More weird Mars geology

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Low resolution of full image of crater

Cool image time! Yesterday the Mars Reconnaissance Orbiter team released 460 images taken by the spacecraft’s high resolution camera, HiRISE, as part of their normal and routine image release program. Obsessed with space exploration as I am, I like to scan through these new images to see if there is anything interesting hidden there that will show up eventually in a press release. For example, the first image in this release is a look at Vera Rubin Ridge and Curiosity. I would not be surprised if there is a press release soon using this image, probably aimed at outlining the rover’s future route up Mount Sharp. (The present overview traverse map is getting out of date.)

Sometimes however I find images that might never get a press release but probably deserve it. The image on the right, reduced in resolution to show here, is one such example. It is a strip taken from rim to rim across an unnamed crater located in the mid-northern latitudes of Mars, west of Olympus Mons. A review of past images by other Mars orbiters/probes suggests that no good high resolution image of this crater had ever been taken before.

If you click on the image on the right, or go to the actual image site, you can see the original in full resolution. It is definitely worthwhile doing this, because the strip shows some strange and inexplicable geology on the floor of the crater as well in its confusing central peak region. Numerous features appear to have been exposed by later erosion. The many small craters for example are I think what planetary geologists call pedestal craters. The surrounding terrain is less erosion-resistant, so as that terrain erodes away it leaves the crater behind, with its floor actually sitting higher than the surrounding flats.

What makes these craters even weirder however is that their rims appear to have eroded away even more than the surrounding terrain, so that all of these small craters (assuming that is what they are) have ringlike depressions surrounding a circular platform.

In the crater’s central peak region the terrain is even more strange. Sticking up out of the ground are some arched short ridgelines, which appear to have been exposed by erosion. That peak area however also has many strange flow features that I find completely baffling. It almost appears to me that as the molten peak area started to solidify after impact, someone went in with a stirring spoon and did some mixing!

The map below the fold provides the location context for this crater, with the crater’s location indicated by the arrow.

The red squares indicate other HiRISE images. The terrain colors indicate altitude, with the significant altitude differences indicated by me. These elevation numbers are critical, because they show that the crater is located in the transition zone between Mars’s cratered southern highlands and its smooth and flat northern plains, a region that some scientists believe might have once been a shallow ocean. It is this transition zone where we would find the ocean shoreline, if such a thing ever existed on Mars.

The geology exhibited here, however, does not indicate a shoreline. Instead, it suggests a gradual change in the past from the high dry south to the low wet north. Ice is very likely buried here, and its properties in the low Martian gravity and cold climate and low atmospheric pressure probably contributed in creating these strange geological features. And if there was an ocean to the north, I would not be surprised if its edge shifted with time, kind of like the changes we see on a beach as the tide comes in and out. With each shift in and out the change in water and ice properties will leave geological changes that to our eye now, from this distance and with our presently limited knowledge of Mars, remain puzzling and difficult to explain.

In writing up this post, I was originally going to crop out some of these strange features from the full resolution image and highlight them. I have changed my mind. You should click on the image and explore it for yourself, I would be very interested in some serious speculation by my readers as to the geological processes that might have caused these features to form.



  • BSJ

    Looks like caters in ice to me.

    Earthbound analog at a much smaller scale.

    Interesting that there are so few modified craters. Other sites have had many smaller simple craters. So this site must be quite “young”.

  • BSJ

    Argh. So many UN-modified craters…

  • BSJ


    So FEW UN-modified craters

  • Orion314

    Mr Z, nice article! , I’d like your expert opinion re: the feasibility on the use windmill type power on Mars. There is a new base building game coming out on 15 march , called Surviving Mars, and in addition solar power , they have these cool looking wind turbines in the sim. I maintain that the air pressure is far too thin for these to work. What say you?

  • Orion314: Thank you for the kind words, but I never claim to be an engineer. I am not the one to ask this question. You need to hope that the very qualified engineers who read and comment here see your question and attempt to answer it. I’d be very interested myself on the answers.

  • wodun

    We need a bat signal for the engineers.

  • Orion314

    I like your idea!

  • wayne


    I’m almost positive the ‘wind-turbine-on-mars’ thing, has been addressed here before by more than one person, but I don’t recall specifics. (I want to say Edward, among others, provided some calculation’s, at some point, but I just don’t know.)

