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Martian pits or dark splotches?

Martian pits or dark splotches?
Click for full image.

Cool image time! The photo to the right, cropped to post here, was taken on January 2, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a windswept sandy region of ridges and dunes with two dark features nestled between ridges.

What are these dark patches? At the available resolution they appear to be deep pits, with the one on the right having a significant overhang. And if these are pits, they would appear significantly different than most of the previously identified Martian pits, which are usually somewhat circular in shape. These features have very complex shapes, as if the pit is conforming itself to the terrain that surrounds it.

The resolution, however, is not good enough to confirm this interpretation. These dark patches could also be exposed volcanic material, darker than the surrounding terrain. The location, as shown in the overview map below, adds weight to this interpretation.

Overview map

The white cross indicates the location of these dark features, placing them inside the Medusae Fossae Formation, the largest deposit of volcanic ash on Mars. In other places in or near this formation where dust devils have blown the ash away the underlying volcanic material appears darker, though not exactly like this.

There is a third possibility, though more unlikely. These dark features might be volcanic vents, as this location is also located in what I like to label Mars’ volcano country. This is the least likely hypothesis, however, as the features bear little resemblance to other vents that I have seen so far on Mars. Can’t rule it out, however.

Ah, the uncertainty of science. Makes you want to go there and dig a little deeper to find out what these really are, doesn’t it?

Pioneer cover

From the press release: From the moment he is handed a possibility of making the first alien contact, Saunders Maxwell decides he will do it, even if doing so takes him through hell and back.

Unfortunately, that is exactly where that journey takes him.

The vision that Zimmerman paints of vibrant human colonies on the Moon, Mars, the asteroids, and beyond, indomitably fighting the harsh lifeless environment of space to build new societies, captures perfectly the emerging space race we see today.

He also captures in Pioneer the heart of the human spirit, willing to push forward no matter the odds, no matter the cost. It is that spirit that will make the exploration of the heavens possible, forever, into the never-ending future.

Available everywhere for $3.99 (before discount) at amazon, Barnes & Noble, all ebook vendors, or direct from the ebook publisher, ebookit. And if you buy it from ebookit you don't support the big tech companies and I get a bigger cut much sooner.


  • Alex Andrite

    “Cool image time! The photo to the right, cropped to post here, was taken on January 2, 2021 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).”

    elephant man.

  • Max

    Very unusual, curious.
    The lower right picture has a large circular rock like a big “cog artifact” in a lake of black goo…

    It’s the second time I noticed a circular object… In a prior photograph of a canyon contributing to a large flow that went off several cliffs… There’s a circular bridge crossing the canyon with a few objects on top of it. Too blurry to tell if it’s an obstruction, or a natural Bridge over the canyon.

    I’m inspecting this original picture, there’s a dozen black splotches on the ancient mud flood plain. No prominent “shadows” from the dune peaks… some of the black material appears along the crest of dunes like it’s a heavier particle different from the blown sand. (I wish it was in color, it might be dark blue) In other places, the blackness fills the low spots where there would be puddles or lakes.
    Because the position of the sun is mostly overhead, I don’t think they are windows. Dark material perhaps, uncovered by the weathering of billions of years. But this could be wrong as I can see lava flows? Like snake River beds all across the top of the picture. Now raised above the plain. Also in lower left at the base of one of the taller ridges with the largest deposit of black beneath it, the black has spread down wind like a vent, but it could just be the wind uncovering of some dark material underneath.

    So many mysteries. So many planets, so little time.

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