Thursday, November 26, 2009
Martian Meteorite May Show Signs Of Life.
November 25th, 2009
New Findings On Alan Hills Meteorite Point to Microbial Life
Written by Nancy Atkinson
Scientists caused quite a stir in 1996 when they announced a meteorite had been found in Antarctica that might contain evidence for microscopic fossils of Martian bacteria. While subsequent studies of the now famous Alan Hills Meteorite shot down theories that the Mars rock held fossilized alien life, both sides debated the issue and the meteorite is still being studied. Now, Craig Covault in Spaceflightnow.com reports that a new look at ALH84001 provides "evidence that supports the existence of life on the surface of Mars, or in subsurface water pools, early in the planet's history." Covault says we can expect a public announcement by NASA Headquarters within a few days.
Research using a more advanced High Resolution Electron Microscopy than was in existence when the initial findings were made 13 years ago has provided the new evidence. Covault reported that the "laboratory sensors are being focused directly on carbonate discs and associated tiny magnetite crystals present inside the meteorite Allen Hills ALH 84001." The data reveal information that counters a "wide range of opposing theories as to why the finding should not be supported as biological in origin."
The new findings were reported in the November issue of the respected journal Geochimica et Cosmochimica Acta, the journal of the Geochemical and Meteoritic Society. The authors include Kathie Thomas-Keprta, Simon Clement, David McKay (who led the original team), Everett Gibson and Susan Wentworth, all of the Johnson Space Center.
Covault said the new work centers on what is called magnetic bacteria that on Earth, and Mars as well, leave distinctively-shaped remnants in the rock. These features test with a high chemical purity more like a biological feature than geological.
Scientists say micro-fossils of bacteria are nested with tiny crystal magnetites that provide additional evidence for life. Credit: NASA