Phoenix on Mars - Page 18

RGClark · #**511** (**permalink**) 11-August-2008, 06:35 PM

Quote:

Originally Posted by RGClark

This is interesting since one of the Viking Life experiments detected oxygen evolution when the soil was wetted in the experiment. As I mentioned in post #456, perchlorate-metabolizing microbes would be able to do this.
The three biology experiments on Viking were the Labeled Release Experiment, the
Pyrolytic Release Experiment, and the Gas Exchange Experiment. The oxygen evolution was detected by the Gas Exchange Experiment. The Labeled Release Experiment detected CO2 being evolved. Some strains of the microbe do evolve CO2 instead of oxygen. The third experiment the Pyrolytic Release Experiment detects generation of organic molecules by incorporation of atmospheric gases. Some strains of the microbe are able to survive with just CO2 as their sole carbon source. Then the perchlorate-metabolizers could be responsible for the positive life signs seen in all three Viking life experiments.
According to this article the perchlorate-metabolizers have been seen in both the Atacama desert and in Antarctica:

Scientists: Martian soil similar to Chile’s desert.
Perchlorate find still needs confirmation; it wouldn’t rule out habitability.
By Alan Boyle
Science editor
MSNBC
updated 8:11 p.m. ET, Tues., Aug. 5, 2008
"However, some organisms actually thrive on perchlorates and have been enlisted for cleaning up chemical spills. Perchlorate-loving microbes have been found in Chile's Atacama Desert and Antarctica — two of the places that have been compared to the Red Planet's cold, dry environment."
http://www.msnbc.msn.com/id/26043028/

Then tests of the soils from these sites containing the perchlorate-metabolizers with analogs of the three Viking life experiments may show that life is indeed possible as an explanation of the Viking Mars-life experimental results.

Bob Clark

The possibility of the perchlorate-metabolizing microbes being present might have a bearing on TEGA's failure to detect free chlorine to confirm the presence of perchlorate. The TEGA scientists looked only for chlorine gas. This was based on the fact that free oxygen was detected from one of the samples. However, the perchlorate-metabolizing microbes release oxygen in reducing perchlorate to chlorate, then chlorite, then chloride. Then what might be needed to search for instead might be one of these compounds. This would require TEGA being programmed to seach for them specifically since in its normal mode of operation it does not do a wide spectrum search but focuses on only certain expected compounds only.

Bob Clark

JonClarke · #**512** (**permalink**) 11-August-2008, 11:08 PM

Actuaally TEGA did find indicators of perchlorate in the first sample, but not the second. As the second sample was from a grater depth the most parsimonious explanation is that it is present near the surface. This is consistent with what we find in the Atacama..

There is no need to posulate percholorate consuming organisms at this stage.

Jon

01101001 · #**513** (**permalink**) 12-August-2008, 03:04 AM

Sol 76 Raw Images have begun to arrive. So far, there's about 15 images, from the optical microscope and of the sun.

Looks like they might be lining up a shot, for future delivery, at TEGA oven #7, from Robot Arm Camera and from Surface Stereo Imager left:

Low-calorie links. Now with zero trans fats:
NASA Phoenix Mission
University of Arizona Phoenix Mars Mission
University of Arizona Phoenix Mars Mission: Lander Gallery
JPL Phoenix Mission News
NASA Phoenix Twitter Feed
NASA Phoenix Multimedia
CSA Phoenix Mars Mission
Planetary Society: Phoenix Mission
Planetary Society: Phoenix Non-SSI Raw Images
Planetary Society: Phoenix Sol-By-Sol Summary
Planetary Society: Weblog
Emily Lakdawalla Ustream video chat (Wednesdays)
Texas A&M University Phoenix SSI Raw Images Directory
Unmanned Spaceflight Forum: Phoenix 2007/8
Google Mars landing site
NASA TV (or NASA TV Yahoo! source or high-resolution)
NASA TV Media Channel

RGClark · #**514** (**permalink**) 12-August-2008, 09:34 AM

Quote:

Originally Posted by JonClarke

Actuaally TEGA did find indicators of perchlorate in the first sample, but not the second. As the second sample was from a grater depth the most parsimonious explanation is that it is present near the surface. This is consistent with what we find in the Atacama..

There is no need to posulate percholorate consuming organisms at this stage.

