In August 1996, NASA issued a press release that suggested evidence had been found to indicate life on Mars. Meteorite ALH84001, it was discovered, showed several mineral features “characteristic of biological activity” and, more importantly some possible, microscopic fossils of primitive micro-organisms. These ultra-thin, worm-like ‘fossils’ appeared to be segmented, but it was about one five thousandth of the size normally associated with such bacteria.
Skeptics were quick to jump on the claims. As no known life forms on this planet were of the size of that found in the meteorite, they said, it was therefore very unlikely that the findings were an indication of ‘life’, fossilised or otherwise. It was also ironic that the staggering claims came at a time when funding for Mars projects was being sought, against a background of an American public which was looking increasingly unsure of whether their taxes were being wisely spent in space.
Today, they jury remains out on the issue. Interestingly, in 1999 organisms only 20 nanometers across were discovered in rock samples taken from several miles under the seabed off Western Australia. These were found to grow when subjected to more normal conditions and given some food. Despite this being a boost to Mars-life theorists, the fact remains that issues such as ‘Life on Mars’ are, today, far more about speculation than concrete evidence. It could be argued that the existence of life somewhere in the Universe other than our own Mother Earth is an inevitable truth, purely by extrapolating the theory of evolution to other planets. If, eventually, solid evidence is found, it is likely that we are in for another shake-up of our science, religious beliefs and maybe even our social structures. Darwin and Marx would be proud.