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Mars: Is There Life on Mars?       The totality of life is merely a fancy kind of       rust, afflicting the surfaces of certain       lukewarm, minor planets            -- H.J. Muller      Martians have fascinated everyone from the greenest layman to astronomers as reputable as Percival Lowell. He was a staunch advocate of their existence, which he thought could be proved by scientific observation. Viewing the red planet, Lowell observed what seemed to be artificially straight canals, which he took as proof of Martian civilization. It would have been a shock for him to know that humans, not Martians, had created the canals. Human brains instinctively make sense of small, unrelated lines at a distance by combining them into longer, straighter lines.      Another proof cited by Lowell and others were the shifting colors of the planetary surface—proof of agriculture. Alas, this too is a mind-forged illusion, due to the union of incident angles and observational positions.      These explanations were not known at the time, however, and until the Mars Global Surveyor 96 conclusively demonstrated that there was no Martian civilization, excitement warred with skepticism in the popular mind. Consider the 1938 Orson Welles radio broadcast adaptation of H.G. Wells’s War of the Worlds. To heighten the effect, Welles had the play written so that it sounded like a news broadcast. Music was interrupted a number of times by false bulletins reporting a flaming UFO dropping on New Jersey. Soon other actors playing reporters and announcers described the landing of the Martian expeditionary force. People went wild. They crowded highways, hid in basements, even wrapped damp towels over their heads to ward off poison gas.      Now there is new talk of life, though not an advanced civilization. At the laboratories of the Johnson Space Center and of Stanford University, a NASA research team has found evidence “strongly suggesting” that primitive life existed on Mars more than 3.6 billion years ago. The evidence came in on ALH84001, one of the twelve Martian meteorites found on Earth. Roughly 13,000 years ago this 1.9 kilogram potato-shaped rock fell to Antarctica from Mars, where it had existed for more than 4.5 billion years, about the time Mars was formed. In 1984 a team of the National Science Foundation’s Antarctic Meteorite Program discovered it.      It took many years before the NASA research team could analyze the rock, which it did over two years. They published their results in the August issue of the journal Science. The evidence the article presents is wide in scope, but indirect. There are organic molecules (molecules containing carbon, the first thought to be of Martian origin), possible microscopic bacteria fossils, and rock features such as miniature tubes, all of which suggest primitive life. The results indicate that microscopic organisms were fossilized in carbonate minerals deposited in the rock’s fractures. These organisms, which resemble primitive strands of Earth’s bacteria, are small: the largest is less than 1/100 the diameter of a human hair, the smallest is a tenth of that size.      The team invited the worldwide scientific community to scrutinize their results, which it is currently doing. Some scientists have moved to instantly discredit the findings, claiming that the rock either doesn’t contain a fossilized record, or that the rock was contaminated by Earth’s bacteria. Other scientists whole-heartedly support the results of the NASA research team. Carl Sagan proclaimed it a possible turning point in human history. The majority of scientists, however, are undecided. Perhaps more evidence will be gathered by the next Mars mission, the first one to contain a lander with a powerful geological analysis kit. Copyright © 2000 by Gary Chan and Matthew McDermott. All rights reserved.