Ok, you got us. It was a NASA conspiracy all along.

I see the point, and I somewhat agree. Nobody's saying anything about a conspiracy, this is just about making accurate statements about the findings. The press was (rightfully) chastised about making assumptions and not rushing the science teams into revealing information before they were ready, but the same lesson can be applied to the teams themselves. If they had any inkling of these perchlorate findings then they should not have said that you could sprinkle it on your breakfast cereal and eat it. They should have said that "so far it appears not toxic," but there are still signatures to identify. Same criticism can be made about the TEGA short circuit. Don't make definitive statements when you are still in the process of analyzing the signals.

So I kinda agree. It's not that they're doing their jobs poorly or are trying to be sneaky and cover things up, I just think that they, on a very few occassions, haven't characterized their findings to the press as accurately as they could. The reason is probably just their own excitement and eagerness to share their findings, and we can't fault them for that!

(Don't be too hard on me... it's just an opinion! )

The pH was an easy thing to judge. Ditto water. They're a 'Here it is' sort of experiment.

The Perchlorates were not - they take time to figure out, experimentation in labs to match the results. Remember - they're still not confirmed - they're just the current hypothesis - and it's a hypothesis they wouldn't have shared with us were it not for the entire CC issue. Sharing the scientific process with an instrument like MECA just isn't the right way of going about things, but their hand has been forced in this instance.

Perchlorates were unexpected, in part because the are rarely found in nature. We use rather complex electrolysis processes to make perchlorates used in rocket fuels - the perchlorate ion is very energetic, releasing four molecules of free oxygen during decomposition. It is hard to fathom a process on Mars that would make this ion in high enough concentrations to be meaningful.

Since perchlorates - if they exist, were entirely unexpected, none of the analytical processes were specifically set up to isolate perchlorates from other ions. Perchlorate ISE's work very well, but there are any number of contaminates that can poison ISEs and lead to false positives or non-detection. For example, any highly alkaline environment must be carefully buffered before exposing the ISE to the solution.

I'm babbling, but the problem is one always faced when we use robots for exploration: When the regoth contains unexpected materials; the robot can't open a cabinet of analytical reagents that would eliminate all of the unusual suspects. Personally I think it is a good thing that the possibility of conflicting data has been made public. It demonstrates that the science is not always exact, and the best answer - the most likely correct - may not be the first one.

Imagine how convenient it would be though to be able to extract ready-made rocket fuel from the soil--return-voyage energy crisis solved!

Update to my previous post [03:34 PM] on perchlorate interference.

Through the help of a kind UMSF member (thanks !), I got to have a look at the J. Geophys. Res., 2008 (in press) paper about the WCL.
There is no mention of a ClO4- interference, so I guess it is not a problem. In fact I could not find any mention of ClO4- at all !

So, in agreement with Emily's previous post in this thread, I was wrong, there is no [ClO4-]-specific ISE in WCL.
The perchlorate must have been picked-up in the nitrate (NO3-) ISE, which also doubles as a perchlorate one.

I'll preface by saying that I'm totally ignorant about how an ISE operates. TheChemist mentioned that the ISE was designed to detect nitrates but instead detected perchlorates. How do we know the detected material is not some other substance, e.g. hypochlorites? I'd like to see some sort of specification for this sensor indicating its reponse to a wide range of different materials and not simply the material that the investigators had hoped to find.

I might add that once again we've been blind sided by focusing the science too much towards exobiology and not towards general science (we should have learned after Viking). We need to have a more fundamental understanding about the Martian surface before we make sweeping assumptions that it's covered with biological residue.

I think jmknapp's point about researchers apparently having varied views on the habitability question in the presence of perchlorates is very important, at least in explaining the origin of the recent MECA "kerfuffle".

He quoted Kenneth Nealson, from here for example:

To add to this opinion, on the Martian Chronicles blog, Briony Horgan writes:


To add to the confustion, the original NASA press release said (See the latest Planetary update for a clarification of this.)

What all this suggests is some uncertainty amongst the scientists about the habitability significance of perchlorates, and this is understandable if, as we've heard, few people were expecting to find perchlorates! I can easily imagine some science team members who were aware of the MECA evidence before it became public, passing information to journalist friends that there was a potential discovery that was important for habitability, because they actually thought perchlorates would be bad news for life. Hence the genesis of the snowball.

I'm sure we can expect to hear more about perchlorates and habitability. A team member (Smith?) at the briefing admitted to having to learn about perchlorates only after the MECA results. The sceptic in me wonders whether there may be bias amonst the science team, against stating that perclorates have a negative impact on habitability.

The truth, I'm sure, is that it will be hard to settle the question for or against habitability.

