Mars gullies likely not formed by liquid water

July 29, 2016
Martian gullies as seen in the top image from HiRISE on NASA's Mars Reconnaissance Orbiter resemble gullies on Earth that are carved by liquid water. Credit: NASA/JPL-Caltech/UA/JHUAPL

New findings using data from NASA's Mars Reconnaissance Orbiter show that gullies on modern Mars are likely not being formed by flowing liquid water. This new evidence will allow researchers to further narrow theories about how Martian gullies form, and reveal more details about Mars' recent geologic processes.

Scientists use the term "gully" for features on Mars that share three characteristics in their shape: an alcove at the top, a channel, and an apron of deposited material at the bottom. Gullies are distinct from another type of feature on Martian slopes, streaks called "recurring slope lineae," or RSL, which are distinguished by seasonal darkening and fading, rather than characteristics of how the ground is shaped. Water in the form of hydrated salt has been identified at RSL sites. The new study focuses on gullies and their formation process by adding composition information to previously acquired imaging.

Researchers from the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, examined high-resolution compositional data from more than 100 gully sites throughout Mars. These data, collected by the orbiter's Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), were then correlated with images from the same spacecraft's High Resolution Imaging Science Experiment (HiRISE) camera and Context Camera (CTX).

The findings showed no mineralogical evidence for abundant liquid water or its by-products, thus pointing to mechanisms other than the flow of water—such as the freeze and thaw of carbon dioxide frost—as being the major drivers of recent gully evolution.

Gullies are a widespread and common feature on the Martian surface, mostly occurring between 30 and 50 degrees latitude in both the northern and southern hemispheres, generally on slopes that face toward the poles. On Earth, similar gullies are formed by flowing liquid water; however, under current conditions, liquid water is transient on the surface of Mars, and may occur only as small amounts of brine even at RSL streaks. The lack of sufficient water to carve gullies has resulted in a variety of theories for the gullies' creation, including different mechanisms involving evaporation of water and carbon dioxide frost.

"The HiRISE team and others had shown there was seasonal activity in gullies—primarily in the southern hemisphere—over the past couple of years, and carbon dioxide frost is the main mechanism they suspected of causing it. However, other researchers favored liquid water as the main mechanism," said Jorge Núñez of APL, the lead author of the paper. "What HiRISE and other imagers were not able to determine on their own was the composition of the material in gullies, because they are optical cameras. To bring another important piece in to help solve the puzzle, we used CRISM, an imaging spectrometer, to look at what kinds of minerals were present in the gullies and see if they could shed light on the main mechanism responsible."

Núñez and his colleagues took advantage of a new CRISM data product called Map-projected Targeted Reduced Data Records. It allowed them to more easily perform their analyses and then correlate the findings with HiRISE imagery.

"On Earth and on Mars, we know that the presence of phyllosilicates—clays—or other hydrated minerals indicates formation in liquid water," Núñez said. "In our study, we found no evidence for clays or other hydrated minerals in most of the gullies we studied, and when we did see them, they were erosional debris from ancient rocks, exposed and transported downslope, rather than altered in more recent flowing water. These gullies are carving into the terrain and exposing clays that likely formed billions of years ago when liquid water was more stable on the Martian surface."

Other researchers have created computer models that show how sublimation of seasonal carbon dioxide frost can create gullies similar to those observed on Mars, and how their shape can mimic the types of that would create. The new study adds support to those models.

The findings were published in Geophysical Research Letters.

Explore further: Image: Frosty gullies on the northern plains of Mars

More information: J. I. Núñez et al. New insights into gully formation on Mars: Constraints from composition as seen by MRO/CRISM, Geophysical Research Letters (2016). DOI: 10.1002/2016GL068956

Related Stories

Image: Frosty gullies on the northern plains of Mars

July 31, 2015

Seasonal frost commonly forms at middle and high latitudes on Mars, much like winter snow on Earth. However, on Mars most frost is carbon dioxide (dry ice) rather than water ice. This frost appears to cause surface activity, ...

