How accurate are the Martian MER instruments for detecting minerals

[rlb2]

With the external calibration on the MER rovers not working right how can they have a chance of finding carbonates even if they were without the addition of a Raman type spectrograph??? <br /><br />What are there mind-sets here for trying to explain whether carbonates exist on the surface of Mars in a sufficient amounts without the proper instruments to detect it. Its hard enough in a lab without proper calibration coupons to detect certain carbonates.<br /><br />A lot of us have been waiting for a higher amount of the signatures of carbonates on the surface of Mars from the twin MER's to help support the existence of life past or present on Mars, do we have to wait for the next generation of Martian rovers??? <div class="Discussion_UserSignature"> Ron Bennett </div>

 

[JonClarke]

There was discussion of this I think some time ago. It's too early on a Sunday morning to chase all this up, but as I recall there are two standards for each rover, internal and external. One one of the rovers one of them, I think the external one, did not deploy properly. They main prupose of this was to provide an atmospheric and surface dust calibration (and this information on their IR properties as well). Without it the precision of mineral ID is degraded slightly, but still usable. If something does wrong with the internal standard it should be possible to get a rough calibration against major common minerals present on the surface.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[rlb2]

Thanks for your input. I think we discussed this before, however now that I have my brother in law, PHD at Princeton in chemistry and owns a company that verifies spetro sample readings trapped at my place for the next week in Arizona, I'm going to tap him for information until I drain him of knowledge in his field or he leaves.<br /><br />His name is John; he said as a graduate student he tested Martian meteorite samples in a lab. The instrument he used, Raman Spectrograph, which he said was calibrated with different known carbonate samples still had a hard time distinguishing between carbonates of the Martian sample. He did say that Water would be easier to identify using an internal sample and a known external sample such as inferred. <br /><br />Min-TES and Mossbauer readings because of the weight restriction may not be able to discern certain minerals, John did say the Mossbauer instrument was very good at distinguishing the differences of iron bearing minerals.<br /><br />I dont want to draw any conclusions from this yet. I haven't been following this close enough recently but it seems that at every previous news conference the science teem had very little to say about the abundance, or lack of, carbonates on Mars - is this because there not sure the instruments can detect them accurately under the conditions that they are in???<br /> <div class="Discussion_UserSignature"> Ron Bennett </div>

 

[spacechump]

<i>I dont want to draw any conclusions from this yet. I haven't been following this close enough recently but it seems that at every previous news conference the science teem had very little to say about the abundance, or lack of, carbonates on Mars - is this because there not sure the instruments can detect them accurately under the conditions that they are in???</i><br /><br />It looks as if they had found traces of them already:<br /><br />http://marsrovers.jpl.nasa.gov/newsroom/pressreleases/20040109a.html<br />

 

[JonClarke]

I've never worked with either Mossbauer or laser Raman, but i have used the PIMA near IR spectrometer for mineral identification. That uses an internal standard (gold) for calibration. Your BiL is correct, that Mossbauer only works for iron-bearing minerals, and is guite difficulty to interpret.<br /><br />As I recall, the detection limits for mini-TES are a few percent. <br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>