The strange surface of the perennial dry ice cap at Mars’ south pole
Click for original image.
Cool image time! The picture to the right, cropped to post here, was taken on January 24, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a region about 180 miles from the south pole of Mars.
This terrain is intriguing because is the pattern of ridges that cover it entirely. I have simply cropped the original image to show these ridges in highest resolution. The full image shows them covering a region much larger than this.
What are we looking at? Because it is near the pole, it is likely that the black splotches are caused by carbon dioxide gas breaking through the winter mantle of dry ice that covers the poles during the winter months and then sublimates away, from the bottom, each spring. As the dry ice turns to CO2 gas that gas is trapped, until it can find a weak spot in the overlying mantle. When the pressure builds enough, the mantle breaks, the gas escapes, and as it does so it deposits the dark dust around the breakage. That dust fades as the mantle disappears.
Sounds good, eh? Not so fast.
The red dot on the overview map to the right marks the location of this patterned terrain, sitting on top of the perennial dry ice cap at the south pole.
In other words, the surface here is always dry ice, year round. During the winter months an extra temporary mantle of dry ice might form, but it is only doing it on top of thicker permanent dry ice. Why this mantle of dry ice should sublimate away but the older permanent dry ice doesn’t remains a question that I have asked scientists several times, without a good answer. Essentially, it is a mystery that is not yet understood.
Moreover, the mystery is deepened in that there is no permanent dry ice cap on the north pole. For unknown reasons, only Mars’ south pole retains a dry ice cap year round, though there is also evidence that, at least in some places, it is slowly going away. Other data however suggests its dry ice glaciers are growing, suggesting the dry ice is instead expanding.
At this location, the dry ice instead resembles material that, as it froze, it shrank, causing the wrinkle ridge pattern across the entire surface.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Click for original image.
Cool image time! The picture to the right, cropped to post here, was taken on January 24, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a region about 180 miles from the south pole of Mars.
This terrain is intriguing because is the pattern of ridges that cover it entirely. I have simply cropped the original image to show these ridges in highest resolution. The full image shows them covering a region much larger than this.
What are we looking at? Because it is near the pole, it is likely that the black splotches are caused by carbon dioxide gas breaking through the winter mantle of dry ice that covers the poles during the winter months and then sublimates away, from the bottom, each spring. As the dry ice turns to CO2 gas that gas is trapped, until it can find a weak spot in the overlying mantle. When the pressure builds enough, the mantle breaks, the gas escapes, and as it does so it deposits the dark dust around the breakage. That dust fades as the mantle disappears.
Sounds good, eh? Not so fast.
The red dot on the overview map to the right marks the location of this patterned terrain, sitting on top of the perennial dry ice cap at the south pole.
In other words, the surface here is always dry ice, year round. During the winter months an extra temporary mantle of dry ice might form, but it is only doing it on top of thicker permanent dry ice. Why this mantle of dry ice should sublimate away but the older permanent dry ice doesn’t remains a question that I have asked scientists several times, without a good answer. Essentially, it is a mystery that is not yet understood.
Moreover, the mystery is deepened in that there is no permanent dry ice cap on the north pole. For unknown reasons, only Mars’ south pole retains a dry ice cap year round, though there is also evidence that, at least in some places, it is slowly going away. Other data however suggests its dry ice glaciers are growing, suggesting the dry ice is instead expanding.
At this location, the dry ice instead resembles material that, as it froze, it shrank, causing the wrinkle ridge pattern across the entire surface.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
“Moreover, the mystery is deepened in that there is no permanent dry ice cap on the north pole. For unknown reasons, only Mars’ south pole retains a dry ice cap year round”
Perhaps the answer to the mystery lies in their differences? Here’s my best guess.
On earth, the north pole melts every year because it’s warmer at sea level. Antarctica average height is near 10,000 feet and never melts…
The northern hemisphere of Mars is lower in altitude than the Southern Hemisphere. Although the boiling point of water will be higher with higher air pressure, evaporation becomes more efficient. (Mars average is 7 mbar… making freeze dried food, boils/vaporizers water at subzero temperatures at 6 mbar). So is the temperature is higher due to atmospheric pressure… What little atmosphere there is.