Jon

To be more precise what TEGA found in the first sample was oxygen. But that raises a question I wanted to ask. Could TEGA be programmed to do perchlorate detection directly?
If so, then an interesting fact is that by determining the isotope fractionation of the chlorine in the perchlorate we may be able to determine whether biologically mediated reactions were taking place:

Microbial Isotopic Fractionation of Perchlorate Chlorine.
Max L. Coleman,1* Magali Ader,1,2 Swades Chaudhuri,3 and John D. Coates4
"Perchlorate contamination can be microbially respired to innocuous chloride and thus can be treated effectively. However, monitoring a bioremediative strategy is often difficult due to the complexities of environmental samples. Here we demonstrate that microbial respiration of perchlorate results in a significant fractionation (∼−15‰) of the chlorine stable isotope composition of perchlorate. This can be used to quantify the extent of biotic degradation and to separate biotic from abiotic attenuation of this contaminant."
Appl Environ Microbiol. 2003 August; 69(8): 4997–5000.
http://www.pubmedcentral.nih.gov/art...i?artid=169092

I've read that one intended purpose of TEGA on Phoenix was to determine isotope fractionation of sulfates, for example, so it may have the capability to do this for chlorine.

Bob Clark

01101001 · #**515** (**permalink**) 12-August-2008, 04:35 PM

Sol 77 Raw Images began arriving a few minutes ago.

Procyan · #**516** (**permalink**) 12-August-2008, 08:15 PM

Does that mean that if no bugs are present, the 37Cl/35Cl ratio in Martian ClO4- rich soil should be the same as the isotope ratio for chloride? And if they are not the same, if the lighter isotope is enriched in Martian chloride soil samples, then it argues for microbial selection of 35Cl? That sounds so doable with TEGA . I hope they feel they can spare an oven to zero in.

Also (pardon my floods of questions), but I didn't quite understand the paper regarding naturally altered Cl ratios. Can one distinguish microbial from naturally fractionated isotopes?

John Jones · #**517** (**permalink**) 12-August-2008, 08:28 PM

Quote:

Originally Posted by Procyan

Does that mean that if no bugs are present, the 37Cl/35Cl ratio in Martian ClO4- soil should be the same as the isotope ratio for chloride? And if they are not the same, if the lighter isotope is enriched in Martian chloride soil samples, then it argues for microbial selection of 35Cl? That sounds so doable with TEGA . I hope they feel they can spare an oven to zero in.

Also (pardon my floods of questions), but I didn't quite understand the paper regarding naturally altered Cl ratios. Can one distinguish microbial from naturally fractionated isotopes?

Good question.

JonClarke · #**518** (**permalink**) 12-August-2008, 11:20 PM

Apparently so.

http://www.agu.org/meetings/fm06/fm0...fm06_V14C.html

See abstract 4.

Whether TEGA can do this I don't know. It would depend on the design of the MS and the amount of chlorine, I suspect.

Jon

01101001 · #**519** (**permalink**) 13-August-2008, 02:02 AM

Aviation Week: Phoenix Lander Mission Deemed A Success (by Craig Covault):

Quote:

The Phoenix Mars lander and its science and operations teams at the University of Arizona and NASA's Jet Propulsion Laboratory (JPL) will reach key milestones this week, including an official determination by NASA that the mission is a complete success.

Most of the Phoenix team also will shift to Earth time, instead of making the daily adjustments to local Mars time at the Phoenix arctic landing site that forces team members to work through the middle of their nights.

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.

Designating the mission a success means it has completed key contractual and scientific goals with plenty of margin remaining in its systems for additional imaging, wet chemistry and microscope tests, and for the continued search for organics by its organic chemistry instrument.
[...]

No more White House briefings...

Procyan · #**520** (**permalink**) 13-August-2008, 02:27 AM

Running on a bit, if chloride is scarce ( ppm?) but perchlorate is plentiful then the Martians are light eaters. Unless the chloride is somehow removed from the soil. Many ammonium salts are volatile including ammonium chloride.

Hmmm, solid state life forms, metabolizing solid perchlorate salts and excreting ammonium chloride gas. Takers? As much as I WANT there to be bugs, I can't quite see it.

I know this is beyond Phoenix, but could a sample of Martian methane show similar fractionation of carbon isotopes? Do earthly methanogens like 12 more than 13?

Maybe the bugs live deeper underground where radioactive decay keeps everything nice and toasty. That I can swallow.

