LadyAstronomer
Bookworm
Reged: 11/15/07
Posts: 2796
Loc: Library of Congress
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NASA release pertaining to recently published results from MRO and CRISM, one of the scientific instrument packages on MRO.
Diverse, Wet Environments on Ancient Mars
For more CRISM imagery you can visit the CRISM Gallery.
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"I do not know what I may appear to the world, but to myself I seem to have been only a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me." -- Sir Isaac Newton
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ericjacob613
Photon Hog
Reged: 05/25/07
Posts: 2694
Loc: Santa Barbara CA
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So, I have to ask, why did they land in search of water when they could have landed in a dried-up delta and looked for organics?
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 6495
Loc: Beatrice, Nebraska
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Quote:
So, I have to ask, why did they land in search of water when they could have landed in a dried-up delta and looked for organics?
They landed in areas where water was thought to have existed because at least on Earth, water is needed for life. Viking 1 landed in the Chryse basin downstream of where the various outflow channels of Kasei Vallis and Maja Vallis flowed into. Viking 1 looked for organics but didn't find any for some reason. Pathfinder landed almost right in the mouth of Ares Vallis where the signs of extensive and massive flows of water were easily visible in the terrain. Unfortunately, it was only a test project to demonstrate the air-bag method of landing and was only equipped with a device for doing limited element detection (alpha particle X-ray spectrometer), so it could not detect organics. Both MER spacecraft landed in areas where there was thought there might once have been water on or near the surface, but again, their emphasis was to see if there was firm geologic evidence for past water episodes via an analysis of the rocks. They "followed the water" to look for places where it might be worth sending a probe to actually look for signs of past life. It is only now through a detailed planet-wide survey with the newer instruments and landers that we have a better idea of where signs of past life (or even present life) might exist. The 'delta' features noted by the current high-resolution orbiter images are further signs that water flowed, and may make good landing locations for the Mars Science Laboratory, but they by themselves do not indicate that organics will be found there. Clear skies to you.
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ericjacob613
Photon Hog
Reged: 05/25/07
Posts: 2694
Loc: Santa Barbara CA
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Thanks, David! A concise and clear answer to my semi-idiotic question.
Maybe it's just me, but it seems the more we find out about the Red Planet, the more I'm itching to put a person there.
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LadyAstronomer
Bookworm
Reged: 11/15/07
Posts: 2796
Loc: Library of Congress
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Below is a recent release related to the one above. This release is about a paper on Mawrth Vallis phyllosilicates.
A nice CRISM image of phyllosilicates in Mawrth Vallis
Another nice CRISM image. The one is of Pyhllosilcates and Volcanics in Nili Fossae
We will be hearing much more about these minerals and regions on Mars in the future.
Full Press Release Here: MARTIAN CLAYS TELL STORY OF A WET PAST
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"I do not know what I may appear to the world, but to myself I seem to have been only a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me." -- Sir Isaac Newton
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Joad
Wordsmith
Reged: 03/22/05
Posts: 11748
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I've been convinced for a long time that there was a lot of water on Mars. The topographical evidence just seemed overwhelming. Oddly, I am less interested in the question as to whether there was/is life on Mars than the more musical question:
ahem . . .
Where has all the water gone?
Long time passing.
Where has all the water gone?
Long time ago.
Where has all the water gone?
Was it sold to a Klingon?
When will we ever learn?
When will we ever learn?
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rick rian
Seeker of Truth
Reged: 08/03/04
Posts: 12316
Loc: SE Minnesota
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Quote:
I've been convinced for a long time that there was a lot of water on Mars. The topographical evidence just seemed overwhelming. Oddly, I am less interested in the question as to whether there was/is life on Mars than the more musical question:
ahem . . .
Where has all the water gone?
Long time passing.
Where has all the water gone?
Long time ago.
Where has all the water gone?
Was it sold to a Klingon?
When will we ever learn?
When will we ever learn?
Now THAT was deep ... 
and pretty clever too! 
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Rickster
NexStar 8i, TV85, Canon 15x50is
Time is precious, waste it wisely.
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LadyAstronomer
Bookworm
Reged: 11/15/07
Posts: 2796
Loc: Library of Congress
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Yet another masterwork, Sir Joad!! 
