Mars Spiky Probe

Quote from the Phoenix website:
"...Spiky Probe on NASA Mars Lander Raises Vapor Quandary
09.04.08. -- A fork-like conductivity probe has sensed humidity rising and falling beside Phoenix, but when stuck into the ground, its measurements so far indicate soil that is thoroughly and perplexingly dry..."

While thinking at this instrument on the arm of the Lander, I thought to carry out a simple test: will my tap water conduct electricity?
Yes of course! It's also dangerous in some cases when using electric appliances in the bathroom!!!
BUT... will it present the same propriety (conduct electricity) once frozen as ice... as on mars?
Well, I took my multimeter, opened my refrigerator and put the test leads on the ice directly.
Well with much of my surprise, it presented an OPEN CIRCUIT!!!
So I wonder:
What the he*k this experiment on mars for?
:shock: :roll: :lol:

Hi Mario59

Sounds like real science at work. But, is'nt it just too easy? Should'nt they have thought of doing the same experiment immediately the results came in? What about their references to Earth's arctic deserts where presumably prototypes of the instrument would have been tested? Something seems to be missing somewhere!!

But high powered scientists have been known to goof up before.


The experiment was designed to establish whether there were any boundary films of mobile H20 on grain and ice surfaces as there are in Earth's permafrost regions.

The experiment proved beyond doubt that there are no measurable, mobile H20 molecules in the regolith. The measurement capability and tolerences of the probe would be an order of magnitude better than a multimeter - they are looking for trace molecules.

Hi Brian

Having thought it over, I was just going to make the same point you made above but you beat me to it.



Forgot to mention above that I thank you for educating me as I did'nt know or forgot that Ice was such a good insulator and mistakenly thought that it would conduct electricity. Your experiment crystallized my thinking on this.


Ciao LWS and Brian!

I thanks you for the "real science at work".
It's still too magniloquent for my little experiment.
LWS, you say: "...But, is'nt it just too easy?..."
Yes!, way easy. The very same minding blanked me for a while once I first thought at it and before writing in this forum.
All this, let me remember in my childhood; at the elementary school, when one day, the teacher, explained all us how the eclipse works.
She carried two oranges, (one bigger, one smaller, both held by a little wire) and a candle.
Using these simple elements she explained us why that day we would have the sun ecplipse.
I was SO SURPRISED I understood so easily the "working" of that wonderful celestial phenomena!
Planets, oranges, a candle. What they have to do each other?
So, what I can say?
Too easy? Yes, maybe.
But the question is: If you have a one-way mission, single shot; would you load something unuseful aboard?
Don't forget that the lander has also a microphone aboard and seems there's no software to manage it...
A spin-off project?

Yes, maybe.
Maybe also is the result of some overwhelmed engineers working group, with the aim of CATCHING RESULTS, rather than thinking well enough before "doing"...

ciao and thanks to all for the kind attention :D


Vapor to solid and the reverse process.
The source of acidity on Mars in bulk when loss of hydrogen is happening? An action perhaps occurring only in vapor phase, as an indirect item from the results?

Perhaps also the sublimation process is very tied to the ambient atmosphere/surface charge differential, making a stable vapor state beyond other expected constraints?
I remember viewing some of the ice cap margin photos and seeing a clear erosion/ smoothing of the soil shaping below thin transparent ice sheeting ONLY on the sunlit side. The action of erosion is ongoing where-ever the excitation is active, even under the ice, shaded areas remained sharp edged, rough and steep walled, with both aspects under long term ice cover on Mars polar ice cap margin. Would the erosive actions be performed by a vapor transition state under ice cover, with the charged state of the vapor isolated from the atmospheric charged state? Normally the vapors would mix and under the ice insulator, the soil would be the interacting partner for the vapors, entirely the opposite of the experiments results. A supersaturated water vapor state, confined by an icy capped insulating layer. I'm sure in many instances the CO2 would predominate, as we see at the 'spiders'.
I have also read that large single ice crystals once formed in blocks of ice, will be the first areas of water phase transition to liquid, and presumably to vapor state, when the ice block approaches the transition conditions. This would indicate that pockets of vapor would form internally in the ice block routinely in zones shaped by the crystals core. I have seen this in images. I'll try to find a link. High energy transitioning may be giving a pH difference in the ice layers and main ice caps where the isolated pockets of change are occurring.
I'm sure someone should try to correct some of my thinking about the extension of the concept from the reported 'humidity' readings.

Dana, in some the images using the microscope imager some of the particles look like particles of clay.
Clay is very absorbent of water. If clay on the surface immediately absorbed liquid water would that affect the TECP readings?

Bob Clark