Clouds Get in the Way on Mars


The science team from the HiRISE camera on the Mars Reconnaissance Orbiter wanted to take another look at a region of icy sand dunes on Mars to look for seasonal changes as spring is now arriving on the Red Planet’s northern hemisphere. But the view was obstructed by clouds, creating this unusual hazy view.

“This happens occasionally. We’ve found that weather forecasting on Mars is just as challenging — if not more — than on Earth,” said HiRISE team member Candy Hansen, who I nabbed in the hallway during the Lunar and Planetary Science Conference today, to ask about this unique image. “The clouds are likely made of water ice crystals, and the dunes have a coating of CO2 ice that is just starting to sublimate away as the Sun’s rays are getting stronger in this region.”

Hansen said these are dark barchan, or crescent-shaped dunes. During the winter, this region was completely covered with carbon dioxide ice, but now just the the tops of the dune have ice; also visible are what looks like white cracks, which is ice protected in shallow grooves on the ground. HiRISE will likely check back on this region later during the Martian summer to provide the science team with a seasonal sequence portfolio of images of the region, a benefit of having a mission in orbit for several years. MRO and HiRISE are workhorses, having been in orbit since March of 2006.

See the original image on the HiRISE website.

9 Replies to “Clouds Get in the Way on Mars”

  1. I know its another optical illusion or whatever but what is it with Mars and human faces?

      1. Nope. That’s Romeo, my goat! But off to the left looks to be Thomas Jefferson.
        Now, I know goats are curious, but I’ve no clue what Tom is doing on mars.

  2. Not only is there the face, but the clouds are reminiscent to me of the classic 50’s “flying saucers”. Dick Hoagland must be having a FIELD day with this image………

    1. Those are not the clouds, JSB, those are the dunes capped with CO2, rather; the clouds are the wispy things you are viewing through to see the more solid dune tops. The spider web of frozen water ice is closer to the ground level than the tops of the dunes. These dunes are tens to hundreds of meters above that surface.

      The face like object is another of the dunes capped with CO2 frost and seen through a hole in the clouds. The circular vignetting draws your eye to that feature in the clear area. The stark contrast of the flat lands around that dune and the angle and type of the lighting, the type of filtered sun light the clouds are producing, all enable our brains to see a half lit face with neck and hair. Turn the photo upside down or orient that photo differently and you will see less of a face and more of the reality.


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