A Slice of Polar Layer Cake



The Martian ice cap is like a cake with every layer telling a story. In this case, the story is one of climate change on Mars.

This image of an exposed section of the north polar layered deposits (NPLD) looks much like a delicious slice of layered tiramisu. The NPLD is made up of water-ice and dust particles stacked one on top of the other. However, instead of icing, layers are topped with seasonal carbon dioxide frost, as seen here as lingering frost adhering to one of the layers.

The high-resolution and color capabilities of the Mars Reconnaissance Orbiter’s HiRISE camera provides details on the variations in the layers. Scientists are also using radar data, which show us that they have continuity in the subsurface. During deposition, these complex layers might encapsulate tiny air pockets from the atmosphere which, if sampled, could be studied to understand linkages to previous climates.

In the end, it’s not always a piece of cake studying NPLD on Mars but, where there is cake, there is hope!

Image Credit: NASA/JPL-Caltech/University of Arizona

Last Updated: March 11, 2020

Editor: Yvette Smith

35 thoughts on “A Slice of Polar Layer Cake

  1. Hmm, is it a climate if there is no one (or living thing) there to experience it?

    It is only a matter of time before someone blames fossil fuels for the “climate change” on Mars, and that it is worse than we thought.

    Meanwhile, why is the “climate” changing? Orbital related, Sol related, or what? Is it getting warmer, cooler? NASA??? You there? Maybe you could expand on the “climate change” theme so it has meaning?

  2. Carbon dioxide frost? It’s very cold at the Martian poles. Carbon dioxide freezes at -78 deg C, or -109 deg F. Maybe the CAGW true believers want to live there?

  3. Folks have been looking at the Martian ice caps for a while now. link I’m not sure what’s new about this story.

    The inconvenient thing about Mars is that it seems to be experiencing global warming roughly in sync with the Earth. That, of course, shoots holes in a couple of theories about Earth’s warming. For one, Mars doesn’t have clouds that can be affected by cosmic rays. The other is that Mars doesn’t have anthropogenic CO2.

  4. The science is settled:

    “Although the events that trigger dust storms have yet to be understood, this work demonstrates that one contributing factor may be a decrease in surface albedo. Martian climate indicators, such as global dust storm occurrences, polar energy balance, and annual global-mean air temperature, are dependent on many interrelated and poorly understood processes.


    Send for Jack Nicholson – just in case…

  5. I see where Elon Musk is saying his new Starship Moon/Mars vehicle can land on and take off from both the Moon and Mars on its own, although it will need a big lower stage to get the Starship vehicle into Earth orbit.

    Musk says he thinks he can get this new heavy-lift launch vehicle to put 100 tons of cargo in low-Earth orbit for about $2 million per launch, and believes he can launch the vehicle three times per day.

    Noone ever accused Musk of thinking small! 🙂

    Anyway, Musk is building the first Starship vehicle right now, and says he might launch a Starship vehicle to the Moon and land it there prior to the U.S. officially returning to the Moon in 2024.

    Musk ought to schedule an early flight to Mars and take a bunch of geologists so they can study things like the “layer cake”.

    Although I’m wondering how he is going to travel to Mars, land on Mars and then have enough propellants to take off from Mars. I suppose this would require a fueling station already located on Mars prior to the landing. Or else Musk’s Starship gets really good mileage.

    We need to get some boots on the ground on the Moon and Mars.

    Musk sure makes it sound easy. I guess the proof will be in the launch cost pudding.

    • Tom, you posted: “. . . although it will need a big lower stage to get the Starship vehicle into Earth orbit.”

      Well, it will also need a bigger second stage, and perhaps also a bigger third stage. There is NO chance that Musk/SpaceX can build a SSTO (singe stage to orbit) launch vehicle with today’s limitations on the performance of chemical propulsion.

      Heck, look at what the Saturn V “Moon rocket” took to launch that itty-bitty lunar lander and that itty-bitty three-man command & service module to Earth orbit and then to translunar orbit insertion. The Saturn V launch vehicle very likely used the optimum (even by today’s standards) propellant combination: relatively dense LOX/kerosene for the first stage and relatively high Isp LOX/LH2 for both the second stage and the restartable third stage.

      Furthermore, it is just not possible to send a manned exploration vehicle to Mars, using chemical propulsion, without in-orbit assembly of multiple components (modules) sent into orbit using multiple Earth-to-LEO rocket launches.

      Musk’s dreams cannot overcome the hard realities of combustion chemistry, physics and aerospace engineering.

      Prior to 2024? . . . Pfffftp!

      • What Musk needs to do is develop anti-gravity, then there’s no need for large boosters, very modest ones could then propel a ship where it needed to go. Simples!

      • Amen!
        I’ve set up just such architectures of necessary stages and various combinations of then to find any sweet spots, and these are mere computer simulations where the mass balances and stage sizings are well understood. Even these show that SSTOs are very dependent on mass fraction and do no suffer variation gladly. But then, these actually need to be built and there are all sort of nasty details like maintaining cryogenic storage of fuels in space. Merely transferring fuel is no minor task. It may be easier to swap tankage.
        Elon’s nice addition was to purchase the technology and hire the engineers who designed and built deep throttling engines necessary for propulsive landing. With out them the engines were optimized to perform at the primary flight conditions with a narrow range of throttling-down without shut down. The deep throttling however is not without a price as the peak performance suffers and they are heavier. …But they are mostly recovered/reused and that is a big cost savings.
        Elon ceased to be an engineer when he became a marketeer and has since slipped into hucksterism.

      • But, but, but Gordon, new-age thinking is that it can reach Mars using batteries and solar panels! Supplemented w/a strap-on windmill during the atmospheric ascent. ;);)

      • This business of building a stainless steel hulled ‘Starship’ to land on Mars comes as a bit of a surprise to me, given that Musk’s Dragon capsule was originally billed as being able to do that. I understand that the logic of this is that the Mars lander has to make use of aeorobraking in the Martian atmosphere to get anywhere close to a fuel-effective landing, and a stainless steel hulled design has better heat shedding properties for the aerobraking. The downside is that while steel has the required tensile strength and heat flow resistance, it doesn’t have the stiffness of some other materials, so the Starship has to be pressurized at all times to hold its shape — it is literally like a “steel balloon’.

        I have to say that I would take Musk’s dreams of space settlement a bit more seriously if he would get off the Mars kick, and establish that the Dragon capsule is really capable of landing on the surface of our own Moon. At that point, for reusability, maybe they’d have to also have to be able to land a “fuel tanker Dragon’ right beside, then refuel the manned Dragon for takeoff, and still have enough fuel in the specialized freighter that it could do a Lunar takeoff as well?

        In any case, I’m sure that the Moon is far more accessible than Mars, even given that it has essentially no atmosphere. Mars’ atmosphere is thin enough to be hard to make use of, to say the least, Mars is much farther away, you get more cosmic ray exposure just getting there, etc, and so forth.

  6. From the above article: “. . . instead of icing, layers are topped with seasonal carbon dioxide frost, as seen here as lingering frost adhering to one of the layers.”

    According to NASA and NOAA “climate” is weather over a specified location averaged over a continuous interval of 30 or more YEARS.

    See that word “seasonal” in the above quote?

    So, I conclude that NASA has gone bipolar (pardon the pun) in trying to apply the “climate change” meme to the surface of Mars.

    • You can get that effect on Tiramisu by dusting it with freshly ground espresso beans.
      It does depend on the origin of the bean and the roast.

      Maybe NASA’s next Mars probe will include a taste sampler module?

  7. Someone needs to tell Oregon’s Governor Kate Brown that Oregon’s CO2 emissions are far worse than even she imagined.

    If our CO2 emissions can cause the climate on Mars to change, we may be witnessing the demise of the entire solar system!

  8. NASA has put together several radar cross sections of Mars’ northern polar ice cap. The stratigraphic layering is very distinct.

    This cross section from MRO data was released in 2010:

    This image shows a cross-section of a portion of the north polar ice cap of Mars, derived from data acquired by the Mars Reconnaissance Orbiter’s Shallow Radar (SHARAD), one of six instruments on the spacecraft.

    The data depict the region’s internal ice structure, with annotations describing different layers. The ice depicted in this graphic is approximately 2 kilometers (1.2 miles) thick and 250 kilometers (155 miles) across. White lines show reflection of the radar signal back to the spacecraft. Each line represents a place where a layer sits on top of another. Scientists study how thick the pancake-like layers are, where they bulge and how they tilt up or down to understand what the surface of the ice sheet was like in the past as each new layer was deposited.


  9. You can’t create a viable atmos. on Mars because there is’t any real Gravity. How do you hold O2 when the sun beats the atmos. You people on Earth are lucky.

    • Yep, we have all that handy oxidizing O2 just hanging around thanks to our foresight in installing some advanced chlorophylic nanobiotechnology.

      It creates something of a fire hazard I know, but what can you do, can’t have everything.

  10. “However, instead of icing, layers are topped with seasonal carbon dioxide frost, as seen here as lingering frost adhering to one of the layers.”

    CO₂ does not freeze or melt from/to a liquid state. Istead is accretes from CO₂ gas and sublimates to a gas.

    As teflon and many other substance prove, liquid water is blocked from penetrating where H₂O vapor freely travels through.

    The same is true of CO₂. What these folks are claiming are CO₂ “layers” are unlikely to have been laid down in succession.

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