01101001 · #**521** (**permalink**) 13-August-2008, 02:11 PM

I need a new trench map. Texas A&M University Phoenix SSI Raw Images Directory is listing new names:

Quote:

Sol 078: Image Snow White after cleaning, document Stone Soup dig, possible pre-sample doc in Burn-Alive; remote sensing

Sol 077: Document Burn Alive deepening and Upper Cupboard widening; remote sensing

Sol 076: Document Stone Soup dig (Dodo-Goldi-Stone-Cupboard?), TA7 delivery pose; remote sensing

Sol 075: MRO-coordinated remote sensing, document Burn-Alive dig and WW delivery to OM

Sol 074: Document "Stone Soup" trench (because Dodo, Goldilocks, Upper and Lower Cupboard aren't enough names for 1/4 square meter of Mars) and Wicked Witch 2 sample acquisition for OM; remote sensing

We had four trenches, left to right: Dodo-Goldilocks, Cupboard (which now is Upper Cupboard and Lower Cupboard), Neverland, and Snow White.

New is Stone Soup, I think near Dodo and Cupboard. New also is Burn Alive, and I haven't figured out where that is yet (but it is scheduled for imaging with sol 78). At least we know it's only a robot arm's length away.

Squink · #**522** (**permalink**) 13-August-2008, 09:55 PM

Quote:

Originally Posted by Procyan

metabolizing solid perchlorate salts and excreting ammonium chloride gas. Takers?

Well, what with ammonium chloride having a melting point of around 338°C, I think not.

John Jones · #**523** (**permalink**) 13-August-2008, 10:26 PM

Quote:

Originally Posted by Squink

Well, what with ammonium chloride having a melting point of around 338°C, I think not.

I wondered about that, but was too preoccupied to look it up.

Ammonia and hydrogen chloride are are volatile, and form ammonium chloride in moist air which deposits all over my lab.

But I never heard that ammonium chloride was volatile.

Swift · #**524** (**permalink**) 13-August-2008, 11:10 PM

Quote:

Originally Posted by John Jones

But I never heard that ammonium chloride was volatile.

From this BASF webpage on ammonium chloride

Quote:

All the products undergo sublimation on heating. At 335 °C ammonium chloride vapour is completely decomposed into ammonia (NH3) and hydrogen chloride (HCl).

Vapour pressure (30 °C)
1.3 mbar

Vapour pressure (250 °C)
67 mbar

So yes, particularly above ambient, it has a pretty high vapor pressure.

01101001 · #**525** (**permalink**) 14-August-2008, 04:06 AM

The Planetary Society Weblog:
Phoenix sol 76 update: Digging at Neverland, Cupboard, Stone Soup, Snow White, Burn Alive; samples for microscope and TEGA 5; and more

Quote:

So here is an attempt to do a whirlwind update of the last two weeks on the mission. To set the stage: on Mars, it is now sol 78, just two weeks shy of the end of the nominal mission. The last images I have to work with are from sol 76.

Yay: A new trench map.

Quote:

During these all-night observations they are also starting to look for transient frost forming on the surface.

Quote:

Stone Soup is below Dodo-Goldilocks and Upper Cupboard. At Stone Soup, Ray said, they predict they will be able to dig much deeper than elsewhere, because it is inside the trough between the polygons. If they do manage to dig down 10-15 centimeters or so, this is the possible location for the next Wet Chemistry Laboratory sample.

Quote:

Ray told me that they are actually not sure yet whether they will use Stone Soup for the next Wet Chemistry Laboratory Sample. It depends upon what happens in Upper Cupboard. Ray explained that they plan to stick TECP into the ice in Upper Cupboard to see if, over the course of the day, there is any melting of the ice. Then they plan to get some ice-rich soil from Upper Cupboard and stare at it in the scoop divot to see if it sublimates, and if it does, if it leaves any salt behind. If it melts (which would require the presence of salt) and if it leaves a salty residue when it sublimates, then they will change the plan and get the next Wet Chem sample from an ice-rich area of Upper Cupboard. If, however, they see no evidence for salt, they'll proceed with the Wet Chem sample from Stone Soup.

First sunset on approximately sol 94.

Lots, lots more there.

01101001 · #**526** (**permalink**) 14-August-2008, 04:12 AM

Sol 78 Raw Images began arriving about 10 minutes ago. About 50 so far.

