QUOTE (TheChemist @ Jul 12 2008, 03:14 PM) 
Why utter the magic words (open sesame) any sooner than needed, say one day before delivery ?
You mean we're not one day from delivery yet?!
Full Version: TEGA (Thermal Evolved Gas Analyzer)
You mean we're not one day from delivery yet?!
Unjustified rant, and replies to it - deleted. If people wish to debate the rules or the application of them, send me a private message. This thread is not the place.
The news item on the Phoenix site today reports on the test using the rasp to collect ice shavings:
What might TEGA reveal about the ice sample--that the putative ice is in fact real ice, or something more?
EDIT: Also, is there a synopsis of what the results were of the first sample baked? E.g., did they get a C13/C12 ratio? Anything of note?
QUOTE
"This was a trial that went really well," said Richard Morris, a Phoenix science team member from NASA's Johnson Space Center, Houston. "While the putative ice sublimed out of the shavings over several hours, this shows us there will be a good chance ice will remain in a sample for delivery" to Phoenix's laboratory ovens.
What might TEGA reveal about the ice sample--that the putative ice is in fact real ice, or something more?
EDIT: Also, is there a synopsis of what the results were of the first sample baked? E.g., did they get a C13/C12 ratio? Anything of note?
QUOTE (jmknapp @ Jul 17 2008, 02:44 AM)
What might TEGA reveal about the ice sample--that the putative ice is in fact real ice, or something more?
Whether or not it's real ice should be the very least of what it can tell. When an icy sample heats up, H2O would be by far the majority species released. Also D:H ratios, which are hugely interesting -- they may match the atmospheric D:H perfectly, or be significantly different, which would tell us whether there is significant interchange over long spans of time. Those two measurements should be guaranteed.
What else it might find is up to Mars. Salts, etc., will not become gaseous when heated, but anything else that does will be of interest.
QUOTE (JRehling @ Jul 18 2008, 05:21 PM)
Also D:H ratios, which are hugely interesting -- they may match the atmospheric D:H perfectly, or be significantly different, which would tell us whether there is significant interchange over long spans of time.
In the last press conference (just a distant memory now) they reported having successfully baked the first sample:
QUOTE
Scientists on Thursday also discussed the preliminary results of another experiment, in which a soil sample was baked to 1,800 degrees Fahrenheit. The sample contained carbon dioxide gas as well as water vapor, said William Boynton, a lead scientist on the Thermal and Evolved Gas Analyzer, or TEGA.
So should they not have a D:H and C13:C12 measurement already?
QUOTE
What else it might find is up to Mars. Salts, etc., will not become gaseous when heated, but anything else that does will be of interest.
According to Wright and Pillinger, Mars, Modulus and MAGIC:
QUOTE
Apart from H2O and CO2 other trapped volatiles could be studied [with evolved gas analysis], e.g. simple organic molecules (hydrocarbons, for instance), and clathrates containing CO, CH4, NH3, etc. These entities may not always be simply trapped atmospheric constituents; rather they may have been synthesized within the regolith. This could be the result of fluid interactions with other minerals, the input of extramartian materials, free-radical chemistry, or possibly by biological reactions.
In a TEGA test run on shale:
QUOTE
As would be expected, there are significant differences in the evolved gas behaviors for samples run under combustion and pyrolysis conditions (Figs. 1 & 2). In combustion experiments, organic C in the form of CO2 and H2 evolved between 300-600ºC (Fig. 1); whereas, CO2 and H2 evolved between 450-600ºC in pyrolysis experiments (Fig. 2). CO2 that evolved between 650-750ºC is primarily due to the thermal decomposition of dolomite, although, some of the CO2 evolved in this range for the pyrolysis experiment may be due to decomposition of the kerogen (see below). Nearly all of the kerogen was “cracked” into CO2, H2, and H2O in the combustion experiments with the exception of a mass 41 fragment that we have assigned to C3H5 and mass 15 that we assigned to methane.
So even with the ice subliming away before they had a chance to bake this first sample, ought there not be some significant results from the analysis regarding other substances (including adsorbed water that came off at high temperature)? I believe the analysis equipment was reported as working to specs.
Wow Jim! Thank you so very much for posting that link to the article on the TEGA analysis of the Green River Shale (TEGA [Thermal Evolved Gas Analyzer] thread, post 405)
Ming et al. LPS 37 (2006) Abstract 1780. "Thermal and Evolved Gas Analysis of Geological Samples Containing Organic Materials: Implications for the 2007 Mars Phoenix Scout Mission."
(In a lucky coincidence, I will be making a presentation on the North Carolina Fossil Club trip to the Green River Formation in Wyoming [and Dinosaur National Monument] tomorrow. This abstract will help extend it out to Mars!)
The Green River Formation Shales tested in the abstract are not "typical" shales. They are very light colored and contain large amounts of organics. When broken or scratched, they release a faint odor like asphalt. They are currently being examined for hydrocarbon extraction (estimated reserves in Utah/Wyoming/Colorado similar to Saudi Arabia), but it is very expensive to extract. This formation is of Eocene age [50-30 MYA] and formed in great freshwater lakes surrounded by lush tropical forests and swamps. They are most famous for the beautifully preserved freshwater fish fossils (it is illegal to collect vertebrate fossils on public land, but there are pay quarries available near Kemmerer, WY), but well-preserved invertebrate fossils can be found throughout the formation. [Including an insect-rich area we found in NE Utah].
Below is an image of a Herring fish (Diplomystus dentata) split out by myself at Ulrich's Splitting Quarry, Lincoln Co., WY. This fossil is about 6 cm long. The substrate rock is Green River Formation shale.
Click to view attachment
[I highly recommend a visit to Fossil Butte National Monument, WY. For it's size, the Visitor Center/Museum is possibly the best museum I have ever visited.]
The shale analysis tested in the abstract was most-likely highly organic-rich.
-Mike
Ming et al. LPS 37 (2006) Abstract 1780. "Thermal and Evolved Gas Analysis of Geological Samples Containing Organic Materials: Implications for the 2007 Mars Phoenix Scout Mission."
(In a lucky coincidence, I will be making a presentation on the North Carolina Fossil Club trip to the Green River Formation in Wyoming [and Dinosaur National Monument] tomorrow. This abstract will help extend it out to Mars!)
The Green River Formation Shales tested in the abstract are not "typical" shales. They are very light colored and contain large amounts of organics. When broken or scratched, they release a faint odor like asphalt. They are currently being examined for hydrocarbon extraction (estimated reserves in Utah/Wyoming/Colorado similar to Saudi Arabia), but it is very expensive to extract. This formation is of Eocene age [50-30 MYA] and formed in great freshwater lakes surrounded by lush tropical forests and swamps. They are most famous for the beautifully preserved freshwater fish fossils (it is illegal to collect vertebrate fossils on public land, but there are pay quarries available near Kemmerer, WY), but well-preserved invertebrate fossils can be found throughout the formation. [Including an insect-rich area we found in NE Utah].
Below is an image of a Herring fish (Diplomystus dentata) split out by myself at Ulrich's Splitting Quarry, Lincoln Co., WY. This fossil is about 6 cm long. The substrate rock is Green River Formation shale.
Click to view attachment
[I highly recommend a visit to Fossil Butte National Monument, WY. For it's size, the Visitor Center/Museum is possibly the best museum I have ever visited.]
The shale analysis tested in the abstract was most-likely highly organic-rich.
-Mike
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