A Closeup Look at Mars
After centuries of questions about the possibility of life on Mars, one of two spacecraft designed to provide some answers on that subject landed on the surface or the Red Planet in August, 1976. Viking Lander 1 settled to the surface of the western slope of Chryse Planitia. Viking Lander 2 touched down on Utopia Planitia about six weeks later, on September 3, 1976.
The Viking project was the culmination of the first phase of the United States’s Mars exploration effort. During the 1960s and early 70s three Mariner spacecraft snapped photographs as they zipped past Mars; a fourth mapped the planet’s surface in detail during a year in orbit.
Viking, however, greatly expanded on the accomplishments of the Mariner probes. The Viking project consisted of the flotilla of ships – two landers and two orbiters. While the orbiters photographed the entire planet, the landers measured weather conditions, listened for Marsquakes, and obtained the first photographs from the Martian surface.
One of the primary Viking objectives was to search for life. Each lander carried biology experiments to scan the soil for microscopic life and search for evidence of metabolic processes similar of those of earthly organisms. The experiments did, in fact, produce results that could be interpreted as signs of life. But scientists later determined that the findings were caused by unusual properties of the Martian soil, not biological processes.
Nevertheless, Viking was a rousing success. The orbiters beamed more than 51,000 photographs to Earth and the landers added 4,500 more. All four spacecraft performed long past their planned operating lifetimes, with Viking Lander 1 continuing to transmit vital data until November 1982.
Planet Mars as seen through a good telescope