Zhurong Lander/Rover, Surface Operations at Utopia Planitia Options

[Antdoghalo]

Looks like an alligator mouth

[rlorenz]

....
Seems like ~14 360 mosaics over ~5 months were taken - with 3x1 mosaics for drive direction for a few steps in-between each 360

Attached - a bunch of them at ~1/3rd res -

These are fantastic, Doug! I love how one panorama has rover structure in the foreground, and on the horizon you can see the lander and the backshell. And that the near-lander one has the little selfiecam sitting on the ground between the tracks...

[Huguet]

It is interesting to compare first and last panoramas.
The ammount of dust on the solar array and mast is impressive.

Attached thumbnail(s)

 

[Bill Harris]

Huguet, if those three images are all, then that is not a great deal of dust. Pre-cleaning by dust devils, Spirit and Oppy could have more dust.
Wasn't Zurgong supposed to have a vibrating device in the solar panels to clear dust deposited?

[Phil Stooke]

A tilting device, I think. But it doesn't help if the dust accumulates during a winter shutdown and then the rover can't wake up to use the device.

Phil

[Quetzalcoatl]

Bonjour,

An in-situ observation made by Zhurtong would attest to the reality of a Martian paleo-ocean

https://academic.oup.com/nsr/advance-articl...482?login=false

https://phys.org/news/2023-05-in-situ-marin...t-northern.html

[serpens]

Thanks for the links. The sedimentary evidence is compelling and combined with all other evidence confirms the existence of the Northern basin ocean. The conflict between the faint young sun hypothesis, a warm wet early Mars and no compelling greenhouse gas explanation will continue to drive researches crazy.

[Phil Stooke]

I am working on the Tianwen-1/Zhurong section of my book, hoping to created an accurate map of the whole traverse. I think by now, a year without any movement of the rover, we can consider the surface mission over.

But trying to nail down which sol the rover was at each location is very difficult. Consider these two published maps:




The map on the left is from:

Ding, L., Zhou, R., Yu, T., Gao, H., Yang, H., Li, J., Yuan, Y., Liu, C., Wang, J., Zhao, Y.Y. and Wang, Z., 2022. Surface characteristics of the Zhurong Mars rover traverse at Utopia Planitia. Nature Geoscience, 15(3), pp.171-176. https://doi.org/10.1038/s41561-022-00905-6

The map on the right is from:

Chen, R., Zhang, L., Xu, Y., Liu, R., Bugiolacchi, R., Zhang, X., Chen, L., Zeng, Z. and Liu, C., 2023. Martian soil as revealed by ground-penetrating radar at the Tianwen-1 landing site. Geology, 51(3), pp.315-319. https://doi.org/10.1130/G50632.1


These are both good papers in top journals, but their maps do not agree.Look at the point labelled 59 on the left. It corresponds with the point labelled 60 on the right.

A one sol difference might be the result of starting the mission with landing on sol 0 or sol 1 in different sources, and there does seem to be confusion about that. In the early sols I thought the landing was on sol 0, but I don't recall where that came from. The Ding paper, which includes a table of activities for sols 1-60, uses sol 1, and I will be working with that now.

A one sol difference also might arise from the 'park, sleep, study, drive' sequence we see on NASA rovers. Curiosity, for instance, might drive and park for the night on sol 1000, make science observations on the next morning and then drive again, putting sol 1001 observations and target names at the sol 1000 location. All us poor rover mappers have had to deal with that.

But then look at the twisty bit of the path labelled 28-29-30 on the left. The corresponding points on the right are 30-31-33.

It is very unfortunate that the mission team have not released an official map so that everyone - Chinese scientists as well as everyone else - can work with the same data.

I am going to try some contacts in China.

Phil

[Bill Harris]

You've probably already tried this, but overlay the two maps, aligning on topo features, with the yracks in different colors or with clickable visibility, and try to sort things out.
The mission was quite impressive.

--Bill

[Phil Stooke]

No, that doesn't change things.

Long Xiao has told me that the answer is that Zhurong may spend 2 or 3 sols at one place making observations, and the differing dates in different papers are observation dates at that point. His recent paper on marine sediments also had dates which differ a bit from either of those sources I linked to. This helps, and I will try a canonical map giving what I think are actual dates at each location, but I think there are still going to be some discrepancies. More to come.

[tanjent]

Two general points, not necessarily enlightening in this particular case:

1. Are we sure that we are consistently measuring from the same point on the rover itself? The shorter the rover's track, the larger the contribution of the rover's own dimensions to the perceived wiggles as it rolls along. If each sol's position is based on photos taken from the lander, are we measuring the same spot on the rover, and taking account that the rover was likely not presenting the same profile to the camera each time? Even without movement to a new stopping point, the orientation may change based on the activities being performed. Of course for longer tracks like those of Spirit or Opportunity this issue would quickly fade to irrelevance.

2. Another possible source of confusion might be the calendar dates here on Earth. Is each stopping point stamped with a specific Mars time at which it was recorded? If not, then possibly there is some noise introduced translating back and forth between the Mars dates and the Earth dates. Since China is all on one time zone this seems unlikely, but on some occasions dates may have been adjusted for the convenience of researchers in different parts of the world. (It's always amusing when fortune tellers attach great significance to the time and date of one's birth but fail to adjust for the time zone one was born in. I would not expect this to pose an issue among scientists, but it is worth verifying that the sols and Mars times at each position are unaltered by translations to and from any other coordinate system.)

[Phil Stooke]

Good points but probably not what is needed here. Really we need a simple map showing the location of the rover on each sol of the mission, or a table of coordinates giving the same information. Since China has not given us one and the maps published in multiple sources do not agree with each other, we are struggling with much more basic issues.

I have made an effort to bring everything I have found into one set of locations, spread across 3 maps, and put them in the route map thread. Don't assume it is correct, but it is the best I can do at the moment.

Phil

[Phil Stooke]

I made some circular projections of Doug's panoramas while doing the mapping work.

Phil


(sol 32)


(sol 43)


(sol 59)


(sol 93)



(sol 101)

[Bill Harris]

Zhurong + ground penetrating radar + polygons in Nature.

https://www.nature.com/articles/s41550-023-02117-3.pdf

[Glevesque]

Constraints on water activity at the Zhurong landing site in Utopia Planitia, Mars, Mars mai 2023
https://www.researchgate.net/publication/37...a_Planitia_Mars