Mars gullies likely contain 'no water', study says

December 21, 2015

Months after scientists announced "the strongest evidence yet" of liquid water on Mars, a study Monday said there was none at least in the valleys carved into numerous Red Planet slopes.

NASA orbiter finds new gully channel on Mars

March 20, 2014

A comparison of images taken by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter in November 2010 and May 2013 reveal the formation of a new gully channel on a crater-wall ...

Are gas-formed gullies the norm on Mars?

December 6, 2011

In June 2000, Martian imaging scientists made a striking discovery — data from NASA’s Mars Global Surveyor spacecraft found gullies on the red planet. Gullies on Earth form when water runs down steep slopes and ...

Recommended for you

How massive can neutron stars be?

January 16, 2018

Astrophysicists at Goethe University Frankfurt set a new limit for the maximum mass of neutron stars: They cannot exceed 2.16 solar masses.

Black hole spin cranks-up radio volume

January 12, 2018

Statistical analysis of supermassive black holes suggests that the spin of the black hole may play a role in the generation of powerful high-speed jets blasting radio waves and other radiation across the universe.

28 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

wduckss
2 / 5 (8) Jul 29, 2016
A little refreshment inside the single-mindedness.
Always remember that should look at the evidence and ignore the hypothesis. Mars is dry as a bone. The young body is not created by molten core, no significant geological processes ... everything is in its infancy (in early stage).
But the believers jelly that, is the same as on Earth (as in heaven, so on Earth).
I welcome the first the messengers.

http://www.unexpl...niverse/
BongThePuffin
Jul 29, 2016
This comment has been removed by a moderator.
Mordechai Mineakoitzen
2.6 / 5 (5) Jul 29, 2016
Mars and evidence of water.

Iceberg tracks...
http://www.space....ars.html

Pack ice, I don't know why this one here doesn't get more attention, it's amazing, and look at the smooth floors of those craters.
http://www.esa.in...ozen_sea
BackBurner
2.2 / 5 (5) Jul 29, 2016
"The findings showed no mineralogical evidence for abundant liquid water or its by-products, thus pointing to mechanisms other than the flow of water—such as the freeze and thaw of carbon dioxide frost—as being the major drivers of recent gully evolution."

This represent a level of ignorance that certainly should be considered unacceptable in a person writing for a science blog.

Carbon dioxide "frost" doesn't "thaw" into a liquid capable of forming gullies. CO2 sublimes directly to a gas. The hypothesis is absurd.
wduckss
2.3 / 5 (3) Jul 30, 2016
@backburner
Your objection is correct, but in the same way you need to react to the allegations of water (reminiscent of watching in coffee grounds).
The processes of formation of complex substances suggest that on Mars must be water, it is not disputable. Disputable is the amount of water.
It is not acceptable that without any evidence "science" claims (100%) that there are oceans, rivers ... They think they we are blind or that we can see their hallucinations.
Kedas
5 / 5 (3) Jul 30, 2016
one explanation does not exclude the other, Mars is big place.
jonesdave
3.7 / 5 (9) Jul 30, 2016
I think people need to read the paper carefully (not to mention the above article). They are not saying that water hasn't flowed recently on Mars; merely that these gullies are likely not caused by H2O. The lineae mentioned in the article are thought to be from highly saline water. As even the article says, "Gullies are distinct from another type of feature on Martian slopes, streaks called "recurring slope lineae,"...............Water in the form of hydrated salt has been identified at RSL sites."
jonesdave
3.5 / 5 (8) Jul 30, 2016
Carbon dioxide "frost" doesn't "thaw" into a liquid capable of forming gullies. CO2 sublimes directly to a gas. The hypothesis is absurd.


