Life on Mars: the Search
by SpaceHike.comMore articles in SETI
In 1898, when H. G. Wells published War of the Worlds, humans became frightened with anticipation of life on the planet Mars. The astronomer, William Herschel had observed several dark areas on the Mars surface during the latter part of the 18th century. Herschel speculated that these dark spots were seas of water. Once the mention of water entered the picture, the probability of life on Mars became plausible. Giovanni Schiaparelli made detailed studies of Mars, in which he made mention of seeing channels. Many interpreted this to mean that canals had been built by intelligent life forms. In July 1965, Mariner 4 probe sent back pictures of a barren surface on the Red Planet, or Mars.
Water is important to scientists when seeking life on other worlds. Life on Earth needs water to survive. Evidence so far suggests that water may have once flowed on Mars, but with the planet's frozen conditions of today, life as we know it cannot exist. Probes visiting the planet have observed channels that could only have been formed by running water. The chaotic region of Mars (large block-strewn area) may have been formed when water was locked in the ground and then began to make a rapid escape that cause the surface to break.
The Mariner 9 probe sent back information showing the Valles Marineris canyons and large volcanic forms on Mars from 1971 to 1972. The two Viking spacecraft arrived on Mars in 1976. Each one had a lander, which was released by a parachute, carrying a payload of advanced experiments hoping to find signs of living organisms on the planets surface. One of the experiments was to search for gases that are produced by living organisms within the soil of Mars. Hope was high at first, but later studies concluded non-biological explanations for the first results. The Surveyor probes are sending data that is being used to piece together the climate history of the planet.
One of the more helpful signs for life on Mars came from an ancient Martian meteorite. It's name is ALH84001, and it is believed to have hit in the Antarctic around 13,000 years ago. The make-up of the meteorite contained evidence of life from organic chemicals. It is believed that these minute structures could possibly have been made by living organisms.
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