Phoenix science results

JonClarke · Nov 12, 2008

I thought I would start this thread to discuss the Phoenix science results.  Firsly because the mission is over and secondly there seem to be a bunch of people out there who seem to thik that Phoenix achieved very little.I suggest that the thread should contain links to interesting stroies, conferences, papers etc., and discussion therof.To start with there is the American Geophysical Union Conference in December.Go here:http://www.agu.org/meetings/fm08/waisfm08.htmlEnter "Phoenix," set limits to "100", and hit “fetch documents” you will extract some 61 abstracts, of which 44 for Phoenix mission related.  Almost every aspect of the mission is covered.You can also link to specific abstracts of interest, which I suggest is what we do for discussion.Jon <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

silylene old · Nov 12, 2008

Replying to: <DIV CLASS='Discussion_PostQuote'>I thought I would start this thread to discuss the Phoenix science results.  Firsly because the mission is over and secondly there seem to be a bunch of people out there who seem to thik that Phoenix achieved very little.I suggest that the thread should contain links to interesting stroies, conferences, papers etc., and discussion therof.To start with there is the American Geophysical Union Conference in December.Go here:http://www.agu.org/meetings/fm08/waisfm08.htmlEnter "Phoenix," set limits to "100", and hit “fetch documents” you will extract some 61 abstracts, of which 44 for Phoenix mission related.  Almost every aspect of the mission is covered.You can also link to specific abstracts of interest, which I suggest is what we do for discussion.Jon Posted by jonclarke</DIV> Thank you Jon.  I wonder if any of the 'naysayers' ever read journals, or go to conferences.  Unless they see many grand panoramic color photos made with megapixel arrays from a moving rover, they will always be disappointed. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center">- - - - - - - - - - - - - - - - - - - - - - </div><div class="Discussion_UserSignature" align="center">I really, really, really miss the "first unread post" function. </div> </div>

robnissen · Nov 12, 2008

Replying to: <DIV CLASS='Discussion_PostQuote'>Thank you Jon.  I wonder if any of the 'naysayers' ever read journals, or go to conferences.  Unless they see many grand panoramic color photos made with megapixel arrays from a moving rover, they will always be disappointed. Posted by silylene</DIV> I don't need megapixel arrays, but I would have preferred more systematic release of information from Nasa.  There are a lot of things that I do not know about Phoenix and I am at least more informed than the general public.  Does anyone know the answers to the following questions:1.  Was perchlorate only found in one sample.  IIRC, there was a conflict between the early samples regarding whether and how much perchlorate was present.  Was this conflict resolved with later samples?2.  How many of the ovens were eventually used? 3.  Related to 2, what was the preliminary science result for each oven that was used?  For example, at least one of oven tests found liquid water.  Did any of the others?

JonClarke · Nov 12, 2008

Replying to: <DIV CLASS='Discussion_PostQuote'>I don't need megapixel arrays, but I would have preferred more systematic release of information from Nasa.  There are a lot of things that I do not know about Phoenix and I am at least more informed than the general public.  </DIV>The releases are as systematric as is possible with the resources available.  Phoenix had a much higher media presence that the rovers.  But people still complainReplying to: <DIV CLASS='Discussion_PostQuote'>Does anyone know the answers to the following questions:1.  Was perchlorate only found in one sample.  IIRC, there was a conflict between the early samples regarding whether and how much perchlorate was present.  Was this conflict resolved with later samples?</DIV>Several samplesReplying to: <DIV CLASS='Discussion_PostQuote'>2.  How many of the ovens were eventually used? </DIV>Seven ovens were filled, 6 with soil, one with the organic free bank.  All soil samples were cooked, no need to cook the OFB as no organics were found.Replying to: <DIV CLASS='Discussion_PostQuote'>3.  Related to 2, what was the preliminary science result for each oven that was used?  For example, at least one of oven tests found liquid water.  Did any of the others?  </DIV>Results are still being analysed.  Real life science is not like a TV show with instantaeous results, it can take  weeks, months, even years of analysis.   <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

JonClarke · Nov 13, 2008

I have downloaded all the AGU abstracts and am going through them.  I will post summaries of and links to the ones I find most interestin in the next couple of days.Jon <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

MeteorWayne · Nov 13, 2008

Replying to: <DIV CLASS='Discussion_PostQuote'>I have downloaded all the AGU abstracts and am going through them.  I will post summaries of and links to the ones I find most interestin in the next couple of days.Jon Posted by jonclarke</DIV> Thanx, I'm still working my way through the list!! <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

