Liquid water (brine) detections on Mars a data processing artifact

There is a new paper published by scientists analyzing Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) data from Mars Reconnaissance Orbiter (MRO).

agupubs.onlinelibrary.wiley.com...

And it looks like they've found that a filtering step during data conversion can cause artifacts looking like perchlorate (brine).

... we were unable to confirm any of the published orbital perchlorate detections.

It kinda sucks. On the other side it is great to see the scrutiny applied to the data.

a reply to: moebius
Thanks for the heads-up, this is a worrying development if their findings are valid. I shared the link to the paper to the Unmanned Spaceflight Forum, where there are many knowlegeable people and even members of mission control.

Wow, they were finding a lot of perchlorates on Mars. It was like the new buzz word almost. All kinds of papers built around it. Papers about perchlorates and Viking lander results. Papers about rover data and perchlorates. Didn't the polar lander confirm perchlorates too?

I am glad if they were wrong. Perchlorates are not brine as most would think of it. Its not sodium chloride and water. Unless I am mistaken it is more toxic than that and only extremophiles can live in it. From all the perchlorate talk I was starting to look at Mars as a poison planet.

I can envision much better environments that have clean fresh water, under ground in lakes and caves, like in the antarctic. All you would need is an underground heat source and life would find a way.

An old tune, but if they had a SEM along with that Spectrometer, there would be no controversy.

a reply to: charlyv

If you can fly a microscope for the rock geeks (polar lander) then you can fly one for the life geeks. I read something like that just today.

Even though the OP is talking about MRO and a SEM would not do a lot of good in orbit

originally posted by: LookingAtMars
a reply to: charlyv

If you can fly a microscope for the rock geeks (polar lander) then you can fly one for the life geeks. I read something like that just today.

Yep, and a huge mystery why they would not have that pair always together. Like why have one that can only handle half the cases. Like carrying a toolbox with only a straight slot screwdriver.

That's only a relative small number of pixels compared to the rest of the images. Spectrography works by taking the wavelengths of emitted light, identifying the emission spectra of particular elements and comparing those against known chemicals and elements. Their problem was that when they hit the pixels on the edge of a crater, the sunlight side would get averaged with the shadow zone and give an average value, which would match the expected spectra for perchlorates.

en.wikipedia.org...

"In November 2018, it was announced that CRISM had fabricated some additional pixels representing the minerals alunite, kieserite, serpentine and perchlorate.[6][7][8] The instrument team found that some false positives were caused by a filtering step when the detector switches from a high luminosity area to shadows.[6] Reportedly, 0.05% of the pixels were indicating perchlorate, now known to be a false high estimate by this instrument.[6] However, both the Phoenix lander and the Curiosity rover[9] measured 0.5% perchlorates in the soil, suggesting a global distribution of these salts.[10] Perchlorate is of interest to astrobiologists, as it sequesters water molecules from the atmosphere and reduces its freezing point, potentially creating thin films of watery brine that —although toxic to most Earth life— it could potentially offer habitats for native Martian microbes in the shallow subsurface.[6][8] (See: Life on Mars#Perchlorates)"

a reply to: moebius

Over the years I've read of a number of accounts where scientists think they have found water on the moon, mars or somewhere elese.

I always ask myself; why do they think its water?

Are they merely hoping its water? Are they doing this just and gee up public positivity about paying for space adventures by the tax payers for the beenfits of the big mutli national corporations.

I sometimes ask my self how can these scientists be certain its water and not some liquid that is high acidic acid of some sort?

If they have had actual probes inserted into the liquid to test it then fair enough but to simply see a substance that resembles water from several ks up in the air and say it might be water, tells me they are being somewhat rash in their claims its water.

Scientists are generally a very conservative lot not preach that we should not claim something is something unless there is verifiable evidence of it being so.

originally posted by: Azureblue
a reply to: moebius

Over the years I've read of a number of accounts where scientists think they have found water on the moon, mars or somewhere elese.

