I figured it was time for a new thread, since we finally seem to be getting some science results out of Phoenix. The press release should be out shortly.
First numerical result I've heard was given by Peter Smith at today's press briefing at AGU: TEGA found that the soil is composed of 5% calcium carbonate, which is a significant result.
Hopefully more will hit the Web soon -- post here when the links go up!
--Emily
Some AGU related images at the Phoenix site
http://phoenix.lpl.arizona.edu/images.php?gID=0&cID=381
Phoenix Site on Mars May Be in Dry Climate Cycle Phase
I think it's consistent. They saw vapour, they saw films, but they didn't see liquid - I think is the main story.
Doug
From http://planetary.org/blog/ referring to TEGA results from Phoenix:
"For example, they saw a low-temperature release of carbon dioxide (CO2). This could be a number of things: iron or magnesium carbonates; adsorbed carbon dioxide; or potentially most exciting, combusted organics."
"...if there were organics present, they could have been destroyed by the perchlorate during heating before TEGA had a chance to detect them. Unfortunate --..."
Why cannot the calorimeter distinguish between these possibilities? Wouldn't combusted organics be signalled by an exothermic process? Whereas the others would be endothermic, right?
I agree, Marsbug - I also noticed that change in the interpretation of the results and I'm curious about the details too.
If you haven't noticed it, http://phoenix.lpl.arizona.edu/images.php?gID=42612&cID=381 from TECP was presented yesterday. Perhaps this gives us a clue. To my eye there's no clear anticorrelation between the atmospheric and soil measurements - there are peaks in the soil measurement during the day. Perhaps a sign that there's some non-trivial dynamics going on here - more than just a simple "soil at night" and "air during the day" cycle?
I wouldn't describe it as "hopelessly pedantic", just being curious about the scientific process...
Wow, thanks for the cool graph fredk; I am sure my temporal insomnia and headache last night was because of this subject (to detect or not to detect water film, that *was* the bloody question!). The graph clearly shows that the ice is literally breathing. Cool.
That makes a lot of sense marsbug - I like your hunch.
Thanks! I've had a quick look, but I've not found anything relating to the growth of thin water films under matian pressures and temperatures, although http://www.springerlink.com/content/ku730x5321j8m101/ and http://www.springerlink.com/content/h350t61341kl0807/ might have some interest for anyone with access to springer link.
I think it's an experiment someone will be doing at some point in the near future though!
marsbug,
Who's Albert Einstien?
It's a little known fact that there were three brothers, Ienstein, Einstien, and Einstein. Albert was actually their family name (the family had Asian roots). The first two shared the limelight, taking alternate holidays, to preserve some privacy for the family. Albert Ienstein is a character best left unremarked upon....
Or maybe I just made a spelling mistake....
I've always been amused that the American comedian and actor, Albert Brooks, had to change his real name. He just couldn't see himself using his real name -- Albert Einstein. (His brother, who played the idiot character Super Dave back in the 80s, kept his real name, performing under the name Bob Einstein.)
-the other Doug
There's some more on it over on the http://planetary.org/blog/. Thanks Emily! The description of how water adsorption works is excellent, it really clarifies the difference between thin films of water and thin films of liquid water.
This LPSC abstract contains a full list of samples collected by Phoenix - might be useful!
Phil
http://www.lpi.usra.edu/meetings/lpsc2009/pdf/1067.pdf
Interesting (LPSC abstract #2196) that the lack of detection of chlorine in TEGA was likely due to a reaction with the nickel in the TEGA ovens.
Looks like there is someone defending that the droplets seen on Phoenix's legs are made out of...liquid water...
"Nilton Renno from the University of Michigan and Phoenix team member, thinks it could be. "According to my calculations, you can have liquid saline solutions just below the surface almost anywhere on Mars," he said."
Story at http://www.universetoday.com/2009/02/18/has-liquid-water-been-detected-on-mars/#more-25712.