JonClarke · Nov 28, 2008

The mission summary abstract.Phoenix landed on the fluidised ejecta of Heimdal crater.  Chemistry is alkaline, with calcium carbonate associated with the ice.  This contrasts with the two MER sites. A "suprisingly large amount" of perchlorate was seen, most likely magnesium perchlorate.The MI saw three types of particles, a clay-sized fraction which was iron rich and two types of larger partciles, possibly of clay and carbonate.The Phoenix Mission Explores the Martian Arctic <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

JonClarke · Nov 28, 2008

The Phoenix site is unique compared to previous sites because of the very young ejecta and icy composition.Very few aeolian features were seen, either ventefacts or ripples.The soil cover is composed of sandy silts of basaltic composition and iron-rich dust.  there is a contribution from water altered material.The soil is cloddy and stuck to the spacecraft, probably through electrostatic effects.The surface lag is probably formed by the sublimation of icy material.Geologic Setting and Soil Physical Properties of the Mars Phoenix Landing Site <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

JonClarke · Nov 28, 2008

The surface rock population is dominated by pebbles (>10 cm), more than could be expected from simple crushing (i.e. by impact).  this suggesting sorting processes in the fluiised ejecta from Heimdall crater.The Phoenix site is distinctly less rocky than Gusev in all size ranges.Polygon centres have fewer rocks than troughs, the rocks in ploygons are evenly spaced.  These suggest the polygons are actively redistributing rocks through thermal cryoturbation.Size-Frequency Distribution of Rock Clasts at the Phoenix Landing Site <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

JonClarke · Nov 28, 2008

Nano-phase ferric oxide detected on soils and rocks.  This was expectedNo olivine spectra detected in sands, unlike at Gusev.  This means that the dust, although basaltic in composition, was quite weathered.Albedo varied markedly acording to tie of day.Ice spectra showed water ice and were highly varibale, showing varying amounts of fine-grained ferri-oide dust.  The spectra also changed with time as the ice sublimated.  Optically thick (300 micron) lags deveoped on Snow White in two sols.Time-Dependent SSI Multispectral Properties for Rock, Soil, Ice, and Sublimation Lags at the Phoenix Landing Site on Mars <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

JonClarke · Nov 28, 2008

The high latitude regolith is a substantial ice resevoir and plays as significant role in the seasonal water cycle.The landing site is withing the season CO2 cap, and engery balance measurements is critical to understand volatile cycling.The measured thermal inertia of the surface was much higher than that determined from orbit (this shows the importance of ground truth - JC) and is out of equilibrium with the ice.Atmospheric water partial pressures are variable during the day over 2 Pa.  The variability disappears at night and the partial pressure then tracks the falling temperatures. The temperature dependent behaviour begins before either soil or atmosphere reach the frsot point, indicating that ice does not play a role.  Exchange of hydrogen-bonded water is indicated by the enthalpy.Regolith-Atmosphere H2O Exchange and Surface Energy Balances at the Phoenix Landing Site <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

JonClarke · Nov 28, 2008

Phoenix detected anophase iron oxide, water ice, carbonates, and possible phyllosilicates (clays).Ice was in two forms, relatively pure ice segregations and as ice rich soil.  ice was detected obserbation of sublimation behaviour,, reflectance spectrum, and scanning caliometry indacting phase transition as close to 0 degrees, accompanied by evolution of water vapour.Carbonate was detected by an endothermic transition at ~700 degrees accompanied by CO evolution.Clays were suggested by an enthothermical expulsion of water at 700-800 degrees and an exotermic transition at 880 degrees.No SO2was thermally evolved, suggesting late of sulphate minerals.The alkaline soil supports the presence of carbonates, whch appear concentrated at the soilice boundary.The presence of clays and carbonates strongly supports that the site may have experienced habitable conditions.Preliminary identification of minerals at the Mars Phoenix Landing Site <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

JonClarke · Nov 28, 2008

A  mechanism for polygon formation by the build up and loss of the seasonal CO2 cap is suggested.As the CO2 cap forms it freezes the surface stones in place.  The underlying soil continues to contract, however, as temperatures fall.When sublimes the underlying soil continues to expand, and the surface rocks can move with it.  Thus surface rocks are preferentially moved from the polygon centres to the troughs.The presence of stones in the centre of polygons suggests that they are also being brought up from depth.  Asstones in the cracks and troughs will become buried, there is a cycling of pebbles through the regolith. The soil at the Phoenix site is dynamic, with surface added material being buried, new materials being brought up from depth, and other material being cycled from depth to surface and back again.The Role of a Winter CO2 Ice Mantle in the Formation of Patterned Ground at the Phoenix Landing Site <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