Nobody has said these gullies are caused by liquid CO2. Not sure where you got that idea from. To quote from the paper: "These observations indicate a limited role for long-lived liquid water in the formation and modification of martian gullies, and support a stronger role for **CO2 frost-related** processes." My emphasis.
However, liquid CO2 has been hypothesised as being a possible mechanism by other authors. See, for instance:
Liquid CO2 breakout and the formation of recent small gullies on Mars.
Musselwhite, D.L., et al.
http://onlinelibr...496/full
wduckss
2 / 5 (4) Jul 30, 2016
"Until the first successful Mars flyby in 1965 by Mariner 4, many speculated about the presence of liquid water on the planet's surface. This was based on observed periodic variations in light and dark patches, particularly in the polar latitudes, which appeared to be seas and continents; long, dark striations were interpreted by some as irrigation channels for liquid water. "Wikipedia
50 years of research to obtain a confirmation of the existence of water, but not an inch (or one evidence) closer, all we are further and further.
Until when and how much should the time that we say we go how collected evidence speaks.
jonesdave
3.8 / 5 (10) Jul 30, 2016

50 years of research to obtain a confirmation of the existence of water, but not an inch (or one evidence) closer, all we are further and further.
Until when and how much should the time that we say we go how collected evidence speaks.


Not sure what you mean. The evidence of hydrated salts (perchlorates) in the recurring slope lineae is pretty convincing evidence that water (albeit very salty) flows on Mars periodically.

http://www.nasa.g...y-s-mars
rossim22
1.8 / 5 (9) Jul 30, 2016
This is incredible evidence for supporters of the "electric universe", or simply that large electrical interactions between celestial bodies carved some of the geography of our fellow planets and moons. The gullies are clearly dendritic and emanating from the nearby crater.

"Martian gullies... resemble gullies on Earth that are carved by liquid water. Credit: NASA/JPL-Caltech"

This caption perfectly illustrates the researchers' bias evident in the deduction of watery processes involved throughout the solar system, often without water byproducts or with the presence of minerals which would not exist near water (e.g., olivine). Once electrical mechanisms are investigated they can also be applied to presumed lava tubes, canyons, mounds w/ central craters, and active jets ubiquitous in our Solar System.

Liquids do flow and provide alterations to geography, though discharges with passing comets, moons, planets, and other phenomena should be another potential tool in the box.
wduckss
1.7 / 5 (6) Jul 31, 2016
@jonesdave
".. On Mars must be water, it is not disputable. Disputable is the amount of water." from my comments.
There is no doubt that there is water in trace (on all bodies), the problem begins when of, mouse create a herd of elephants.
@rossim22
Always should distinguish between stories and hypotheses of evidence. It can not  talk about water on the bodies which are constantly frozen, where maximum temperatures are below zero (C). The first elements emerging substances are H2 (~ 80-89%), then the resulting He (up 11%), oxygen, carbon and nitrogen, which exist outside the of traces on "cold" bodies, everything else is in trace of traces. Type and dynamics of geological processes, brings, and some exceptions.
torbjorn_b_g_larsson
4.3 / 5 (7) Jul 31, 2016
Geology advances.

The crackpots however does not:

@rossim: "This is incredible evidence for supporters of the "electric universe"".

Yes, but such 'evidence' is not evidence for anyone else, and isn't establishing a fact such as the science related here did - which incidentally rejects your non-quantified 'evidence'. Peer review publishing, or it doesn't exist as evidence.

@wduckss: Who is creating expectations of vast volumes of water? On the other hand we can't make up expectations for minimal volumes of water either. There is a potential for subsurface water reservoirs, but the current evidence doesn't support or reject. (It makes it less likely, but that isn't saying much as of yet.

wduckss
1.8 / 5 (5) Jul 31, 2016
@torbjorn_b_g_larsson
"There is a potential for subsurface water reservoirs, but the current evidence does not support or reject."

50 years for search is really enough time (no one pool, already 1 liter).
Enough is generations lived with this story. Underwater water always give evidence of its existence, this is not the case.
Reality must not prejudice, it just speeds up the the progress. While living with the old a failed stories we do not go forward. Today we have the same story as 50 years  from letter to letter (without evidence and progress).
I'm interested  only discoveries, not atikviteti and old storys.
jonesdave
3.3 / 5 (7) Jul 31, 2016
This is incredible evidence for supporters of the "electric universe", or simply that large electrical........