Is there any indication of how the (highly energetic and possibly unstable) perclorate was created in the abundances we apparently see? Obviously the energy required would have ultimately come from the sun, but what was the pathway? UV photodissociation and recombination, or something else?

Is this perchlorate in chemical equilibrium with the rest of the soil? Or does it need to be constantly produced to maintain the measured abundance, like Earthly O2 (another oxidizing species)?

I cannot help but think of statements by both Carl Sagan and James Lovelock concerning the importance of nonequilibrium chemistry as an indicator of life -- not that I am saying that perchlorates = life, there may well be (and probably are) nonbiological mechanisms for its production. But any time I see grossly nonequilibrium environments, I would have to consider if "life" has a role in its formation and/or maintenance, or if known nonbiological processes can explain the observations.

I am not trying to raise any sort of hysteria here, but think that this is a valid area of inquiry.

@gallen_53

In my previous posts I provided a couple of links to articles discussing ISEs and their sensitivity (i.e the J. Geophys. Res 2003 paper).
Emily also was quite clear about the perchlorate sensitivity of the nitrate ISE.


Please try to read this material first, most of your questions are answered there.
These measurements are complicated, it is not just reading a value from a LED display !
The Phoenix team knows better than anyone else what their instruments are capable of

I find myself agreeing with the jm's here. Whether for good reason or not, there was "news" being omitted from the press conference. Even if the news was developing, the press should not be condemned for inquiring about it and writing about it. It's what the press does. It's fine to try to keep secrets from the press, (good luck) but it's inadvisable hold open press conferences while doing so. So I don't think NASA is blameless, even if they were well-intentioned.

The press can be condemned for being wrong, though. The "White House briefing" stuff was wrong, apparently, and that certainly fanned the flames. Even if Covault was restrained, certainly those who re-reported his story were not. Bad press, bad.

"Maybe perchlorate" isn't news. But with some nonsense from whereever it came saying there was some sort of news, probably negative toward life, getting briefed at the WH - they had to say something. The fact that a) The perchlorate is not a revelation of any sort for or against life and There was no whitehouse briefing.... the ENTIRE issue is about nothing. The only issue remaining is how or why the rumour got to CC in the first place.

What next, a press conference for every time the temperature is -30 during the day?

Doug

Since the sensor was supplied by Thermo according to the press conference, it would appear that this is the manual for the terrestrial version of this ISE:
http://www.thermo.com/eThermo/CMA/PDFs/Art...sFile_18905.pdf

There is a section on interferences starting on page 34.

Doug, I disagree with you in that I think that the identification of perchlorate is significantly more important than observations of temperature. On the other hand, I also disagree with those who say that the team should not have "hid" this from the public. I can understand very well why it wasn't included in Thursday's press conference. Contrast it with the "Hey, we got some water!" story from TEGA and the "lookit the neat laser shooting into the sky" from MET and the "lookit our pretty panorama" from SSI. Those are incredibly simple to explain in a few minutes on a packed press briefing. For the perchlorate story, although it is very interesting to Mars scientists, it is much more difficult to explain (what is perchlorate? How is it different from perchlorate on Earth? What's it bonded to? Is it bad or good for life? What does it imply about habitability?) I am sure there would have been a perchlorate press conference eventually -- but it may well not have come until at least December's AGU meeting, at which I am sure the story will feature prominently, because by then they'll have gotten their ducks more in a row within the team and will be preparing to present their story to an audience of scientists; there will be abstracts and presentations full of background to help teach people about what they are, how they were found, and why they are important. I am very sure there would have been no perchlorate briefing until Peter Smith at least had done a lot of background reading to learn about what perchlorates were and what they might mean.

--Emily

You think so? Really?!?

Imagine the situation Thursday, before the briefing, the CC question that he reported (omitting the answer) and the hubub after that. Imagine yourself the media guru for the team, summing it up. We have a chemical that we may or may not have identified, that may or may not result from contamination, that may or may not have been confirmed when another instrument was used to analyze the soil, that may or may not be shot down in days when another measurement is made, and that may or may not have some bearing on the goals of this mission to understand habitability. Is your reaction really, "hold the front pages!" If so, is your reaction still that, given that the "may or may nots" are never 50-50, that progress has been made and that there is hope of having good answers to the question by waiting?

If that standard were general it would be a mess. "Hey, that looks like a snail track behind that object" (page 1). "Oh wait, it's just a rock that slid when Phoenix landed" (p 14). I think the team has a responsibility to share what they learn with the public and that they know that. I don't think the team has a responsibility to strive to be the next ALH84001 or cold fusion by dumping all current avenues of inquiry on the public at each press conference. The team has regular science discussions, which reporters are firmly barred from. That is so some preliminary and pretty wild stuff can get discussed, because frankly even the wild stuff needs to get discussed. If it got out, it would stifle that discussion, as well as greatly mislead the public about what is being found.