    IIRC, it may have come up ref: the movie the Martian, specifically the damage the initial wind-storm was portrayed as causing.

    From what I understand, the wind speed can get going pretty fast on Mars, but the force it can impart is a function of the low atmospheric pressure.

  • wayne


    check out this link:

    scroll down past the Question, for the post starting with;
    “Lets do some Maths”

    brief summary:

    dynamic pressure or velocity pressure produced by wind, is computed with the formula:
    “q= 0.5pv(squared)”

    A 60mph wind on Earth would produce “440.48 Pa”
    A 60mph wind on Mars would produce “7.192 Pa”

    The only thing I don’t know, is how many “Pa” units are required to spin a turbine blade for mechanical or electrical energy production.

    (I’m just a “behavior-engineer,” but I’m doubting wind-turbines would actually function.)

  • Orion314

    I have very serious doubts about the efficacy of wind powered anything on Mars. For all practical purposes , as far as humans are concerned, the surface of Mars IS outer space.The average surface pressure on Mars is .087 psi. Around an earth altitude of 24 miles or so. If you see the videos of Felix Baumgartner leaving his balloon gondola ~128,000 feet , you’ll notice no wind resistance of any kind on his SPACE suit. Not even the slightest flutter.. see for yourself1

    start at 3:30 for the jump


  • Andrew_W

    To have the wind pressure available to extract the same energy as one on Earth a Martian wind turbine would have to have about 60 times the rotor area or about 8 times the rotor diameter – that’s with similar wind speeds. with lighter blades due to lower loads and lighter and stronger materials available in a few decades I don’t think there are engineering show stoppers. But there is the question of whether or not there’re locations on Mars with reliable enough wind patterns (only a small fraction of Earth’s surface is good for wind energy), and also the cost of other possible energy sources is crucial to the economics.

  • Dick Eagleson

    That thing at the top of the posted image strip looks to me like wormsign. ;-)

  • wayne

    Hhmmm…. physics never stops the fools on Earth, I don’t expect Mars to be a whole lot different. -We’ll just get the Mars Central Bank to issue all the money we need, and through innovative private-public partnerships, we’ll overcome the challenging obstacles and construct the Mitch McConnell Memorial Wind-Farm, on Mars. (Mars needs good-jobs, at good-wages, and just think of the children….freezing in their bio-domes at night, begging for scraps of electricity. If we could save just one child, it would be worth it.)

    Thanks for that Felix video–I’ve never seen the head-cam view.

    Chapter 20; “In the Atmosphere Factory”
    from “A Princess of Mars,” Edgar Rice Burroughs.

  • Andrew_W

    Wayne: “physics never stops the fools on Earth. . . ”
    I think you might mean “economics never stops the fools on Earth”.

  • wayne

    Andrew_W; (what Time is it, in NZ?)

    HA! I did mean physics, but I’ll take economics. (That never stops the mastermind’s, either.)
    I actually have a Minor in Environmental Studies, and that was a tortuous endeavor on my part. (late 70’s) I was infinitely more idealistic at the time, but I quickly discovered the whole department was left-over hippy-marxists, with tenure. (and this was when the coming Ice-Age was the hot-topic they were pushing, with the absolute certainty & zeal, only authoritarian-utopians can muster.)

    Just don’t Blab, about Mars…
    (from Total Recall)

  • Andrew_W

    (what Time is it, in NZ?) 6:54 am 4/3/2018 (d/m/yr)

  • wayne

    -thank you. (you’re living in the Future….)

    (I’ll have to look up the history of the “month-day-year” vs. “day-month-year” convention. That always irritated me to no end whilst reading European origin history books.)

    anyway…. to summarize loosely;

    Mars is an alien environment although it looks sorta like the American west, on a fuzzy scale.
    “Wind Turbines” are a no-go on Mars
    We need the flashing Bat-Signal for Emergency-Engineering-Input, on the masthead here, alerting engineers of a Question, (along the lines of what Drudge does with the rotating red police-light.)
    “They” just discovered a previously unknown penguin-colony (1.5 million) on Earth, so we really need to rule out Polar Bears on Mars, once and for all. (If there is Just One Polar Bear on Mars, that we can save, it would all be worth it.)
    Wilbur Ross is going to handle imposing export tariffs to/from Mars, and McConnell’s wife will handle the more-shovel-ready, public + private partnership (stakeholders will be consulted) Martian-Infrastructure-Project, so we can harvest all this ice on Mars, by hand.
    “It takes a Village, to colonize a Planet.”