Snipped usual nonsense.

How can the finding that CO2 frost has carved some RECENT gullies, be "incredible evidence" for the scientifically illiterate claims of EU? Please explain. How does CO2 frost carving gullies equate to proof that all sorts of unquantified electric woo (never ever seen, nor quantified, nor even written up) actually occurred? There is ample evidence of subsurface ice on Mars. There is evidence that liquid water periodically flows today. In a warmer past it would have been liquid at the surface.

Please provide a link to something vaguely scientifically literate that explains this electric woo hypothesis of Mars canyons, gullies etc. Without it you have precisely what you had before; i.e. zilch.
rossim22
1.6 / 5 (7) Jul 31, 2016


The crackpots however does not:

@rossim: "This is incredible evidence for supporters of the "electric universe"".

Yes, but such 'evidence' is not evidence for anyone else, and isn't establishing a fact such as the science related here did - which incidentally rejects your non-quantified 'evidence'. Peer review publishing, or it doesn't exist as evidence.


@torbjorn: If there is a tiny possibility that one previously "rejected" idea could provide the source of these gullies, bulls-eye craters, craters on crater rims, mounds with central craters, active jets, and several other current anomalies... then shouldn't it be investigated with a bit more scrutiny than in the past?

Your argument contains several fallacies, specifically an appeal to authority and appeal to tradition. Researchers' bias and confirmational bias have plagued science in the past, there's no doubt that it occurs today and in the future, even if done so innocently.

https://youtu.be/JF-ypC3jsHI
jonesdave
3.5 / 5 (8) Jul 31, 2016

Liquids do flow and provide alterations to geography, though discharges with passing comets, moons, planets, and other phenomena should be another potential tool in the box.


There was a recent close encounter between comet Siding Spring and Mars. Perhaps you could outline the gullies and canyons that were carved due to this encounter. Moons and planets, in case you haven't noticed, do not go wandering around buzzing Mars on a regular basis.
jonesdave
3.3 / 5 (7) Jul 31, 2016
. .....Researchers' bias and confirmational bias have plagued science in the past, there's no doubt that it occurs today and in the future, even if done so innocently.

https://youtu.be/JF-ypC3jsHI


Yep, pseudoscience 101. Bias, conspiracy, and a youtube link. Classic.
jonesdave
3.3 / 5 (7) Jul 31, 2016
@torbjorn: If there is a tiny possibility that one previously "rejected" idea could provide the source of these gullies


How can science reject an "idea" that doesn't exist within the scientific realm? If it has been written up in a decent peer reviewed journal, please link to it. If not, why hasn't it?

tl;dr? you cannot reject something that doesn't exist.
rossim22
2 / 5 (4) Jul 31, 2016
@torbjorn: If there is a tiny possibility that one previously "rejected" idea could provide the source of these gullies


How can science reject an "idea" that doesn't exist within the scientific realm? If it has been written up in a decent peer reviewed journal, please link to it. If not, why hasn't it?

tl;dr? you cannot reject something that doesn't exist.


Please google "appeal to authority" and "appeal to tradition". Also, present researchers will build upon what's already accepted in order to attain telescope time and a career, not necessarily build upon what's correct.
Maggnus
4.2 / 5 (5) Aug 01, 2016
@torbjorn: If there is a tiny possibility that one previously "rejected" idea could provide the source of these gullies


How can science reject an "idea" that doesn't exist within the scientific realm? If it has been written up in a decent peer reviewed journal, please link to it. If not, why hasn't it?

tl;dr? you cannot reject something that doesn't exist.


Please google "appeal to authority" and "appeal to tradition". Also, present researchers will build upon what's already accepted in order to attain telescope time and a career, not necessarily build upon what's correct.

Cause itsa CONSPIRATORY!!!!