So at this point, I don't see how one concludes that "news" was withheld or blames the project for saying too little. Certainly not for saying too little prior to the CC tempest.

Thank you Mark, you've managed to say what I've been trying to get across.

Deimos--That is the most rational comment added to this thread today. Science is really a really rigorous process and the science team should be allowed to focus on producing first class science. The team has done a great job of providing news of their research. There is no good scientific reason for the team to every last detail.
-Floyd

I liked the press conference and found the questions and answers a cut above normal but perhap it's because I would like these conferences to last much longer, an hour on perchlorates, so it would be nice to have an hour on MECA, TEGA etc etc. Just hungry I guess, still I would be in trouble without UMSF.
Roy F

@stevesliva - I think you have slightly mischaracterized what I was trying to say (for which I will blame only myself... hadn't had my first cup of coffee yet ). My point was not about whether or not they should have talked about this perchlorate finding way back then. I am on their side on this... I don't think they should discuss anything until they're ready to.

Instead, my point was about making broad-brush statements that don't accurately describe that don't accurately represent their findings. I don't think this has anything to do with misleading the press or "hiding" results, my (very small) critique is simply about the language used. At the time of that particular briefing they had all this wonderful information to reveal about the acidity of the soil and some of the constituents that make up the soil that had been positively identified. They also had this signal that indicated perchlorates, but they did not yet know what that signal was telling them. Within the large circle of possibilities of what that signal meant was the chance that it was actual perchlorate. And that is not something I want to grow vegetables in or sprinkle on my cereal.

I guess the way to best sum up what I'm trying to say is that I wish the answers would have been more "cautious." "So far, this is what we've found but we can't make a statement about habitability until we fully understand the readings - a process that we're still engaged with." It would be different if that perchlorate signal only appeared in subsequent samples, but that wasn't the case.

Hopefully my point makes more sense. I just don't want it to be construed as frustration over results being withheld or somehow "hidden." That's just not what I'm trying to say at all.

No argument, you made good points. There were some interestingly sweeping generalizations based on what was reported or even measurable. Saying less is better than more until all the ducks are in a row.

I had to go back and read the transcript of the "asparagus" press conference after hearing various rumors about what was said vs. what the media made up. And I've got to say that the media were beyond fair in that case. I'll join you in avoiding sprinkling perchlorate salts on my breakfast cereal, and will reserve judgment on the habitability question. And I'm encouraged to see the media, in part, reserving that judgment too.

As usual I was wrong. There is a reference to the possibility of encountering perchlorates in page 5 of the above article .
And then, there is this tidbit in page 7 :


Since there was no chlorate ISE in the '01 WCL design, this is clearly a typo (I hope they catch it in the galley proofs !) : the perchlorate ISE was replaced for Phoenix, as was already suggested in the JGR 2003 paper, because it was problematic, and the nitrate ISE could (and it seems did) also catch perchlorates.

Thank you. I looked at page 34 and noticed that ClO3 causes interference. Not being a chemist, I went to Wikipedia and looked up NaClO3 (Sodium chlorate). This quote caught my eye:

"Sodium chlorate is used in some aircraft as a source of supplemental oxygen. Iron powder is mixed with sodium chlorate and ignited by a charge activated by pulling on the emergency mask. The reaction produces more oxygen than is required for combustion."

Again, I know almost nothing about chemisty. What would happen if sodium chlorate and hematite and/or pure iron were mixed together in water?

I think we've whipped that horse long enough. Mark made an excellent point. Steve made a rebuttal and there's nothing more to say in this discussion. Now we'll go back to MECA and perchlorates.

This was a thread for speculation - not arguments.

Steve and Reed - if you want to start a fight - do it somewhere else. Several of your posts ( and a few others ) have been culled.

This is a thread, as Dan says, for MECA and perchlorate, not semantics.


Doug

From LiveScience.com

On Craig's latest Av Week post he writes that NASA will declare Phoenix a success this week. Also he writes:

"The team invited Aviation Week & Space Technology to "embed" here at the Phoenix Science Operations Control Center and attend most of the 14 or so daily meetings to assess the new science results being transmitted 217 million miles to Earth and plan new commands for Phoenix accordingly."

No kidding.

So how do you sum things up here? Craig writes the "White House" bit, the ONLY thing driving speculation - NASA replies beautifully with that release and then presser about nothing "other" than a window into the scientific process (where we get to hear Hecht deliver a clear and concise description of the MECA situation among other things), finally inviting the "offending" publication to embed.

I vote win/win.

Sounds good to me. NASA shows it has nothing to hide, and rewards a "journalist" who at least showed he had lots of passion about this probe.

--Greg

New Scientist has an article yesterday that touches on perchlorate and life: