Organics?

I haven't really dug that deelply into the preliminary results from Phoenix, but there is not much out there on the thermal evolved gas analyzer results for organics in the soil - one of the most critical experiments on the entire mission. From the early reports, the results were basically non-detect, but there's a lot of hemming and hawing in the press releases, and silence since last summer. What's the story? Is the silence an indication that the results were like Viking - zilch? What about rumors of data validation problems with the results? Any feedback would be appreciated.

Viking's results were anything but ziltch. They indicated life, by the parameters of the experiment. They were reinterpreted as possibly coming from hypothesized non-life processes.

Considering that Mars is not hermetically sealed from Earth, a complete zero result for life in areas where the soil chemistry and water environment are conducive to life, seem unlikely.

See http://planetary.org/blog/ for a report from the AGS meeting in San Francisco, with some info on Phoenix results.

I was referencing the Viking organics results, which showed no organic compounds in soil at the two landing sites. From what little I have seen, Phoenix results are the same. Life requires organics. The other Viking results are of course endlessly debatable, but biology is a far less supportable conclusion from those results than inorganic oxidation processes.

Phoenix detected a low-temperature emission of CO2 in the TEGA instrument. Possible explanations included "combusted organics." In other words, the lack of detection of organic molecules per se could be plausibly explained by organic oxidation---the organic molecules would tend to be oxidized to CO2 and H2O when heated together with the oxidizing perchlorate. If perchlorate was present in the Viking soil, this could also explain the Viking results.

There's a good article today in Nature that talks about the mission, its politics, and the early results: http://www.nature.com/news/2008/081210/full/456690a.html

It confirms no evidence of widespread organics, but possible, inconclusive "hints" of some organic molecules. There's also some discussion about the quality of the TEGA instrument and its results, and the bureaucratic sensitivity surrounding it. So the life on Mars debate goes on as before.

Nice link PC Phoenix did well enough but it is clear TEGA fell well short of expectations and I am surprised the checks were not carried out on the width of the filters. The MER's and Phoenix if nothing else will pave the way for MSL and to ensure the same mistakes are not repeated. One of the comments on this link makes sense also, if there is not enough budget for post mission analysis then make it more public there are people here and on UMSF who can chip in. I feel frustrated that we are not launching two missions per year and seriously planning a manned mission, no chance of that in the current economic climate and Man's addiction to war.

http://planetary.org/blog/

Interesting report in today's blog about results presented by the Phoenix scientists at the AGS meeting.

Quote:

"In summary, Hecht said, "We landed expecting to find lots of sulfates, and maybe halite. Instead, we found calcite-buffered solutions, like most water on Earth; we found perchlorate-laced soil; and we're still hunting for sulfates." He said that there's a long list of research disciplines affected by this unexpected soil composition; topping the list is astrobiology. As I mentioned in my previous Phoenix post, they now think that the abundant perchlorate in the soil may have oxidized any organics present before they could be detected by TEGA. "This calls into question any thermal method used to detect organics," he said; and he added that we may even need to go back and look at the Viking results again and think about how the presence of perchlorate could have affected them. The high concentration of perchlorate in the Phoenix soil is hard to account for; but Hecht pointed out that it's very soluble, so that if there's any liquid water present in the soil, the perchlorate would quickly go into solution, and then get left behind if the water disappeared either by freezing or evaporating. "

By the way, the perchlorate appears to be in the form of magnesium perchlorate, which is strongly hygroscopic. (Used as a drying agent on Earth.)

By the way, the perchlorate appears to be in the form of magnesium perchlorate, which is strongly hygroscopic. (Used as a drying agent on Earth.)

Appears to be, is ungodly suggestive. If you got the facts bring them. If it is. If it aint it aint.

Bad dust guy.

Fred

Quote (from http://planetary.org/blog/):

"Next up was Bill Boynton, whose talk on the Thermal and Evolved Gas Analyzer I covered on Tuesday. He was followed by Mike Hecht, who spoke about the Wet Chemistry Laboratory (WCL) results, particularly the discovery of perchlorate. He showed some graphs illustrating the relative amounts of different ions detected in the WCL beakers. The most numerous ions in solution were doubly-charged magnesium cations, and the perchlorate anions, which have a single negative charge; there were roughly equal amounts of the two detected in the soil. So it seems that the perchlorate that they detected in the soil was most likely magnesium perchlorate, but that leaves some excess magnesium to account for, Hecht said (since, to balance the charges, there'd be two perchlorate anions bonded to each magnesium cation). In addition to the magnesium, they also positively detected sodium, potassium, and calcium. Measurements that he said were "still murky" were the quantity of soluble sulfate ion, whether there were any gradients in the soil composition from surface to the surface of the ice table a few centimeters below, and the question of how the cations they detected were associated with anions to make chemicals."

Hi Barsoomer & any chemist / biochemist out there.

Thinking aloud! Magnesium perchlorate can absorb its own weight in water. Could the TECP instrument detect the absorbed water? Is the hygroscopic nature of the Magnesium perchlorate affected by temperature? ie. If temperatures increase would the MgClO4 be expected to release absorbed water? Could perchlorates be a mechanism used for conserving water at or near the surface in a form that is little affected by the very low temperatures and pressures? Could wetness in the soil due to hygroscopic water in perchlorates be actually seen in some Oppy or Phoenix images and be actually what they appear to be?

Is it possible that under certain conditions bacteria which utilize perchlorates as metabolic substrates could find adequate water for their survival in hygroscopic water or water released from the hygroscopic bonding?

One thing seems clear and that is there is still a possibility of microbial life existing on or near the surface of Mars.

Barsoomer, Thanks for checking out and posting your summaries on the phoenix preliminary results.

Winston

“So it seems that the perchlorate that they detected in the soil was most likely magnesium perchlorate, but that leaves some excess magnesium to account for, Hecht said (since, to balance the charges, there'd be two perchlorate anions bonded to each magnesium cation).”

2+2=6. I do not see any arcing.

It is like observing liquid water at -22C. I think Hort said it best, “Mars is a damn strange place.”

Fred

http://martianchronicles.wordpress.com/2008/12/16/agu-day-1-phoenix/

More news from AGS about Phoenix.

Perchlorates are extremely soluble in water, and act as a great antifreeze, making brines with low melting points (-70 C). They also are quite reactive, and when heated they give off oxygen and heat.

Now, sounds like a dust guys dream. Hydrophobic and water soluble. Now who wants there cake and eat it too?

Fred

http://www.youtube.com/watch?v=rWSj3znI_-Y

True, Magnesium perchlorate could be a big help to something trying to survive on mars. In fact when I read the list of properties it almost seems too good to be true! If there isn't anything there using it to survive already I'd bet the farm that something could be put there that would.

I think sometime you guys do not read it all, then neither do I.

Hort found the critters.

Is it just chance at-50C? A weatherman would say, "Not a chance brother."

Fred

http://farm3.static.flickr.com/2253/2934528062_ba21a51988_o.gif