It appears that Mars is losing atmosphere into space, and that more frozen CO2/water boils/vaporizes/supplicates off when the millibars of pressure drops too low. Thustly it will maintain a constant air pressure until there is no ice caps left.
The northern hemisphere is very smooth as if the entire planet impacted with a larger planets thick atmosphere at one time depositing a considerable amount of the northern crust in to the southern hemisphere)
The southern hemisphere is full of mountain ranges, impact craters, and more exposed surface in general. It’s also colder due to less air pressure.
Here’s an illustration provided by NASA detailing actual measurements of a 10 year average of “watts per meter squared” of incoming radiation and outgoing radiation from the earth. Notice that the “earth emits more energy” than it receives at the top of its atmosphere… (And this illustration is only relevant during the daytime, earth emits energy all night long with no incoming energy).
https://www.nasa.gov/centers-and-facilities/langley/what-is-earths-energy-budget-five-questions-with-a-guy-who-knows/
Don’t bother with the article, they see nothing wrong with actual measurements not making sense, and tend to ignore the elephant in the room… that the numbers cannot be explained with accepted climate models. Especially the mythical greenhouse emitting as much energy as the sun at noon! A violation of the second law of thermodynamics… There’s no way a freezing cold upper atmosphere can be “heating” the ground! Madness.
A greenhouse event has never been measured although satellites and weather balloons have been looking for it for over 40 years. (temperature drops 5.4° for every thousand feet higher you go)
The Chinook winds are well documented, and holds the Guinness book of world records for the largest amount of heating in the shortest amount of time. And yet, you will not find this record holding atmospheric phenomenon in any global warming models!
Cool picture (pun intended) I like to think of these vents as possible caverns beneath the ice ready for habitation.
Hopefully I’ll live long enough to see folks to go there and resolve these mysteries.
I also still believe the first settlements should take advantage of the accessible resources of the of water, methane and nitrogen in the ice cap. A robotically controlled heat source is all that’s necessary to tunnel, process the gases, and create pressurized living arrangements (if the ice has no cracks).
The processed carbon is an efficient insulator to hold in heat, or grow food… Breathe the oxygen.
There will be no colony without a considerable source of energy, nuclear is the most compact and best researched for variable conditions providing the largest amount of heat reliably for the longest period of time. One nuclear reactor can create many more nuclear reactors… Try that with a solar panel.
The Atomic heating of dry ice into a high-pressure liquid to provide power through a two stage turbine is more efficient then water, with a byproduct of caverns that can be pressurized for a colony! (At least until heavy equipment can be manufactured for underground settlements) The released CO2 gas will refreeze in the cold environment, making the availability even simpler, practically self-sustaining with a heat source. If uranium is discovered anywhere outside of earth, it’s game on for the rest of the solar system!
Now that I think about it, I wonder if CO2 will have more thrust than (H2O)2? When used as rocket propellant? The exhaust gases from the thrust bell could pass through a light weight heat absorber/condenser collecting and recycling the water or CO2 to be returned to the rocket fuel tank to be reused in the superheating thrust motor making the rocket self-sufficient, consuming no fuel for long duration burns. With a breeder reactor recycling the plutonium back into uranium this could last for hundreds of years…
Now I’m dreaming….
But this could be used to move astroids and comets… The fuel not escaping the astroids gravity, freezing to the surface to be gathered up and placed back into the reactor?
Move potential ice moons into a Martian or lunar orbit? Or better yet, a miles long “generation ship” heading to new solar systems under one G thrust… with the reaction motors at the top of the ship under the protective micro meteor dome connected to a thin outer double shell so the exhaust gases pass along the length of the ship keeping it warm, while condensing/ capturing 100% of the propellant gases for reuse, becoming liquid by the time it reaches the tank end of the generation ship… (Good idea for a sci-fi novel)
It all starts under the Martian polar ice cap!