Made a crude animated gif out of the image in the article, although I'm almost sure someone here did one before with higher quality...
http://www.gifninja.com/Workspace/a68a18ab-eb7b-4bb9-9380-b9593c0dc630/output.gif
There's an article on New Scientist about this:
http://www.newscientist.com/article/dn16620
In that article there's a link to this conference abstract:
http://www.lpi.usra.edu/meetings/lpsc2009/pdf/1440.pdf
Oh wait! I get it! Here's a possible mechanism for shrinkage of the remainder:
If the drop was cooling before it merged, then ice would have been crystallizing out of the solution! (refer to simplified phase diagram http://www.lpi.usra.edu/meetings/lpsc2009/pdf/1440.pdf)
The drop would thus be non-uniform, a mixture of solid precipitated ice and salts in solution. I'd assume that the ice crystals would nucleate and form at the surface imperfection of the lander strut. So at the time of merge, the salt solution would be pulled over to the big drop, but most of the ice crystals would stay behind with the remainder.
So at the instant of the merge, the salt concentrations of the remainder and merged drops would be the same.
But after warming, and melting of the upper remainder's ice crystals, the salt concentration would be too dilute! Thus water could evaporate off the upper remainder drop until the preferred equilibrium concentration was reached. The remainder drop would shrink!
-Mike
[Now if I understand this right, it should also be possible to imagine a scenario/conditions where salts would have been precipitating at the time of merge. This would cause a remaining drop to grow faster than expected.]
If this really is liquid water, it would be a tremendous discovery. It seems a pretty hard conclusion to draw from three* monochrome and fairly low resolution images, with theorizing alone to back up the interpretation. I would really like to see laboratory replication of all of the lines of evidence that it is suggested that we observe in these images. For starters, what should be a pretty easy experiment: prepare a candidate perchlorate brine solution and a controlled experiment box which can replicate the temperature and pressure of the martian pole. Spray the brine on a metal pipe and take photographs under various lighting conditions. Compare with the images from Phoenix. Can you make spherules which look the same? Show clearly how to distinguish between lighting changes and motion and growth/shrinkage of droplets. Try doing the same thing with frozen droplets. Is there something that distinguishes the liquid from the frozen droplets in a still photograph? For a more advanced test, try to demonstrate the effects claimed as "smoking gun" signs in Renno et. al.'s abstract: if temperature, pressure, and humidity are varied over a cycle consistent what was observed by Phoenix, droplet growth is suppressed on material left behind by a droplet that merges with a neighbor; droplets grow selectively where the pipe is splashed with perchlorate salts; and their sizes and growth is proportional to their volume.
I'm really excited about the possibility of liquid water on mars today, but extraordinary claims require extraordinary evidence. So far this looks more at the level of (highly educated) speculation than an airtight demonstration of fact.
(*can any of the image guru's tell me if there really are only 3 images of that strut? Or are there more that just weren't selected for the comparison, because lighting conditions differ or something?)
A couple of very good points were made over on the baut forum, Phoenix Mars Results thread that warrant repeating here.
In the few seconds of the landing cycle the environment under the lander was high temperature (1200k) and high pressure Ammonia/Nitrogen from the exhaust. This temperature would have broken down perchlorates and vaporised part of the ice layer. Water vapour and dust mixed with the extremely hydroscopic ammonia provides for some interesting products. We can have no certainty over what the the deposits on the strut are made up of, but a possible ammonia water solution, concentration unknown makes for some interesting possibilities.
But the key point made is that the deposits are an exotic phenomenon attributable to the lander - not the Martian environment, and have no relevance to the Martian environment..
(cr Vincent Chevrier, BrianC and Nilrem on baut)
What has irked me is that the media, and even specialist (should-know-better) media have been pushing this as 'liquid water found on Mars'.
No it wasn't.
It was found on Phoenix. Several hundred pounds of metal and wires that expended most of its energy budget keeping itself warm, having blasted the surface with >1kdegC thruster exhausts. Those droplets tell us very very little about Mars. They tell us about Phoenix.
Doug
Well...it does tell us quite a bit about Mars, actually.
It shows that at least under special surface conditions, atmospheric water can condense (deliquese) onto exposed residual salts.
Can those special conditions also exist naturally on Mars?
