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The February 27 Astronomy Picture of the Day has a picture of the Perseverance landing region taken by the Mars Reconnaissance Orbiter. The landing site itself has a distinctive look:

Perseverance landing site Closer landing site view

The left image is from the APOD page, and the right is from this NASA page. From the right image, it is clear that the dot in the middle is the rover itself, and the light patches to the upper right and lower left are probably where the rockets scoured away an upper darker level of soil. But what is the dark streak? And why are there two separate patches? With four rockets in a boxy rectangle 25 feet up, I would have expected a single oval scoured patch.

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    $\begingroup$ This are most likely the result of the skycrane rocket blast pushing the darker dirt together between them, but I have no documented source for that. $\endgroup$
    – GdD
    Commented Feb 27, 2021 at 22:08
  • $\begingroup$ @GdD I am sure you are right, see comment. These (PIA24334) are cropped from PIA24333 and this is from the monochrome Context Camera (CTX) not HiRise. CTX covers 500 to 800nm from green to near infrared, and so images will respond differently to the quantity and arrangement of fine martian dust particles than an image from HiRise would. $\endgroup$
    – uhoh
    Commented Feb 28, 2021 at 1:36

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The landing system jets are angled off to either side of the rover, resulting in the surface disturbance pattern you noticed.

enter image description here

From Mars Science Laboratory: Entry, Descent, and Landing System Performance, I added the red arrows.

This picture from Popular Science shows a more orthogonal view with the plumes from all 4 jets.

enter image description here

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    $\begingroup$ is it possible to address why the side lobes are brighter than average while at the same time the central strip which is parallel to the "fly off" direction is darker than average? I think that's the thrust of the question (pun intended). I think that this comment is on the right track; the central streak is a "piled higher and deeper" collection of regolith removed from the two side lobes; if less=brighter then more=darker. If it's removed from one place it has to end up somewhere else. But hmm... how to support... $\endgroup$
    – uhoh
    Commented Feb 28, 2021 at 1:26
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    $\begingroup$ Unfortunately the papers I read only showed the surface impingement patterns from a single jet. $\endgroup$ Commented Feb 28, 2021 at 1:33
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    $\begingroup$ It looks from the landing video as if the rockets are in two parallel pairs, two angling down and to the rover's left, and the other two angling down and to the rover's right. I think this is what you mean to convey, but it can't be unambiguously inferred from the diagram, which only shows the view from one angle. $\endgroup$ Commented Feb 28, 2021 at 4:20
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    $\begingroup$ @OrganicMarble I'm thinking that in the OP's photos the dark centerline between the two cleared spots is likely dark because it contains piled up regolith removed from the two white spots. Figure 11 also shows that in a CTX image regolith removed from an area and redeposited nearby is darker. This part: "The distribution of the dark rays, an indicator of the surface dust disruption, is asymmetric, implying that the impactor came in from the south‐southeast. While quite young..." seems to apply. $\endgroup$
    – uhoh
    Commented Mar 1, 2021 at 0:23
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    $\begingroup$ @OrganicMarble I'm not saying it's a slam-dunk nor that it rises to the level of an answer but it may help at some point. OP asks about three bright spots; two are likely cleared areas, the third is likely the reflective rover. OP also asks about the "dark streak" and that's where this may be helpful; if you have cleared areas, then you must also have redeposited areas, and the paper shows that a redeposited area from a "young area" can look dark in the CTX camera. $\endgroup$
    – uhoh
    Commented Mar 1, 2021 at 0:26

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