A Martian Microbe?

Kingdom: Unknown
Scientific Name: Unknown
Image Courtesy of: N.A.S.A
Image Width: 450 nanometers
Image Technology: SEM (Scanning Electron Microscope)

In August of 1996 NASA scientists reported finding what look like fossils of microbes inside a meteorite (called ALH84001) thought to be from Mars. They believe the 4.5 billion year old rock was once a part of Mars. It was blasted from Mars by a huge meteor impact 16 million years ago. It fell to Earth in Antarctica 13 thousand years ago. A piece of the meteorite was discovered on an ice field in Antarctica by scientists in 1984. Inside of the meteorite, along cracks and fissures within the rock, scientists found mineral structures such as the one shown here. Some scientists believe this may be a fossil of an ancient Martian microbe, similar to Earthly bacteria. Other scientists are skeptical, and believe that these deposits are the result of inorganic chemical processes that by chance happen to resemble terrestrial monerans. The NASA scientists have also found traces of chemicals within the cracks in the meteorite that they believe came from living organisms. These polycyclic aromatic hydrocarbons (PAHs) and carbonate globules may be products of microbial metabolisms. Visually, this structure certainly does resemble rod-shaped bacteria found on Earth. It is, however, quite small compared to terrestrial monerans; it's size is closer to that of large viruses than to the size of most bacteria. Most scientists doubt that life currently exists on Mars. However, it is very likely that Mars was much wetter early in the history of that planet, and water seems to be a critical ingredient for the formation and continuation of living organisms on Earth. Further studies, including two NASA space missions due to be launched toward Mars in late 1996, may shed additional light on the question of whether there is life elsewhere in the universe.