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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.

Mark Foskey
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    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. – GdD Feb 27 '21 at 22:08
  • @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. – uhoh Feb 28 '21 at 01:36

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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

Organic Marble
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    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... – uhoh Feb 28 '21 at 01:26
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    Unfortunately the papers I read only showed the surface impingement patterns from a single jet. – Organic Marble Feb 28 '21 at 01:33
  • See Figure 11 and caption, and also the last paragraph of section 2.9.1 (paragraph [54]) of Context Camera Investigation on board the Mars Reconnaissance Orbiter I think it can be sufficient. Noted here that this is the Context Camera (CTX) and not HiRise. – uhoh Feb 28 '21 at 01:45
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    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. – Mark Foskey Feb 28 '21 at 04:20
  • @uhoh I looked at that paper and it's over my head to see what Figure 11 has to do with this question. But IANA geologist. I was looking for a prediction of the plume/surface interaction for the pattern of all 4 jets. – Organic Marble Feb 28 '21 at 16:07
  • @MarkFoskey added a picture showing all 4 jets. – Organic Marble Feb 28 '21 at 16:12
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    @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. – uhoh Mar 01 '21 at 00:23
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    @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. – uhoh Mar 01 '21 at 00:26
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    @uhoh thanks, I understand now. I'm gonna continue my quest for the plume/surface interaction graphic. – Organic Marble Mar 01 '21 at 01:13