  • Andrew_W

    Remember Wayne, “engineering without numbers is only an opinion”, so even if your engineer turns up, unless he/she is willing to do all the necessary research, it’s only an opinion.

    The simple number is that at any given wind speed, there is only 1/60th of the energy available in the wind on Mars as on Earth.

    Viking Site Measurements
    The sites of the Viking landers are some of the best-studied regions on Mars. Like the wind speeds of Earth, the average Martian wind speeds varied by season. At the Viking sites, the average wind speed registered at 2 to 7 meters per second (5 to 16 mph) during the Martian summer. During the fall, the average wind speed increased to 5 to 10 meters per second (11 to 22 mph). Across the year, the wind speed on Mars averaged 10 meters per second (or 22 mph).

    Those figures surprised me, I was expecting average wind speeds to be much lower, so I suspect in places where there is rough terrain that there could be locations where wind speeds are significantly higher than at the Viking sites.

    The other issue is what competition wind has from other energy sources? Solar and nuclear are the only ones that come to mind. Solar gets crippled in a big dust storm but is otherwise reliable, nuclear is obviously good all the time, though cooling could require quite a bit of hardware in dryer locations, but if you’re setting up where there are large subterranean ice deposits, which is likely, I expect it would be possible to just melt those deposits, creating underground lakes for cooling – just make should you don’t make the lake too close to any structures!

    So my betting is that nuclear will be the principle energy source with solar definitely used and wind also possible in niche situations and locations.

    I’m puzzled that you think “physics never stops the fools on Earth. . . ”, in NZ the laws of physics are pretty inflexible and as far as I know we’ve never had anyone actually breaking them, we did have that Rutherford guy but I don’t think even he actually broke the laws of physics.

  • Max

    I am not an engineer, but I can put some numbers in perspective. Earth has one bar of pressure/1000 mbar. (That is an average at Earth’s 45°, the pressure is higher at the equator and lower at the pole)
    Mars has 7 mbar of pressure on average. (Slightly more in the northern hemisphere then in the highland south).
    That’s 993 mbars less than earth, 7 more than outer space.
    Wind on Mars at 700 miles an hour will stir up the dust, but would have very little pressure to do any mechanical work. If it was not the case, I think the Rovers would’ve told us differently by now.
    Attaching a large windmill on a tether to an astroid moving through the solar system would have 7 mbar less pressure than mars, but the solar wind moves at 2 million mph. Like a comets tail, the windmill will always shift to face away from the sun.
    (Has anyone done any solar sail experiments yet? I’m curious to know which has more force of pressure. The solar wind, or a surface of black material soaking in light and radiating heat like a radiometer toy that spins in the sunlight:)
    The only way I can see a windmill on Mars performing any work is if it is very large, made out of super light material like mylar with carbon fiber supports. Not much reinforcement is necessary.
    Compare that to Venus which has over 90 bars of pressure. Air speed of 1 mph would have the equivalent pressure of over 90 mph on Earth. That is not quite true because air there acts more like a fluid. A 860 F hot fluid.

    There is a theory that a wind of ionized gas blows from the hot side of mercury to the 300° below zero side. Probably would not be very practical for a windmill or an ion collector. Solar panels would degrade 5 to 10% in every solar storm from radiation damage.
    I picture the best way to produce power on mercury is to lay out black pipe to boil water in side of that will turn a turbine just like off-the-shelf here on earth. To cool the steam back to a liquid, just run the return line in the shadow of the boiler pipe.
    Picture a large circular dish as a heat collecting boiler tank above a mobile caravan or city that not only acts as a power generator, but as a giant radiation shield. Green houses along the outer edge will collect the reflected light from the surface while staying cool in the shadow of the dish. Mercury spins so slow that you can out run the sunrise.
    This idea can be Proto typed on our moon.

