself, the discoveries, is unworthy or immoral." On the Bicentennial Day it was proper to remember that the U.S. was a product of the urge to explore. Whatever it learned about Mars, Viking 1 proved that there was robust life on earth. (NYT, 4 July 76, 4-1)
Failure to find life on Mars would mean a cut in funding for the space program, NASA biologist Dr. Harold Klein predicted. Although he estimated odds at 50 to 1 against Viking's finding life on Mars, he noted that the issue would not be settled because the experiments had built-in limitations. Whether or not life was detected on Mars, most scientists believed life existed elsewhere in the universe, the NY Times added. (NYT, 6 July 76, 15)
JPL released the best photographs to date of the "Martian Grand Canyon," a gorge 10 times the size of Ariz.'s Grand Canyon but relatively small by Martian standards. The Capri Chasm was as much as 32 km wide and nearly 2 km deep, compared to Ariz.'s which was no deeper than 1.6 km, no more than 21 km wide, and about 350 km end to end. The length of the larger canyon of the Valles Marineris on Mars had been estimated at more than 3200 km. Rockslides detected in the Viking 1 photographs indicated either massive quakes on Mars, meteor impacts, or effects of winds reaching speeds over 480 kph, JPL scientists said. (W Post, 7 July 76, A-10)
The Viking 1 landing on Mars was put off until at least 20 July after radar observations indicated the alternative landing site was rougher than previous Viking photographs had shown. The spacecraft's orbit would be shifted to permit examination of an area west of the previously selected landing point. (W Post, 8 July 76, A-2)
An altered orbit put Viking 1 over an area called Plateau of the Moon, third to be scouted in the search for a smooth landing site. Radar echoes, which had revealed dunes or boulders on the Plains of Chryse invisible to the Viking cameras, showed the plateau to be "twice as smooth as the plains." (W Post, 7 July 76, A-2)
A JPL spokesman said preliminary pictures of another landing site proposed for Viking 1 showed Martian terrain as rugged as that in 2 spots previously rejected. Viking 1 was scheduled to take more photographs of a region called West-Northwest, beyond the area that controllers last wk said was too rough for a landing. (W Star, 12 July 76, A-6)
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