3488 · Nov 28, 2008

Regolith has the same PH as Earth's oceans (8.175).Rocks are small, mostly small stones with some larger rocks here & there. A largish boulder approx 1 metre tall was seen approx 300 metres away at Azm 151.58 degrees. Likely to be Heimdall Crater ejecta.The few rocks appeared to form two camps. One looked very volcanic, dark & pitted with what may be vesicles, remarkably similar to those seen by Viking 2 in Utopia Planitia & MER A Spirit in Gusev Crater (visual clues only) & the other, much lighter toned often flat topped, similar to many seen by Mars Pathfinder in Ares Vallis. Atmospheric pressure dropped sol by sol slowly to 7.3 MB as the CO2 was condensating on the South Polar cap, but appeared to stop around Sol 120. Shortly after this, frost became more prevalant. Also dust storm activity rose significantly towards the end of the mission, ushering in a change of season.  Andrew Brown. <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

JonClarke · Nov 28, 2008

No sulphates, cabonates, nitrates or clays were seen in orbiter spectra of the Phoenix landing site.,even with the high resolution CRISM insturment  However the lander detected carbonates and clays (this again is why ground truth is important - JC).Although the lander did not see any residual winter ice,orbiter observations did show it persisted in the earby unmaed 6 km crater and the largestr 10 km Heimdall craterCoordinated Orbital and Landed Observations for Understanding Martian Soil and Rock Mineralogy and Textures <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

JonClarke · Nov 28, 2008

Perchlorate was detected alomost immediately the sample was added to the WCL, a three orders of magnitude response.Perchlorates are described as highly water soluble, deliguescent, and some are powerful freezing point depressors,l owering the freezing point to as low as -70 (some other abstracts said -68).The buffering reponse on addition of acid attributed to carbonate is also mentioned.Discovery of Perchlorate at the Phoenix Landing Site <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

JonClarke · Nov 28, 2008

Pike (from Imperial Collge, Andrew) and his team report that:Almost all samples fall into three categories - 1) Subrounded, strongly magnetic grains of either rough and glassy appearance or varying from yellow to red, brown, and black.  These are roughly fine-sand sized (50-100 microns). These make up 10% of the sample and are magnetic grains in varying stages of decomposition.2) Small (a few microns) white grains making up only 0.5%, and interpreted as being a pale mineral (perhaps carbonate - JC) or salt.3) The remainder is madeup of orange yellow dust that forms agglomerates.  Dust particel abundances increase with decreasing grainsize down to the 4 micron limit of the opitlca microscope. The atomic force microscope confirms that particles continue down to the sub micro scale, these smallest grains are often flattened and have the morphology of clays.  The dust probably represents the most degraded fraction.Microscopic Investigation of Martian Soil Samples at the Phoenix Site <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

JonClarke · Nov 28, 2008

Trenching exposed bright, hard material in the Goldilocks and Snow White trenches.  The visible-NIR spectra of the Goldilocks bright material wasconsistent with slightly dusty ice, but the hard material in Snow White was indistinguishable from soil.The disappearance in 3 sols of a 2 cm chunk of material in Goldilocks was consistent with a sublmation rate of 100 microns per hour. This material is interpreted as localised segregated ice. The reasoning is as follows: the material is hard, localised, has distinct edges, and was initially covered with only 3 cm of soil, thus was 2cm shallower than the hard layer in the Snow White trench. A trench dug 40 cm further south of Goldilocks and with similar orientation, reached 18 cm depth without encountering hard material. The hard material at the bottom of Snow White is probably the ice table.Possiblemechanisms for emplacement of segregated ice include: liquid water pooled into a thermally-produced crack (as in  terrestrial ice wedges), snow particles depositing preferentially in the troughs, and vapor deposition preferentially into cracksThe WCL results indcate the probable presence of Mg(ClO4)2. MI examination of sublimation residue found stickier and more cohesive materials than previous soil samples and light colored particles up to 30 microns. Thes is  suggestive of possible salts more concentrated in this area. Possible Segregated Ice at the Phoenix Landing Site: Was Liquid Water Involved? <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

JonClarke · Nov 28, 2008

A bright smooth substrate was exposed beneath the Phoenix lander at a depth of 10 cm.Snow Queen was imaged on sols 4, 5, 6 and 21 with no obvious changes detected. It was next observed on sol 45, 24 sols after the previous observation. This time clear changes were seen. Several small cracks, most likely due to thermal cycling and sublimation of ice appeared. Nevertheless, the bulk of the surface remained smooth. The next image of Snow Queen was were visible.Snow Queen was next imaged on sol 73. This time its appearance was dramatically changed. The surface had become much rougher and many cracks of at least 1 mm depth and 10 cm long had become evident. The surface colour was now no longer different from that of the surrounding soil. This observation is compatible with the ice table sublimating away.Sublimation of Exposed Snow Queen Surface Water Ice as Observed by the Phoenix Mars Lander <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