How abundant? (thermal inertia of substrata?, regional salt types with similar chemical properties?)
How often? (seasonal?, certain times of day?)
The most similar natural phenomenon to the landing could be the small meteor impacts.
Getting irked at mass media representation of a specialist area where one is better informed than the hacks churning the stuff out is a short-cut to a broken liver!
Today's http://www.spaceflightnow.com/news/n0903/08marswater/ on Spaceflight Now; major paper re liquid water forthcoming? Presented a bit sensationally though, I'm afraid.
It's that man again (Craig Covault), and that http://www.spaceflightnow.com/news/n0903/08marswater/icefull.jpg looks strangely familiar too...
Edit: nprev - the major paper is "PHYSICAL AND THERMODYNAMICAL EVIDENCE FOR LIQUID WATER ON MARS?" - abstract (which is a paper in itself) is http://www.lpi.usra.edu/meetings/lpsc2009/pdf/1440.pdf (and was linked above ;p ) coming at LPSC 2009.
http://www.marsdaily.com/reports/The_Salty_Tears_Of_Phoenix_Show_Liquid_Water_On_Mars_999.html
So it was water on the landing legs................
Greg
Thanks for the link!
The article reminded me of the atomic force microscope as well. Have there been any summaries published yet concerning the AFM's findings & performance? What little I've seen to date has been fascinating, but haven't seen any definitive science results from it yet. (Been assuming that the AFM was primarily intended as a tech demo, anyhow.)
Dear friends,
I'm sorry if my question comes off-topic, but I don't know about a better place to ask. My question is - are there any copyright issues if I decide to use graphics and charts publishes on the website of NASA in my own scientific articles in a peer-reviewed journal?
Thank you in advance...
Thank you for your long answer!
I won't publish an article if there are problems of this type. I don't like taking risks. Anyway, I never intended to claim that I made a discovery they actually made (for example, perchlorates)... I intended to make my own conclusions that are unique. I will wait, as you suggested.
I am aware that some agencies allow using their data for scientific research. For example:
http://wms.selene.jaxa.jp/selene_viewer/terms_of_use_e.html
... but obviously you have to contact the agency and claim the following: "This research made use of the lunar orbiter SELENE (KAGUYA) data of JAXA/SELENE.”
So you have my promise - I won't publish any data for the moment.
The traditional Science issue presenting preliminary results from Phoenix will be out tomorrow Friday 3 July.
http://www.sciencemag.org/content/vol325/issue5936/index.dtl
http://www.sciencemag.org/content/vol325/issue5936/cover.dtl
http://www.sciencedaily.com/releases/2009/07/090702140841.htm
http://www.nasa.gov/mission_pages/phoenix/images/phx-17067.html
Some nice new images from these papers on the Phoenix image gallery site, especially panoramas of the trench area.
Phil
Has anyone read the Phoenix papers published by Peter Smith et al. - in this current issue of Science?
The Abstract: "H2O at the Phoenix Landing Site - The Phoenix mission investigated patterned ground and weather in the northern arctic region of Mars for 5 months starting 25 May 2008 (solar longitude between 76.5° and 148°). A shallow ice table was uncovered by the robotic arm in the center and edge of a nearby polygon at depths of 5 to 18 centimeters. In late summer, snowfall and frost blanketed the surface at night; H2O ice and vapor constantly interacted with the soil. The soil was alkaline (pH = 7.7) and contained CaCO3, aqueous minerals, and salts up to several weight percent in the indurated surface soil. Their formation likely required the presence of water".
Snowfall blanketed the surface at night!!!?
There's a nonsensational well written article in The Arizona Republic that's worth a quick read on where the Phoenix team are up to - http://www.azcentral.com/arizonarepublic/news/articles/2009/07/03/20090703marsfinding0703.html#comments "One lingering question Smith hopes to solve with more study of the data is whether carbon-based organic molecules, the chemical building blocks of life, are present in the soil". But the mission is out of money and they will have to get grants to do this. Very worth keeping an eye on.
