A NanoSIMS instrument at California Institute of Technology. Courtesy Laurent Remusat.by David Tenenbaum
Posted on 08/11/2008 1:23:03 AM PDT by SunkenCiv
Using a new instrument that can locate elements on the nanometer scale, NASA scientists are exploring tiny bits of organic matter that could be the oldest traces of terrestrial life. Possible "biosignatures" have been found in rocks dating back 3.3 to 3.5 billion years, long after deformation by heat and pressure would have obliterated any whole-cell fossils these rocks may once have contained.
These biosignatures would be embodied in suggestive concentrations of elements, like carbon and nitrogen, that are associated with life, and in the ratios of specific isotopes...
NanoSIMS is a fine-scale elaboration on SIMS, also called an "ion probe," which spews a beam of cesium ions that releases ions from the sample surface. Individual detectors on a NanoSIMS instrument are tuned to pick up particular ions, including carbon, nitrogen, oxygen and sulfur...
"What NanoSIMS brings us is a new tool in our arsenal of weapons," says Gibson, who has been involved in numerous studies of ancient biosignatures, including the Allan Hills martian meteorite, a 4.5-billion-year-old rock containing 3.9-billion-year-old carbonates that, he thinks, may carry a credible biosignature.
The earliest putative biosignatures are difficult to interpret and often controversial, due to the generally poor level of preservation of organic material in some of Earth's oldest sediments, but studies of younger rocks have confirmed that NanoSIMS can confirm biogenic structures by pinpointing the location of biologically important atoms like carbon and nitrogen.
(Excerpt) Read more at spacedaily.com ...
A NanoSIMS instrument at California Institute of Technology. Courtesy Laurent Remusat.by David Tenenbaum
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Gods |
To all -- please ping me to other topics which are appropriate for the GGG list. |
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Nice to know we've got 3 billion year old chert in Oz, but what I would like to know is, how is the age of the chert established?
The Universe is pregnant and electric!
What I’d like to know is why it’s nice to know if you’ve got 3 billion year old chertz in your backyard?
Are we looking for grafitti like:
“And on the seventh day I created Helen Thomas and found to my amazement I simply could not correct that mistake”
:’D
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