I always ask myself; why do they think its water?

Are they merely hoping its water? Are they doing this just and gee up public positivity about paying for space adventures by the tax payers for the beenfits of the big mutli national corporations.

I sometimes ask my self how can these scientists be certain its water and not some liquid that is high acidic acid of some sort?

If they have had actual probes inserted into the liquid to test it then fair enough but to simply see a substance that resembles water from several ks up in the air and say it might be water, tells me they are being somewhat rash in their claims its water.

Scientists are generally a very conservative lot not preach that we should not claim something is something unless there is verifiable evidence of it being so.

Water is the universal solvent. It will dissolve just about anything. That provides mobility for atoms, ions, molecules and chemicals to move around it. It absorbs a tremendous amount of heat energy before it will evaporate. Plus it is made up from a couple of simple atoms; oxygen and hydrogen which are formed from stellar processes. If you get liquid water, then there must be air pressure, heat, and the possibility of amino acids.

originally posted by: wildespace
a reply to: moebius
Thanks for the heads-up, this is a worrying development if their findings are valid. I shared the link to the paper to the Unmanned Spaceflight Forum, where there are many knowlegeable people and even members of mission control.

Seems to be "crickets" over there at UMSF. Either they are distracted by the InSight landing or NASA hasn't told them what to say yet

originally posted by: LookingAtMars
Wow, they were finding a lot of perchlorates on Mars. It was like the new buzz word almost. All kinds of papers built around it. Papers about perchlorates and Viking lander results. Papers about rover data and perchlorates. Didn't the polar lander confirm perchlorates too?

I am glad if they were wrong. Perchlorates are not brine as most would think of it. Its not sodium chloride and water. Unless I am mistaken it is more toxic than that and only extremophiles can live in it. From all the perchlorate talk I was starting to look at Mars as a poison planet.

I can envision much better environments that have clean fresh water, under ground in lakes and caves, like in the antarctic. All you would need is an underground heat source and life would find a way.

Scientists think there could be life on one of Saturn's moons in rivers that flow deep below the surface. I would assume that water is heated from the core of the planet.

a reply to: LSU2018

Yea, Saturn's gravity plays a role in the heat. There are a few moons of Saturn and Jupiter that look promising.

Mars is so much closer though, but not as easy to come up with a heat source. The scientists would have to be wrong about Mars' core being dead and maybe there is some magma left deep under ground. Could be natural nuclear fusion going on underground. Maybe something down there making heat. InSight should provide some insight.

a reply to: stormcell


Thanks for the info, that's good but I still cant see what cause they have to pronounce it (may be) water?

Is it because it encourages positivity in the masses about travel to the moon and hence cause them to agree to funding something that only big international corporations will own and operate.

Why are they not as conservative with their announcements in space as they are on planet earth?

originally posted by: Azureblue
a reply to: stormcell


Thanks for the info, that's good but I still cant see what cause they have to pronounce it (may be) water?

Is it because it encourages positivity in the masses about travel to the moon and hence cause them to agree to funding something that only big international corporations will own and operate.

Why are they not as conservative with their announcements in space as they are on planet earth?

They are very conservative, and the only more-or-less definite pronouncement was about underground water detected by a radar.

The rest of it are "maybes" and "possibles".

The OP's title should be changed; perchlorates are not brine, they are chemicals that can form brine if in contact with water.

a reply to: wildespace


"The rest of it are "maybes" and "possibles". - Yes that's right but that's what makes me think their intent is to get us to be more positive about the likelyhood of water and therefore of colonization than is warranted.

If they chose to say 'we are unable to say what it is" then that would be a more honest assessment in my view.

Using "maybes" and "possibles" is IMO, a very subtle way of raising our hopes for space travel and colonization a just a little too more than as scientists, they should be.

It's like they have told the scientists to sell us a dream but within their boundaries as scientists.