    Sorry, my imagination got away with me again.

  • Garry

    I have an engineering degree, but have little practical experience applying most of what I’ve learned, so it’s doubtful that my comments carry any more weight than Wayne’s or Andrew’s. But I will comment that if we made the windmill arms 8 times as long, as Andrew proposes, the arms would probably have to be heavier (based on Mars’s gravity being fairly close to earth’s, and the tips rotating at 8 times the speed for a given rpm, thereby inducing more load). The heavier arms would make the frictional forces heavier. If we could make some bearings that would maintain very low friction, this may not be much of an obstacle.

    What I really wanted to comment on was Wayne’s statement

    “(I’ll have to look up the history of the “month-day-year” vs. “day-month-year” convention. That always irritated me to no end whilst reading European origin history books.)”

    This is one area where I agree with the European convention; we start with the smallest unit (day), then to the middle unit, then to the largest unit. If I have several computer files I need to keep, I’ll append the date to the end of the file, in the manner of 180304 (year-month-day), or the reverse of the European order given above; this way they appear in chronological order. Of course, I run into the same problem Wayne does when reading, and wish that we had adopted the European convention from the beginning.

    The other British writing convention I agree with is placing commas and periods outside quotes, in the manner of “quote”, or “quote”. as opposed to the American manner of “quote,” or “quote.” I edit a lot of manuals that instruct the user to input various things in apps, programs, etc., and when I want to tell them to input [end], if I use the American convention of [input “end.”] they’re may input [end.] instead of [end] , so when I can get away with it, I write [input “end”.]

    Don’t get me started on the problems with spelling in English

  • wayne

    Good stuff.
    (Always highly interesting material from your end!)

    Because you can’t talk Batman without Penguins….

    “1.5 million “super-colony” of Adelie Penguins discovered”
    March 2, 2018 (03-02-2018!)
    “…satellite images revealed the presence of more guano on the rocky islands than could be explained by the colony’s previously assumed, but not verified, number of birds.”

  • Chris

    There are no experts (engineers, scientists, otherwize). There is only data and proven theory supported by that data. I retired after 30+ years in engineering. The degree does not bestow magic upon you. That piece of paper only states that at one point in time someone was willing to vouch that you displayed some modicum of engineering proficiency. Even the engineering license is about passing a test at one time. Many a non-degreed individual out think and out produce the best pedigreed “engineer” daily.
    Indeed, with the shortage of scientists and engineers we see many companies forgoing the requirement of a degree. Since we are no longer an inspired populace for STEM in the US – no Apollo program, no Star Trek…, the number of kids who want to be engineers (and do the math) is lower than the demand. Maybe SpaceX can inspire this next generation…
    Sorry rambling again….

  • wayne


    Crony Chronicles:
    “I Want To Be A Crony…”
    august, 2012.

  • Orion314

    Dick ,
    re: wormsign , good call!

  • Edward

    Sorry for missing the Martian wind turbine discussion. I have not done any propeller calculations since college, and that was only for Earth wind turbines or airplanes. I would have to find my book (yes, I kept my college books), but I think that everyone here already figured out that solar arrays (photovoltaic) are generally more economical than wind on Mars.

    Chris is right. The degree really only helps in making us do the math and understand a few things that are counterintuitive, but there are several concepts that are easily understood, just like the lower effectiveness of Martian wind turbines.

    Has anyone done any solar sail experiments yet?

    Yes. There have been at least three solar sails taken to Earth orbit for experimentation.

    The idea of the solar sail is that it reflects the light and gets twice as much force as the radiometer’s black body. Both sides of the sail and the radiometer would radiate any heat that is collected, although the radiometer’s black body side would be more efficient at it. The reflective solar sail is more efficient than having a black body side and a low radiative side, like the radiometer.

    Please do not confuse the solar wind (ions) with the light pressure that a solar sail relies upon. Light has a certain momentum, and it is the change in that momentum that provides the change in the sail’s momentum.

    I picture the best way to produce power on mercury is to lay out black pipe to boil water in side of that will turn a turbine just like off-the-shelf here on earth.