Mariner 9 (and Viking) provided us with the imagery that gave us our first solid indication of past Martian water. However, the only thing we actually knew from Mariner 9 was that the geomorphology of some features appeared similar to those formed by the flow of liquid water on Earth. All that could be assumed is that whatever "carved" the Martian features likely had a viscosity similar to that of liquid water. In fact, there is still some debate today regarding certain features having been formed by ice and/or wind instead of liquid water.
The mineralogy is what makes these current findings significant. Specific minerals and rock types, like specific plant species, are found in certain environments that are conducive to their "growth." By studying the lithology, we can determine the history of Mars as a planet.
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"I do not know what I may appear to the world, but to myself I seem to have been only a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me." -- Sir Isaac Newton
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Rick Woods
Post Laureate
Reged: 01/27/05
Posts: 3978
Loc: Inner Solar System
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I recently picked up a book of papers written from MGS results. There's one paper dealing with the possibility of liquid water on present day Mars.
They said there are 5 regions on Mars that have high enough air pressure and temperature to allow liquid water to exist. These 5 regions comprise 29% of the Martian surface (Hellas, Argyre, and 3 northern areas that I can't remember). Conditions consist of air pressure being above the triple point of water (6.1mb), with temperatures above freezing but not high enough to boil the water. Air pressure was up into the teens in these areas.
They didn't say there was water - only that the conditions were there. But, what does this say for the prospects of life?
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- Rick
14" LX200GPS
8" Meade 826C
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llanitedave
Humble Megalomaniac
Reged: 09/26/05
Posts: 9655
Loc: Amargosa Valley, NV, USA
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I think we should also allow for the probability that any liquids that might exist on Mars will be highly concentrated brines. Freezing and evaporation would have somewhat different ranges under those conditions.
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Homebuilt 10" dob, old Coulter mirror.
16" Royce conical mirror: Construction on S.O.E. (Sauron's Other Eye) has officially begun!
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Rick Woods
Post Laureate
Reged: 01/27/05
Posts: 3978
Loc: Inner Solar System
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True enough.
OK, I'll reveal a small part of my massive ignorance: I'm pretty sure a brine would have a lower freezing temperature; what about evaporation temperature? Higher or lower? Would this whole consideration expand or contract the potential life zone conditions?
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- Rick
14" LX200GPS
8" Meade 826C
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llanitedave
Humble Megalomaniac
Reged: 09/26/05
Posts: 9655
Loc: Amargosa Valley, NV, USA
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I feel an experiment coming on...
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Homebuilt 10" dob, old Coulter mirror.
16" Royce conical mirror: Construction on S.O.E. (Sauron's Other Eye) has officially begun!
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RRaubach
AstroCowboy
Reged: 01/26/05
Posts: 2173
Loc: Douglas (Converse County),WY
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A brine would have a lower freezing point than water. Zero degrees Farenheit is the freezing point of a NaCl saturated aqueous solution, or approx -20 degrees Celsius. other salt forms could further depress the freezing point; i.e.: Calcium chloride. Look up: "Molal freezing point constant."
The boiling point is also raised by the addition of an electrolyte to water. It may be calculated using the "Molal boiling point constant" to calculate the elevation. Molal: Moles of solute/Kg of Solvent, not of mass of solution. 
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Rodger
Meade SN-10 (UHTC) on Tak EM-200 mount/Antares rotating rings. Moonlite focuser.
Parallax 14.5" Newtonian on HD 200 mount (arriving soon!) w/ conical Royce mirror.
TMB 203 f/7 APO refractor on Tak NJP-160 mount.
Discovery 12.5" PDHQ
Schneider 18x80 "Flakfernrohr" binoculars/tripod mounted. Canon 15x50 IS binoculars
Unihedron Sky Quality Meter
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Rick Woods
Post Laureate
Reged: 01/27/05
Posts: 3978
Loc: Inner Solar System
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Is the triple point of brine different than that of plain water?
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- Rick
14" LX200GPS
8" Meade 826C
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llanitedave
Humble Megalomaniac
Reged: 09/26/05
Posts: 9655
Loc: Amargosa Valley, NV, USA
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It's not so much a "point" as a "smear". The smear is broader for a brine, but I think it's centered pretty close to the same spot on the graph.
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Homebuilt 10" dob, old Coulter mirror.
16" Royce conical mirror: Construction on S.O.E. (Sauron's Other Eye) has officially begun!
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