RGClark · #**527** (**permalink**) 14-August-2008, 01:38 PM

Review of the controversy about the sensitivity of the Viking GCMS sent to Mars to detect organic molecules:

Secrets of the martian soil.
Corinna Wu
Nature, 16 Aug 2007, p 742-744 v 448.
"Navarro-González was inspired to revisit the Viking tests for organic molecules after the exploratory rover Opportunity discovered jarosite, a hydrated iron sulphate that forms in the presence of water, on Mars in 2004. Studying jarosite-containing soils in the Rio Tinto area of Spain he found that getting organic material out using chemical approaches was relatively easy — but getting it out just by heating was not. “When I repeated the Viking experiments, “ he says, “I was surprised to see that despite the huge amount of organic matter present, there was virtually no detection of organics in the sediments. This was quite strange.” Independently, McKay had been doing research on soils from the Atacama desert in Chile, and had also started to suspect that the Viking experiments weren’t telling the whole story. Alison Skelley, a graduate student at the University of California, Berkeley, had asked McKay to review a paper on a device she had developed for detecting amino acids in soil3.
McKay found the paper striking. “It found that there were a thousand times more amino acids released by chemical extraction than pyrolysis” — the heating method used by the Viking experiments. Then McKay says, “Within a month, Rafael told me about his puzzling result with the jarosite. That’s when I suggested that we ought to see if this effect was widespread.”"
...
"Heated debate."
"Navarro-González and McKay think that during the heating step of the Viking experiment, any organics given off at moderate temperatures would have been turned into CO2 before they reached the GC-MS, thanks to catalytic iron compounds in the Martian soil. “We suggest that a small portion [of the carbon dioxide seen by the Viking experiments] could have resulted from the oxidation of organics,” says Navarro-González. “Even if it’s just a small percentage, this could mean levels of organics on the surface of Mars a thousand times higher than expected.”"
http://www.mediabistro.com/portfolio...Ee4129Gees.pdf

Bob Clark

01101001 · #**528** (**permalink**) 14-August-2008, 07:49 PM

First AFM image

JPL Phoenix Mission News: Phoenix [Atomic Force] Microscope Takes First Image of Martian Dust Particle (August 14)

Quote:

NASA's Phoenix Mars Lander has taken the first-ever image of a single particle of Mars' ubiquitous dust, using its atomic force microscope.

The particle -- shown at higher magnification than anything ever seen from another world -- is a rounded particle about one micrometer, or one millionth of a meter, across. It is a speck of the dust that cloaks Mars. Such dust particles color the Martian sky pink, feed storms that regularly envelop the planet and produce Mars' distinctive red soil.

"This is the first picture of a clay-sized particle on Mars, and the size agrees with predictions from the colors seen in sunsets on the Red Planet," said Phoenix co-investigator Urs Staufer of the University of Neuchatel, Switzerland, who leads a Swiss consortium that made the microscope.
[...]

01101001 · #**529** (**permalink**) 14-August-2008, 09:36 PM

Sol 79 Raw Images have begun arriving.

Edit: Expect a TEGA door to open. Or, at least expect an attempt to open one of those sometimes-sticky TEGA doors (according to a label at Texas A&M University SSI Sol 79 Raw Images).

01101001 · #**530** (**permalink**) 15-August-2008, 05:41 AM

Quote:

Originally Posted by 01101001

Sol 79 Raw Images have begun arriving.

Edit: Expect a TEGA door to open. Or, at least expect an attempt to open one of those sometimes-sticky TEGA doors (according to a label at Texas A&M University SSI Sol 79 Raw Images).

If I engage full imagination, and brighten it up, in this I can almost picture oven #7, nearest end, far side, with the closest door open fully and the other open partially, a mirror image of oven #4 doors, the first opened.

RGClark · #**531** (**permalink**) 15-August-2008, 01:13 PM

Quote:

Originally Posted by 01101001

First AFM image

JPL Phoenix Mission News: Phoenix [Atomic Force] Microscope Takes First Image of Martian Dust Particle (August 14)

Quote:

"This is the first picture of a clay-sized particle on Mars, and the size agrees with predictions from the colors seen in sunsets on the Red Planet," said Phoenix co-investigator Urs Staufer of the University of Neuchatel, Switzerland, who leads a Swiss consortium that made the microscope.

Maybe it is clay. That is the impression you get from the particles in the optical microscope images:

http://www.nasa.gov/images/content/2...te_516-387.jpg

Bob Clark

01101001 · #**532** (**permalink**) 15-August-2008, 04:31 PM

Quote:

Originally Posted by 01101001

If I engage full imagination, and brighten it up, in this I can almost picture oven #7, nearest end, far side, with the closest door open fully and the other open partially, a mirror image of oven #4 doors, the first opened.

Someone at UMSF brightened it up, in article in topic TEGA - Round 2, and came to the same conclusion: outboard door open fully, inboard door open partially. Should have no trouble getting icy soil into oven -- pending solution to stickiness problem.

Even better, further on in the topic, slinted nails it with an animation of before and after.