I've just seen that NASA have published a good summary at http://www.jpl.nasa.gov/news/news.cfm?release=2009-106
It opens with "Favorable chemistry and episodes with thin films of liquid water during ongoing, long-term climate cycles may sometimes make the area where NASA's Phoenix Mars mission landed last year a favorable environment for microbes".
I thought the following was particularly interesting "snow (was detected) falling from clouds...............(they reported that) further into winter than Phoenix operated, this precipitation would result in a seasonal buildup of water ice on and in the ground". Not just virga!
I reckon that Phoenix was a second hand mission that produced first class results!
I haven't got to the Science articles but this was an informative popular media article from CBC (Candian Broadcasting Corporation) http://www.cbc.ca/technology/story/2009/07/03/tech-snow-mars-whiteway-clouds.html
'A few times, around 5 a.m., streaks indicating precipitation appeared in the signals. In one case, the snow fell to the lowest level detectable by the instrument — about 50 metres above the surface.......would have continued to descend through the saturated air to reach the surface.........."It would look like frost," he* said.' *Jim Whiteway from York Uni, team leader.
To me, this is an amazing discovery. I start thinking about when the obliquity of Mars was different....thinking and thinking!!!!!!!!
A few more results from Phoenix in tomorrow "Science":
http://www.sciencemag.org/cgi/content/summary/329/5997/1267
http://www.sciencemag.org/cgi/content/abstract/329/5997/1334
And for those of us in the hoi polloi without Science subscriptions, the http://www.jpl.nasa.gov/news/news.cfm?release=2010-294&rn=news.xml&rst=2731.
Slightly off topic here, but I was looking through the Analyst's Notebook for Phoenix on PDS... I'm sure there used to be a section giving the names of rocks etc. with a reference image. I was trying to assemble a map of the site with all the named rocks etc. I'm not talking about the rocks right in the sample field, but out beyond that. Now I can't find that section. Does anyone know if there is any information out there that I'm missing?
Phil
OK folks, answering my own question here...
The names can be found in the Sol Summaries area of the Analyst's Notebook. Select any sol to get started, then in the Report window, choose 'Features and Targets'. You get a list of feature names which links to identifying pictures and other information. It just needs to be combined with a panorama to make a map with placenames. It's a future goal of mine, it won't be done soon. (but feel free to do it for me!)
Try, for instance, the rock Midgard and the polygon trough Land of Oz. They are clear enough, some others are not.
Phil
Following up on my earlier posts, just above... I have collected as many names as I could from the Phoenix Analyst's Notebook, and plotted them on a reprojected panorama, in approximate map geometry. This is a working document, not a finished map, so it's a bit rough, but it's a start. Most of these names will be new to most people. Named features in the RAC work area are well known, but the more distant ones are not. Sadly, the Notebook materials are not very well presented - some features are not labelled, some are actually off the edge of the index image.
Phil
Following up on an older post... this is the Phoenix landing site. A few additional placenames compared with the last post. The spacecraft is shown to scale - the camera locations caused the deck and arrays to hide a much larger area of the surface than the spacecraft itself. Features are controlled by warping the panorama to fit a high resolution DEM.
Phil
Another Phoenix product. A mission isn't over just because it's over. This is a mosaic showing all the RAC images I can find of the area under the lander. There are other images out in the trenching workspace which are not included.
My intention is to combine the SSI mosaic and this mosaic in a 'maximum coverage' mosaic of the lander vicinity. This RAC mosaic includes hideous distortions produced by trying to mosaic images taken close to the surface from many different viewpoints. I have combined numerous images to minimize the areas obscured by various struts and lander components, so little sections of a strut appear here and there where they could not be removed.
Phil
Holy Cow!
Great work Phil.
The names are all so fun! What a great piece of work, Phil. Do you ever sleep?
Sleep? But something might happen in the Solar System!
Phil
And... here's a map projected version of the RAC mosaic, plus the maximum coverage by SSI images, showing the positions of the ice features relative to the workspace at the top right. The SSI mosaic is made from frames taken before anything was touched.
Phil
That is a fabulous image, Phil! It provides wonderful context for the local terrain features.
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