JonClarke · Nov 28, 2008

The MECA Wet Chemistry Laboratory (WCL) analyses on the Phoenix Mars Lander have provided the first direct evidence of the soluble components of martian soil. The analyses reported in the abstract were performed on samples acquired from the surface (Rosy Red) and at the soil/ice interface approximately 4-5 cm under the surface (Sorceress). The major cations identified and quantified to date included Na+, K+, Mg2+, and Ca2+, while the anions included Cl- and ClO4-. Sulfate analysis was performed using a Ba2+ titration method. Although carbonate and bicarbonate were not directly measured, their presence and quantification is supported by the alkaline pH, its buffering capacity, common ion effects, conductivity, and the modeled equilibrium species distribution. The Aqueous Chemistry of the Soils at the Phoenix Landing Site <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

JonClarke · Nov 28, 2008

Particles collecting on different strength magnets mounted on Phoenix and examined under the microscope gives iinformation about the magnetic properties of airborne particles, dust disturbed by the landing rockets, and sample surface materials.The results indicate that the dark magnetic particles are most likely magnetite, which has undergone varying degrees of degradation.Phoenix Magnetic Properties Experiments Using the Surface Stereo Imager and the MECA Microscopy StationThis is the last AGU abstract I will report on.  Others can post more if they are interested. <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

3488 · Dec 1, 2008

Replying to: <DIV CLASS='Discussion_PostQuote'>No sulphates, cabonates, nitrates or clays were seen in orbiter spectra of the Phoenix landing site.,even with the high resolution CRISM insturment  However the lander detected carbonates and clays (this again is why ground truth is important - JC).Although the lander did not see any residual winter ice,orbiter observations did show it persisted in the earby unmaed 6 km crater and the largestr 10 km Heimdall craterCoordinated Orbital and Landed Observations for Understanding Martian Soil and Rock Mineralogy and Textures Posted by jonclarke</DIV>Great to have you back Jon. Also frost was observed by MRO HiRISE in Phoenix's location right up to only 10 sols prior to Phoenix's arrival. Phoenix literally just missed it. I'll have to check up that unnamed 6 km wide crater, sounds interesting. I was aware that it was there, but did not know that it maintained frost. That's true about ground truth. There is really quite nothing as effective as getting eqipment onto any planetary surface.Whilst spectroscopy from orbital / flybys etc has improved enormously, i.e Cassini with the moons of Saturn, MRO, MO & MEX with Mars & Phobos & MESSENGER with Mercury, there is no substitute for getting intruments to sample, regolith & ice directly & for a camera to look around at human height & lower & examine the surface topography, landforms & rock distribution. Not to mention equipment to study the weather & possibly also to study seismology (though nothing since Viking 2 has landed seismometers on Mars & even the Viking seismometers never worked properly, V1 not at all). To understand a planetary body properly IMO, both orbiters & landers are needed.  Andrew Brown.  <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

JonClarke · Dec 1, 2008

It's good to be back!  Frost was probably important too, I scanned the meteorology papers but did not see a mention.  But it is early days. I assume the 6 km crater is the one in the 7 o'clock position relative to Heimdall in this map<img src="http://sitelife.space.com/ver1.0/Content/images/store/11/11/2bef0745-3b35-431f-9bc2-e674307f551d.Medium.jpg" alt="" />Jon <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

3488 · Dec 1, 2008

Replying to: <DIV CLASS='Discussion_PostQuote'>It's good to be back!  Frost was probably important too, I scanned the meteorology papers but did not see a mention.  But it is early days. I assume the 6 km crater is the one in the 7 o'clock position relative to Heimdall in this mapJon Posted by jonclarke</DIV>Jon, I think that is it. I know there's another one in the top left, but I think that one is too far away. I will investigate. I thought the amazing shot of Phoenix descending on the chute & passing in front of Heimdall Crater from the MRO HiRISE, showed Heimdall to be icy IMO, by looking at the walls. Even if Phoenix was missed, that was one hell of an image, Phoenix on the chute being included was the icing on the cake.Phoenix on chute in front of Heimdall Crater. Phoenix on chute in front of Heimdall Crater & enlarged crop. Another Heimdall Crater Image here. Rim of Heimdall Crater MRO HiRISE. Also Jon, have you seen this?Mars Odyssey THEMIS night time obs of Scandia Colles & Phoenix Landing Ellipse. Andrew Brown.  <div class="Discussion_UserSignature"> "I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before". Linda Morabito on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.http://www.launchphotography.com/ http://anthmartian.googlepages.com/thisislandearthhttp://web.me.com/meridianijournal </div>

JonClarke · Dec 2, 2008

No, I had not seen that, thanks Andrew.Wht I like about the HiRISE image is, at max resolution, you can just see the black dot of the heat shield falling away. <div class="Discussion_UserSignature"> 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 Arthur Clarke </div>

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