RGClark · #**533** (**permalink**) 15-August-2008, 05:37 PM

The Planetary Society Weblog
By Emily Lakdawalla
Phoenix sol 76 update: Digging at Neverland, Cupboard, Stone Soup, Snow White, Burn Alive; samples for microscope and TEGA 5; and more.
Aug. 13, 2008 | 16:07 PDT | 23:07 UTC

Quote:

One more random item: I asked Mark when Phoenix is going to see its first sunset. He said: "Center of the Sun hits the ideal horizon for the first time sol 92. That makes the first grazing ~90/91 and the first setting ~94. The true visible horizon is ~0.5 degrees higher due to the hill to the northwest (haven't checked the 0.5 deg figure that closely). That advances things by 5 sols. I haven't factored in the possibility that first setting is after midnight due to the terrain slope. We should do some midnight imaging sol 79/80 [i.e. they are planning that right now to take place overnight nextersol]. This will be nice in itself, but will also confirm the details of the timing. It is not clear which nights we'll have the ability to follow up and look for a sun set. Starting sol 84, we've agreed to rein in our appetites for 'night' observations."

http://www.planetary.org/blog/article/00001603/

Then perhaps TEGA samples can be taken near the end of the nominal mission when it will be dark and temperatures will be lower and ice can be collected without it melting.

Bob Clark

01101001 · #**534** (**permalink**) 15-August-2008, 06:57 PM

Sol 80 Raw Images are hot and fresh -- but there's only 3 so far, and they're atmosphere and sun.

Eight minutes after local midnight, a very low midnight sun:

Procyan · #**535** (**permalink**) 15-August-2008, 10:29 PM

I couldn't help but freeze dry some salt solutions. I dried 70 ml aliquots of 0.1, 1 and 10% NaCl in distilled water. Also tap water. The liquid depth was 18 mm. My aim was to get an idea of what sort of residue we could look for in a Mars sublimation sequence.I took a photo but the size is 500K. But the limit is 146 for a JPEG.

Not sure if I can post it or even should. Just for fun really. Can I attach it anyway?

John Jones · #**536** (**permalink**) 15-August-2008, 10:55 PM

Quote:

Originally Posted by Procyan

I couldn't help but freeze dry some salt solutions. I dried 70 ml aliquots of 0.1, 1 and 10% NaCl in distilled water. Also tap water. The liquid depth was 18 mm. My aim was to get an idea of what sort of residue we could look for in a Mars sublimation sequence.I took a photo but the size is 500K. But the limit is 146 for a JPEG.

Not sure if I can post it or even should. Just for fun really. Can I attach it anyway?

WHat did you use to freeze-dry them?

JonClarke · #**537** (**permalink**) 15-August-2008, 11:20 PM

Quote:

Originally Posted by Procyan

I couldn't help but freeze dry some salt solutions. I dried 70 ml aliquots of 0.1, 1 and 10% NaCl in distilled water. Also tap water. The liquid depth was 18 mm. My aim was to get an idea of what sort of residue we could look for in a Mars sublimation sequence.I took a photo but the size is 500K. But the limit is 146 for a JPEG.

Not sure if I can post it or even should. Just for fun really. Can I attach it anyway?

Nice work! Can you reduce the size of the image, either by reducing the resolution or cropping to a feature of interest?

Jon

Procyan · #**538** (**permalink**) 15-August-2008, 11:29 PM

A small Dura-Dry lab unit. W/ shelf heat and sample TC probe.

John Jones · #**539** (**permalink**) 15-August-2008, 11:43 PM

Quote:

Originally Posted by Procyan

A small Dura-Dry lab unit. W/ shelf heat and sample TC probe.

Is that the same as a lyophilizer? One of my sister-labs had one of those, but I never got to play with it.

Procyan · #**540** (**permalink**) 15-August-2008, 11:55 PM

Hope I didn't over do it. Image down to about 28 k now! Yes it is identical to lyophilization.

starting at bottom left is tap water, our water is known to be high in calcium scale. the others are labled. I did note that the 10 % sample froze solidly initially at -30 C, but started to melt when I applied shelf heat. I incremented the heat up slowly to 30 C. It seemed to melt about 8 C and then refroze as it boiled. I waited about 30 min. then incremented up to 30 C.

I wanted to show how the pure water ice separates from the high salt ice. To me the interesting sample is the high salt one. Both it and the 1 percent sample showed pockmarked surfaces as they dried.

Also, in a separate experiement I froze a sample of saturated brine under vacuum to -30 C. I released the vacuum and dropped it on the countertop and a about 20 percent of thevolume spilled out of the interior as liquid. The rest stayed frozen for a time. Brines on Mars could be interesting.

I used a black marker to darken 1/2 the bottom of the sample pans

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