    In late 2001, I visited an Earth power plant that did something like this in the Mojave Desert. They ran oil in the pipe, because they could get it hotter, and they had the pipe in a trough of a parabolic mirror to get the oil up to around 400 degrees (F or C, I don’t remember). The oil went to a heat exchanger to boil water, and the water was also superheated with fossil fuels to increase the overall thermodynamic efficiency.

    I am in agreement with Garry’s date comments. Filenames should use a different date stamp than for everyday use, where the day of the month is often more useful at the front than the month of the year.

  • Orion314

    I always thought the only logical method for that was : YYYY/MNT/DAY/HR/MIN/SEC

  • wayne

    I’ve only gotten as deep as Wikipedia so far;
    -lot of factoids but not much functional history-

    they do reference ISO 8601 which covers -“Data elements and interchange formats – Information interchange – Representation of dates and times.”

  • Max

    Fascinating Edward,
    Some oil’s can withstand high temperatures without breaking down or turning into a vapor. I know that early automobiles used oil in there cooling system for its ability to conduct heat, lubricate the pump, non-corrosive qualities… But when a leak occurred it also turned you into a fireball.
    In the heat collection and exchanger, I wonder if the application you described could also use mercury. I’m sure there are reasons that they shouldn’t, but I think it would be more efficient because of its mass. I wonder if mercury produces pressure as a vapor? (I believe molten salt is what they currently use, it’s nontoxic, cheap, plentiful, easily cleaned with water but is very corrosive)
    Water has the largest expansion properties of any fluid when turned into a gas. The hotter the water, the more the molecule flexes outward with pressure making it the best medium to drive a turbine. (Or a rocket motor in a different method of making water)
    This is also true in nature when a storm is formed they can calculate how much water is there by the barometric pressure. Water expands far more than it should, displaces air and is lighter then oxygen and nitrogen causing a low pressure system which sucks the air causing wind. The low pressure also causes the temperature to drop. In truth, this is just as amazing as its ability to expand and become lighter when it turns into a solid. (ICE)

    As for power generation on Mars, with average airspeed of 22 mph (thank you Andrew_W) The energy required to create massive wind farms for so little return would not be cost-effective and difficult to maintain. The only thing working in the favor of Mars is the low surface gravity .37g ( Mars is .53 earths radius, 1/10 of earths mass. As compared to Mercury which is smaller, has near the same surface gravity as Mars, according to Wikipedia).
    I agree on solar panels. They will produce power with less maintenance. The solar panels will need to be manufactured on Mars, The infrastructure will not be easy. (Technology on the other hand is always changing)
    On earth, solar panels are getting better and have reached the point where their lifetime energy production is equal to the energy to create them.
    having almost no atmosphere on Mars compensates somewhat for the 1.5AU distance. Light is dimmer. Increased UV, which is filtered out in earths atmosphere, may increase power production but decrease the lifespan of a solar panel.
    I still think that plutonium batteries, as discussed in a prior thread, are the best source of energy/heat and would provide the foundation for the infrastructure of everything that could be needed in a young colony. There is more CO2 in the ice caps then there is atmosphere on Mars. The heating of CO2 with a nuclear battery, which will stay hot for hundreds of years, will not only produce pressure to turn a generator for power production, but provide heat for the habitation quarters, the largest energy consumer, and make rocket fuel with energy to spare for other necessities like food production, metallurgy, raw materials for 3-D printers to make the tools and replacement parts that will never come from earth. evaporate tunnels in the ice cap without machinery… all of this with minimal infrastructure and the C02 released into the atmosphere will simply re-freeze and fall Like snow to be recycled.
    The world has plenty of spent reactor rods looking for a place to store them. The energy to mass ratio in launching them to Mars will pay for itself, unlike any other energy source. Mars has a unique condition where these spent rods could produce the power for a large self-sustaining colony. Where “need is the mother of invention”, New products and technology will spring forth from such a place. Survival is depending on it.

    A radiometer will not spin in a pure vacuum. It needs a little air for the heat to have a mass to push against. I know the earth is technically inside the atmosphere of the sun, I’m not sure if the heat radiating has enough atmospheric mass to work against.
    The solar wind does not have enough mass to blow anything useful. Perhaps when the new thermalscope is placed in the L2 with the huge heat shield, we will hear about it if a solar storm pushes it out of position. An unintended experiment.

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