If you don't understand the question, don't try to compound your mistake by
jonesdave
3 / 5 (6) Aug 01, 2016

Please google "appeal to authority" and "appeal to tradition". Also, present researchers will build upon what's already accepted in order to attain telescope time and a career, not necessarily build upon what's correct.


So what is correct? Somebody, at some time, must have written this rubbish down, yes? They must have explained and quantified the mechanism, yes? So what is causing electric woo to create gullies, canyons and craters on Mars? And don't say EDM!!! No electrical engineer I have dealt with can conceive of a way for this to happen "in the wild", as it were. If you know any differently, then please point us to the research.
Otherwise, as I've said, you don't have an hypothesis to reject.

[cont...]
jonesdave
3 / 5 (6) Aug 01, 2016
[cont....]
No, you cannot just rock up and get telescope or laboratory time. You need to make an application, where you lay out the basis of the research you'd like to perform. So, where has this happened? I would assume the the people making the application were suitably qualified in a relevant field, such as planetary science, astrophysics, etc. Where has this occurred? If it came from EU followers, then I very much doubt there is anyone within that motley bunch with such qualifications.
I'm afraid it is just more scientifically illiterate, mythology based woo from the idiots T & T. Have a close look at how their 'electric comet' nonsense is getting along, if you want an example of why nobody would let them near a telescope or lab.
[cont....]
jonesdave
3 / 5 (6) Aug 01, 2016
[cont....]
I refer, of course, to the fact that their 'hypotheses', for want of a better word, have continually been shown to be utter nonsense, and scientifically worthless. Take Thornhill's lie about an 'electric flash' at Tempel 1. Does he not understand electric discharges? And the signature they would leave at certain wavelengths? Such as x-ray? So why is his lie still on the pages of a crank science website, when he's had a decade to check the results from Chandra and SWIFT, that showed him to be wrong? Why do so many EU acolytes still believe that rubbish, when they can check the same evidence?
And his assertion, in 2006, that what scientists were seeing at comets wasn't H2O, but OH? Did he not understand that the v3 asymmetric stretch cannot possibly occur in an OH molecule? And that that is what was seen by the KAO in 1986? Etc, etc, etc.

Telescope time? Wouldn't give them the controls to my TV!
torbjorn_b_g_larsson
4.2 / 5 (5) Aug 01, 2016
@torbjorn_b_g_larsson
"There is a potential for subsurface water reservoirs, but the current evidence does not support or reject."

50 years for search is really enough time


We haven't drilled down below the crust.

The consensus model is an ice cap, which could have either thin surface liquid films or larger amounts of water below.

Either of those would be of astrobiology interest.

Besides that, there is at least one system of RSL which has been claimed to be potentially supplied by aquifers, as well as evidence for ancient such. (Say, the hydrothermal vent that trapped Spirit.)
torbjorn_b_g_larsson
4.2 / 5 (5) Aug 01, 2016
@torbjorn: If there is a tiny possibility that one previously "rejected" idea could


But it can't, as we can see from its rejection and/or its continued failure to provide any quantified explanation for anything at all.

Your argument contains several fallacies, specifically an appeal to authority


You don't get science - it *is* authority. Earned by hard work that, say, EU proponents never do, and by the sucess of its usage that, say, EU proponents never will see.
Captain Stumpy
3 / 5 (2) Aug 06, 2016
Your argument contains several fallacies, specifically an appeal to authority and appeal to tradition
@rossim
uhm -considering your lack of evidence and the only link you've used is youtube... we can emphatically state that you've not made an argument at all, just offered opinion and pseudoscience

you can't make any argument based upon no evidence, like you're doing

case in point:
you argue that the past is rife with "bias", but provide no empirical evidence... and even with evidence, the past was also predominantly controlled by religion until recently

so you're comparing apples to Duct tape and assuming that, because both can be purchased at a typical super-center wally-world, then they both can be used for the same purpose

these might help you
http://www.auburn...ion.html

https://en.wikipe...c_method

https://en.wikipe...evidence
LifeBasedLogic
Aug 08, 2016
This comment has been removed by a moderator.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.