Have these Martian dunes changed in sixteen years?
Click here and here for the original images.
Cool image time! The two pictures above, both rotated, cropped, reduced, and enhanced to match and to post here, were taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) sixteen years apart. The first, on the left, was taken on February 23, 2007, while the second, on the right, was taken on November 1, 2023.
What drew me to both images was the label for the second: “Dune Change in Arabia Region Crater.” To find out if this image had revealed any changes in the dunes I went back and found the earliest MRO picture of this location, and sized and enhanced the dunes in both to match.
Do you see any changes? I don’t. However, that really means nothing. These are not the highest resolution versions that MRO obtains, and a very careful comparison of those best images might detect more subtle changes than our eyes can perceive in the versions above. Also, there might be brightness changes that require careful software analysis.
The white dot on the overview map to the right marks the location, in Arabia Terra, the largest transition region on Mars between the northern lowland plains and the southern cratered highlands. The inset shows the half filled crater in which these dunes sit. The grayed area on the floor of the crater marks the entire dune field, extending eastward to the crater rim from this one spot, indicated by the black dot.
It is likely that the dust is blown into this crater and gets trapped there. Whether the dunes move or change is not clear, though if they do the changes are small, even after almost two decades. Instead, the two pictures suggest these dunes have hardened into a form of sandstone, that can be eroded over time by the wind, but only very very slowly.
The support of my readers through the years has given 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. Four years ago, just before the 2020 election I wrote that Joe Biden's mental health was suspect. Only in this year has the propaganda mainstream media decided to recognize that basic fact.
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. Even today NASA and Congress refuse to 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.
Please consider supporting my work here at Behind the Black.
You can support me either by giving a one-time contribution or a regular subscription. There are five 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.
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Click here and here for the original images.
Cool image time! The two pictures above, both rotated, cropped, reduced, and enhanced to match and to post here, were taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) sixteen years apart. The first, on the left, was taken on February 23, 2007, while the second, on the right, was taken on November 1, 2023.
What drew me to both images was the label for the second: “Dune Change in Arabia Region Crater.” To find out if this image had revealed any changes in the dunes I went back and found the earliest MRO picture of this location, and sized and enhanced the dunes in both to match.
Do you see any changes? I don’t. However, that really means nothing. These are not the highest resolution versions that MRO obtains, and a very careful comparison of those best images might detect more subtle changes than our eyes can perceive in the versions above. Also, there might be brightness changes that require careful software analysis.
The white dot on the overview map to the right marks the location, in Arabia Terra, the largest transition region on Mars between the northern lowland plains and the southern cratered highlands. The inset shows the half filled crater in which these dunes sit. The grayed area on the floor of the crater marks the entire dune field, extending eastward to the crater rim from this one spot, indicated by the black dot.
It is likely that the dust is blown into this crater and gets trapped there. Whether the dunes move or change is not clear, though if they do the changes are small, even after almost two decades. Instead, the two pictures suggest these dunes have hardened into a form of sandstone, that can be eroded over time by the wind, but only very very slowly.
The support of my readers through the years has given 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. Four years ago, just before the 2020 election I wrote that Joe Biden's mental health was suspect. Only in this year has the propaganda mainstream media decided to recognize that basic fact.
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. Even today NASA and Congress refuse to 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.
Please consider supporting my work here at Behind the Black.
You can support me either by giving a one-time contribution or a regular subscription. There are five 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:
5. 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. And if you buy the books through the ebookit links, I get a larger cut and I get it sooner.
I can’t see changes either. It would be interesting to put the two images into a blink comparator a la the discovery of the PLANET Pluto.
Andi: Before I put both images into one, side-by-side, I had them aligned on top of each other, and could quickly go from one to the other. No obvious changes noticeable.
Slight change on the thin teardrop tail half way up on LHS.