15-Million-Year-Old Crater On Earth Reveals Clues About Mars' Watery Past (space.com) 33
A reader shares a report from Space.com: Ries Crater, or Nordlinger Ries, is located in western Bavaria, Germany, and formed roughly 15 million years ago, when a meteorite struck. This site has incredibly well-preserved rocks and minerals that bear similarities to the Martian surface. Therefore, samples from this impact site on Earth may shed light on Mars' past, according to a new study. Today, Mars is too cold to host liquid water on its surface, which is a requirement for life as we know it on Earth. However, 4 billion years ago, Mars may have been warm enough for surface oceans and, possibly, life, according to the study.
The researchers studied rock samples from Ries Crater, which was once a body of water. Their findings show that the samples have a high pH based on the ratio of nitrogen isotopes, as well as a high alkalinity, which indicates an imbalanced pH level, according to the study. NASA's Mars 2020 rover is planned to land in a similar, well-preserved ancient crater that is believed to have also contained liquid water in its past. The findings suggest that the Martian crater will have a chemical composition comparable to that of Ries Crater. Therefore, studying the alkalinity, pH and nitrogen content of samples from the Ries Crater could help the researchers better understand the properties of ancient water on Mars and, in turn, determine the amount of carbon dioxide that was in the planet's atmosphere billions of years ago. Although complex life is unlikely, simpler microorganisms could have survived if water on Mars had a neutral pH level and was highly alkaline, the researchers said in the statement. These conditions would indicate that the atmosphere had enough carbon dioxide to warm the planet and make liquid water possible, the scientists added.
The researchers studied rock samples from Ries Crater, which was once a body of water. Their findings show that the samples have a high pH based on the ratio of nitrogen isotopes, as well as a high alkalinity, which indicates an imbalanced pH level, according to the study. NASA's Mars 2020 rover is planned to land in a similar, well-preserved ancient crater that is believed to have also contained liquid water in its past. The findings suggest that the Martian crater will have a chemical composition comparable to that of Ries Crater. Therefore, studying the alkalinity, pH and nitrogen content of samples from the Ries Crater could help the researchers better understand the properties of ancient water on Mars and, in turn, determine the amount of carbon dioxide that was in the planet's atmosphere billions of years ago. Although complex life is unlikely, simpler microorganisms could have survived if water on Mars had a neutral pH level and was highly alkaline, the researchers said in the statement. These conditions would indicate that the atmosphere had enough carbon dioxide to warm the planet and make liquid water possible, the scientists added.
Neutral pH and alkaline ? (Score:2)
How does a solution have two different pH values simultaneously is what I'd like to know.
It's either one concentration or the other, unless you've taken it up with planning dept. upstairs.
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pH is a measure of Acidity vs Base. Alkalinity is a measure of how resistant to abrupt change in pH the solution is in the presence of added acids. You can have a high-alkalinity solution with a neutral pH. What this means, is that the solution can have added a good bit of acid before the pH will change significantly; however, when that change occurs it will generally be abrupt. Think of alkalinity as a measure of a buffer substance that can become a base when acid is added, thus neutralizing the acid, but,
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Dude, pH is the negative log base 10 of the H+ ion concentration at that instant. No more, no less.
Buffers affect how pH changes in response to changing the ionic concentrations. They don't allow a solution to have two pHs simultaneously, because the very concept is nonsense.
Yes: both neutral pH and alkaline (Score:5, Informative)
I had also thought that "alkaline" meant "high pH", but apparently in geochemistry the definition of alkalinity used is:
"Alkalinity is a measure of the capacity of water to neutralize acids. Alkalinity of water is due primarily to the presence of bicarbonate, carbonate, and hydroxide ions. Salts of weak acids, such as borates, silicates, and phosphates, may also contribute." Ref: https://www.sciencedirect.com/... [sciencedirect.com]
Other refs: "the alkalinity of a solution may be defined as the capacity for solutes it contains to react with and neutralize acid." https://pubs.usgs.gov/wsp/wsp2... [usgs.gov]
Wikipedia: "Alkalinity (from Arabic "al-qal"[1]) is the capacity of water to resist changes in pH that would make the water more acidic.[2] (It should not be confused with basicity which is an absolute measurement on the pH scale.) " https://en.wikipedia.org/wiki/... [wikipedia.org]
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I had also thought that "alkaline" meant "high pH", but apparently in geochemistry the definition of alkalinity used is:
"Alkaline" is a different word than "alkalinity", thus different definitions. Not sure what you guys aren't understanding.
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I've spent over 30 years working with people who also use "alkalinity" as a significant parameter to measure for well-drilling fluids. That's another subject where you don't deal with simple solutions of pure compounds, but you are literally looking at mud, with dozens of interacting impure components, w
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Not forgetting the birdshit too.
What has happened to scicence education? (Score:3, Insightful)
By the end of fifth grade I could have told you what's wrong with this sentence:
Their findings show that the samples have a high pH based on the ratio of nitrogen isotopes, as well as a high alkalinity, which indicates an imbalanced pH level, according to the study.
How many pairs of eyes had to miss the problems there in order for it to show up on space.com?
Still, it's not quite as bad as "if water on Mars had a neutral pH level and was highly alkaline", clearly added here at Slashdot.
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My brother lives in that crater (Score:3)
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(imagining your brother being chased around by Jörg Sprave, brandishing a repeating crossbow and shouting "Let me show you its features!")
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That is truly terrifying. I watched his repeating crossbow video the other day, and.... speechless.
Anyone who thinks slingshots are kids toys needs to hang out with Jörg for about 30 seconds to disillusion themselves.
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Small wonder (Score:2)
As any German can tell you, Bavaria is out of this world.
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But yeah, Bavaria is out of this world.
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"...analogue for Mars, and not necessarily a particularly good one.
But yeah, Bavaria is out of this world."
Perhaps Martians also wear leather shorts. :-)
Original paper. (Score:3)
i.e., it is hard to tell, from a small site or small number of sites, if the rocks you're examining are from a high-pH lake versus a neutral-pH lake or a low-pH lake. The arguments over how the Ries rock deposits formed went on for decades until it was settled in the late 1950s as being an impact structure. In particular, a volcanic origin which would most likely have been associated with carbon dioxide gases and a low-pH lake system was a contender. Geology isn't easy, even if the site is only a couple of day's travel away.
For exactly the same reason that distillation of H2O is an effective tool for fractionating heavy-hydrogen from mixed water, and diffusion of UF6 for fractionating nuclear fuel.
I'm not sure if any of the current fleet of Mars rovers have equipment for measuring delta-15-N in situ, but the proposed sample-return mission certainly has potential for performing this measurement.
Oh dear. The phrase "However, some microorganisms could have survived if ancient Martian water had both a neutral pH level and was highly alkaline." which has so exercised the armchair chemists comes from the UCR (University of California, Riverside) press release [ucr.edu] and it's author. Clearly, the press release wasn't written by a chemist. Or, for that matter, a Slashdot editor, who is due several apologies. The rule still stands : reading secondary sources is a waste of time - go straight to the original paper.
Re:Original paper. IS OPEN ACCESS (Score:2)
scientists see what gets them funding (Score:2)