The gullies on Mars are caused by a variety of factors, linked to both water and carbon dioxide
Click for original image.
In doing a detailed global analysis of all the known gullies on Mars, scientists now believe the gullies are formed by a variety of factors, linked to both water and carbon dioxide as well as the planet’s radically changing rotational tilt — varying from 11 to 60 degrees — over time.
Noblet’s paper articulates a “hierarchy of factors” that describes where gullies occur, with well-supported explanations as to why they form in one place and not another. None of the explanations in this paper are new. What’s new is how Noblet and coworkers reconcile apparent contradictions and inconsistencies among other researchers’ explanations of gully formation, explaining why an explanation that works for one spot on Mars doesn’t work in another.
The map above, from their paper, shows the global distribution of the gullies, which appear to favor the same mid-latitudes where the planet’s glaciers are mostly found. The data from many different studies suggests that when the planet’s rotational tilt was high, these mid-latitudes regions were warmer, and the near-surface ice there would sublimate away to get redeposited at the poles. When this happened the sublimation would cause the pole-facing gullies to form.
The paper also suggests that any gullies changing today are likely the result of the sublimation of carbon dioxide, not water.
There is a lot more at the article at the link, which is an excellent summation of this research.
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Click for original image.
In doing a detailed global analysis of all the known gullies on Mars, scientists now believe the gullies are formed by a variety of factors, linked to both water and carbon dioxide as well as the planet’s radically changing rotational tilt — varying from 11 to 60 degrees — over time.
Noblet’s paper articulates a “hierarchy of factors” that describes where gullies occur, with well-supported explanations as to why they form in one place and not another. None of the explanations in this paper are new. What’s new is how Noblet and coworkers reconcile apparent contradictions and inconsistencies among other researchers’ explanations of gully formation, explaining why an explanation that works for one spot on Mars doesn’t work in another.
The map above, from their paper, shows the global distribution of the gullies, which appear to favor the same mid-latitudes where the planet’s glaciers are mostly found. The data from many different studies suggests that when the planet’s rotational tilt was high, these mid-latitudes regions were warmer, and the near-surface ice there would sublimate away to get redeposited at the poles. When this happened the sublimation would cause the pole-facing gullies to form.
The paper also suggests that any gullies changing today are likely the result of the sublimation of carbon dioxide, not water.
There is a lot more at the article at the link, which is an excellent summation of this research.
Readers!
Please consider supporting my work here at Behind the Black. Your support allows me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Only now does it appear that Washington might finally recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
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