Saturday, August 1, 2009

This week in space history: Vikings explore, photograph Mars

Viking 2 entered Mars orbit on Aug. 7, 1976, and set about separating fact from fiction surrounding the red planet.

In 1906, "Mars and its Mystery" (Little, Brown and Co.) theorized that a "large, irregular, dark region" contained "bodies of waters, or seas. Š From remote times it has been taken for granted by the best of minds that other worlds besides ours sustain life."

Wernher von Braun, the German scientist who developed the Saturn V that launched Americans to the moon, and Willy Ley discussed long-held theories in "The Exploration of Mars," (The Viking Press/1956). They wrote: "This was the picture of Mars at mid-century: a small planet of which three-quarters is cold desert, with the rest covered with a sort of plant life that our biological knowledge cannot quite encompass."

In the mid-1890s, astronomer Percival Lowell was lecturing on Martian features he called canals, Mark Littman stated in "Planets Beyond" (Wiley Science Editions/1988).

"Lowell's theory begins with the demonstration that the primary requisites for human life exist on the planet water, heat and atmosphere," the New York Times said in Lowell's obituary (published Nov. 14, 1916, reprinted on the Web site "His positive proof of the existence of human life on Mars is the network of lines which mark certain areas of the planet's face, indicating the digging of artificial canals, which would require an intelligence and engineering skill as great or greater than that possessed
by the inhabitants of this earth."

Littman attributed such speculation to a translation error. He wrote that Italian astronomer Giovanni Schiaparelli "first described thin, straight, crisscrossing features on the surface of the red planet" in 1877. "He named them canali, meaning 'channels.' Channels could be natural or artificial features. The English-language press, however, translated canali as 'canals,' implying that they were built by intelligent beings."

Growing scientific knowledge at the turn of the 20th century began to overcome superstition. The planet long known as "the symbol of the god of war," wrote von Braun and Ley, captured the public's factual fascination in February 1901 when Mars' orbit came close to Earth. Lowell described expectation of the event, known as a "close opposition," in "Mars (Houghton Mifflin/1895.) "Once in about every 15 years, a startling visitant makes his appearance upon our midnight skies a great red spot that rises at sunset through the haze above the eastern horizon. Š Startling for its size, the stranger looks the more fateful for being a fiery red. Small wonder that by man folk it is taken for a portent."

Von Braun and Ley documented that "newspapers and magazines" heralded the opposition. "Teachers pointed out the red planet to their pupils; fathers took their sons out into the open or up on the roof of the house late at night to look at it. And almost for the first time in history people looked up to see the red planet without fear."

NASA launched Viking 1 on Aug. 10, 1975, and Viking 2 on Sept. 9. Each had an orbiter to photograph the planet and a lander to "conduct a detailed scientific examination of the planet, including a search for life," said NASA release "Vikings Converge on Mars" (summer 1976). NASA hoped Viking 1's lander would touch down on the United States' bicentennial, July 4, 1976, but it did not land until July 20. Landing sites were chosen "several years" beforehand. In orbit, though, Viking 2 photographed new locations because the Viking 1 site had been found "unsafe," said "Viking: Mars Expedition 1976" (Martin Marietta Corporation/1978).

Viking 2's lander touched down on Sept. 3, the Web site said, upon Utopia Planitia. "Viking: Mars Expedition 1976" described the area as "a large, broad plain Š 4,500 miles on the opposite side of the planet from the Viking 1 Š a low area, judged by scientists to have high concentrations of water vapor." The book said that just "seven minutes after separating from the Viking 2 orbiter, contact with the lander was virtually lost. Š For nearly 24 hours the only indication of a successful landing was the increase in the rate of information from the lander on the low-rate channel which is automatic with touchdown on the surface."

The first pictures showed "soil and scattered rocks," said "Mars: The Viking Discoveries" (NASA/October 1977). "As the cameras looked out to the horizon, they photographed a gently rolling red landscape that could almost have been a desert scene in the American Southwest. The reddish gray soil was dotted with rocks of all sizes."

In early 1977, NASA put Viking 2 into hibernation because winter's daytime temperatures alone were minus-180 to minus-160 degrees Fahrenheit. The lander recorded data, but delayed transmission. On Sept. 13, 1977, the lander photographed frost on Martian rocks.

By October, the Viking 2 orbiter had taken 8,124 photographs, and the Viking 1 orbiter 7,966 photos.

"Mars: The Viking Discoveries" documented how the landers "took on new tasks that had not been planned before the landing. After digging up samples of exposed soil, (each) lander's sampling arm was used to push large rocks aside to collect soil samples of the protected soil beneath them."

On Aug. 7, 1996, 20 years after Viking 2 entered orbit, President Bill Clinton "announced that a meteorite found in Antarctica contains evidence suggesting the existence of ancient life on Mars," wrote Donald Goldsmith in "The Hunt For Life On Mars" (Dutton/1997).

"On Mars, where the environment for life is neither as harsh as the moon's nor as generous as the Earth's we might find, still preserved, the answers to how life came into being. We might even find life itself," said "Mars: The Viking Discoveries."

Von Braun and Ley hoped man, not landers, would explore. In 1956, they declared, "We, the genus homo of earth, will set foot on Mars within a matter of decades."

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