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Above the horizon, the Martian sky looked surprisingly bright*—evidence, say some scientists, that the atmosphere is richer than expected in light-diffusing particles. In the sky was a shadow— perhaps a cloud composed of water vapor.
The illusion of standing on the Martian plain became even more vivid when scientists produced a color picture that confirmed the appropriateness of Mars' longtime sobriquet of Red Planet. The soil seemed to consist of a fine-grained reddish material interspersed with small blue-black or blue-green patches. Many of the rocks were also coated with a reddish stain, strongly suggesting the presence of iron that had rusted in the presence of atmospheric or waterbound oxygen. Other rocks, blue-green and opalescent, reminded some scientists of copper ore. After correcting the color values on the photograph, scientists decided that the sky, which looked blue in the original print, was really of a pinkish hue. All in all, the view, far from being alien and forbidding, seemed almost inviting. "Oh, gosh, that's just lovely," said Thomas Mutch, head of the team charged with interpreting Viking's photography. "You just wish you could be standing there, walking across that terrain."
The rhapsodic mood in the mission-control room at J.P.L. was in sharp contrast to the tense atmosphere earlier that morning when the Viking 1 lander responded to a command by separating from the orbiter and beginning its 3-hr. 17-min. descent to the surface. Penetrating the Martian atmosphere, it shed its clamshell-like protective covering, deployed a 53-ft.-diameter parachute to slow its descent, and shortly before touchdown fired its retrorockets to brake its fall further. Engineers at J.P.L. watched nervously as the signals on their consoles marked the completion of each stage of the landing procedure. Because the signals, traveling at the speed of light, took nearly 19 min. to travel from Viking back to earth, scientists at J.P.L. were only too well aware that while they waited, the lander had already met disaster— or made history— on Mars.
No Monsters. Once the first lander was safely down on Martian soil—thereby assuring at least partial success of the $1 billion, eight-year-long Viking project—scientists decided that they could afford to be less cautious with Viking 2, which is approaching Mars and scheduled to go into orbit on Aug. 7. Last week scientists were considering setting the second lander down in a rugged northern region that would be more hazardous for landing than Viking 1's site but potentially more interesting to geologists and biologists.