Zhurong maps, traverse route and location mapping Options

[Phil Stooke]

I'm starting a map thread. It's hard to know what we will get but I expect a route map will emerge bit by bit. Maps showing the landing location will be easier to make initially.

Phil

[Phil Stooke]

Starting off with an overview of the site, with landing ellipses based on the work done at Hong Kong Polytechnic University. The initial site is indicated. The landing ellipse is about 60 by 20 km and if you center one at the initial site it contains two craters with rough ejecta blankets (bright in this image, which is Mars Odyssey THEMIS infrared with inverted shading). Two nearby ellipses were chosen to avoid the craters, and the western one was then moved a bit to avoid more rough terrain at its southern end. The landing site is very close to the center of that ellipse and about 40 km from the initial site.

Phil

[Greenish]

Until higher-res imagery arrives, here's a crop at CTX full-res (5.67 m/px) with a circle roughly at the dot in Phil's ellipse map. (merge of 2 CTX tiffs - 1km squares for scale reference but not referring to any particular origin)

I think the distance from center to edge of the image, about 3.5km, is the horizon distance from about 1.7m height on Mars.

[Phil Stooke]

It's clear that following this mission will be tricky and maps will be tentative and only sporadically updated for a while.

But you have to start somewhere. This is a VERY tentative start. A HiRISE image will improve the basemap, and eventually a reprojected panorama can be laid over that.

What I show here is all I know at present. I will update it when we get news. Let me know if anything else appears! I am assuming landing day was sol 0 but that may not be correct.

Phil

[Phil Stooke]

OK, HiRISE image and a new location.

Phil

[Phil Stooke]

The text accompanying the 'group photo' of the rover and lander together says that the camera was deployed 10 m south of the lander. Then the rover moved back towards the lander for the photo. I have illustrated that here (using a guess as to the locations of the camera and the rover during photography). All very uncertain of course. I don't think the date of the group photo was mentioned - before or after the Tianwen-1 orbiter image, so I can't add a date.

All this is subject to ongoing revision.

Phil

[kymani76]

I'm a bit late to the game as I had other work, but it's finally time for me to catch up with all the events.


Revised landing ellipses map, with initial one in green and final one in yellow. Grid is at 10 km with smaller landing site quadrants at 1 km.

[kymani76]

All landed hardware map in HiRise color. Grid at 1km.

[kymani76]

Traverse map, based on tracks visible when enhancing HiRise image. Note the small area size of the map. I get 75m of distance from track in close aligment with reported 80m distance.
Grid at 10m.


Wider landing map in color, with engine exhaust obscuring the area of recent activity. Grid at 100m.

[Phil Stooke]

After the second HiRISE image appeared I have made some big changes to my map. I decided that the dark markings west of the bright streak are probably not tracks after all - especially if you overlay the two HiRISE images, which makes the tracks east of the streak easier to see and the others less distinct. I also changed my interpretation of the 'group photo' from the deployed camera. The foreground surface in that image is more red on the left side and middle, and darker and less red on the right. I was interpreting that as showing the surface from the west side of the streak but now I think it's from the east, and that seems to match the geometry of the lander better as well.

All that may still be wrong! A Chinese map would be very useful. Until we get one HiRISE may be our best guide.

Phil

[Phil Stooke]

Bit by bit a map takes shape. This uses the new panorama.

Phil

[Phil Stooke]

And an overview map - this will be the standard resolution for mapping.

Phil

[Huguet]

And Zhurong is almost at the parachute... Would be nice to get a new Hirise.

Huge image with a recent path nice guess from here:
https://twitter.com/TheElegant055/status/1413594702054674432
Link to 50MB full resolution version:
https://drive.google.com/drive/folders/19PT...TILuTgwRZE4Mk8E

Attached thumbnail(s)

 

[Bill Harris]

So, those light-toned features are barchan-like dunes. Wonder if we can determine the composition of these dunes? Or what the source of this material is?

--Bill

[Phil Stooke]

The LIBS instrument will give composition - they were within LIBS range.

There are dark dunes on Mars (e.g. Bagnold Dunes in Gale Crater) and bright features like this, usually called drifts or ripples. The dark features are made of basaltic sand and they can indeed by barchans - see also the Greeley Dune Field inside Endeavour crater. These brighter features are made of finer material, silt to dust sized particles. The reason the dark and light don't just mix to form mid-toned deposits is that the wind sorts particles by size. That finer material is probably mixed globally and doesn't tell much about local geology.

(Continue discussion in the other thread)

Here is a very rough update to the map using the new information. A new HiRISE image would be very useful! (or a Chinese map)

Phil