The purpose of the abrasion is to grind awway the outer rind of material on the surface of the rock. We do that because that outer "skin" has been eroded by sand, wind and even moisture for up to billions of years. Geologists would like to see the fresh, untouched interior of the rock, so Percy abrades the outer few millimetres. In the case of this abrasion, we got a truly glorious result in doing so.
I need to write up a FAQ for the whole process and science of abrasions that this rover makes, but I'm a little delayed right now by all the amazing stuff this mission keeps throwing at us...
I'm not sure. In the case of Perseverance, I know that they block out those goddamned instances when the sandworms photobomb the panoramas, but I don't blame JPL for that - those things are repulsive.
We do know that Curiosity has some overly aggressive tendencies when it comes to small furry mammals. I hope the rover AI hasn't gone on another rampage and tried to hide the evidence again. It takes months to remove the organic matter contamination from the instruments.
All of that being said, I can imagine that there could be some utility in operating a rover prototype in the lab or in a sandbox via a gaming device like this. It would have some advantages over a laptop, assuming the wireless connection is solid and latency is low.
Provided the Steam Deck is in the same room as the rover, not 200 million km away.
JPL actually released some of the software that they used to plan drives for Spirit and Opportunity, but they haven't done so for the current rover missions.
I would absolutely adore anything that simulates actually rover planning and driving.
It's not often that I downvote anything posted to this community, but I've done so here. A few notes of caution about this article are required:
It contains no mention whatsoever of Curiosity, Perseverance or any rover currently scheduled for launch to Mars, let alone one currently operating on the planet
The time delay for signals between Earth and Mars is currently ~17 minutes - that's one way - and is never less than ~4. I don't think thumbsticks, face buttons or a handheld screen are going to mitigate that. Your refresh rate is going to be just a bit short of 60 FPS. Unless the Steam Deck/tablet/PC can violate relativity.
Remotely operated ground vehicles on other planets (with the possible exception of Luna) are semi-autonomous, in the sense that they drive themselves to locations that the scientists direct them to. Geologists choose a point in the landscape where they want to the rover to go, then the rover chooses a path through the landscape via image analysis. Rover "drivers" (AKA Rover Planners) can issue a "directed drive" command, i.e. manually pre-planning the route, but the autonomous capability ("AutoNav") is commonly used for longer drives.
We are not in continuous communication with any Mars rover, lander or orbiter. Interplanetary communication for landed vehicles works like this: Rover uploads to Mars-orbiting satellite, via its weak transmitter --> Mars-orbiting satellite transmits to Earth, via its stronger transmitter --> Absurdly powerful ground-based receiver on Earth captures signal --> Data packet from rover is transmitted to control center. In the case of uploading commands, the sequence is reversed. Please note that all of this requires the satellite at Mars to actually pass over the rover's location, preferably directly overhead (not always the case). This entire sequence can happen, at most, a few times a day, but generally it happens once or twice.
Using handheld devices to plan the rover's route (in the case of the engineers) or review the rover's data and photos (in the case of the scientists) makes little sense. Larger displays are clearly better for this task, where mapping and visualization are essential. The complex software suites that the engineers use to plan the rover's drives aren't going to be better suited to a video game controller than they are to a mouse and keyboard.
In short, the suggestion that a handheld gaming device would be used for operating a currently active spacecraft, lander or rover is absurd.
Date: Sol 1931 (Ls 325º, Year 38) / (26 July 2026) Campaign: Crater Rim (33rd abrasion) Location: Nili Planum/Lac de Charmes Elevation: 1959 metres below datum Map Quadrangle: Forêts RMC Site: 89_4246 Site Arrival: Sol 1927 Site Departure: Sol 1935
Date: Sol 1914 (Ls 315º, Year 38) / (9 July 2026) Campaign: Crater Rim (32nd abrasion) Location: Nili Planum/Lac de Charmes Elevation: 1973 metres below datum Map Quadrangle: Forêts RMC Site: 89_2556 Site Arrival: Sol 1913 Site Departure: Sol 1917
I like your way of thinking here. I'm honestly not sure if the actual geologists working on lunar soil simulants today are more hardcore than Kubrick was back then.
With all the cuts to NASA and the American scientific enterprise generally, we could use this kind of angel perfectionist director these days. I wonder if Denis Villeneuve could be convinced to forget about Arrakis for a while and work closer to home...
I don't know if Prof. Ruff (Mars Guy) writes the headlines himself, and he was quite upbeat about the coating itself, but -
I've seen people laugh at geologists, who complain about Earth's abundant vegetation getting in the way of access to the rocks. I don't think we're allowed to complain about rock coatings, which really do say a lot...
This is a very good explanation, and I would assume you're correct!
I would love to know if the exposed ribbon cable which I apparently mistook for a coating has any of the shallow grooves apparent in your image. I don't see evidence of any in the MastCam image which started all this.
I would, however, seriously like to know why they manufacture those ribbon cables in that particular hue.... All of this would explain why I've struggled to find any further evidence of "purple coatings" elsewhere on the rover deck.
Anyhow, I think Paul's engineering-oriented insight prevails over my weekend-long, productivity-killing literature review and general rabbit hole-oriented science head...
I have struggled to find earlier MastCam images of this difficult-to-reach part of Percy, but I will post updates if I find any. The science team doesn't image this part of the rover deck very often - at least not of late:
This location at the base of the rover's "neck" (mast) appears partly sheltered from the wind, which is interesting.
I'd be rather surprised if this is a meteorite, especially an iron meteorite. I'm not seeing enough in terms of regmaglypts or any of the usual telltales (e.g. Widmanstätten).
Could this be a stony meteorite? I can't bring myself to see a fusion crust here in any wise. There are no flow lines that I can identify. The sharp, small protuberances at the bottom right would also be very unusual for a meteorite in my experience.
Of course, I could be wrong, but it doesn't resemble any that I've seen. The science team doesn't seem to be showing much interest in this one; and I would swear I've seen similar rocks on this mission, but none are coming to mind at the moment. I'll see if I can scare up anything similar...
Thanks for this post. People don't understand about geology and context, I find. I would love to see more of your commentary in the Perseverance rover and Curiosity rover communities, although I do remember seeing you there in the past. My mineralogy is still rather basic, all told, and with the exotic lithologies Perseverance is uncovering (well, by Martian standards - granite and serpentine, yet!), your participation would be most welcome.
Date: Sol 1885 (Ls 298º, Year 38) / (9 June 2026) Campaign: Crater Rim (31st abrasion) Location: Nili Planum/Lac de Charmes Elevation: 1952 metres below datum Map Quadrangle: Forêts RMC Site: 88_1722 Site Arrival: Sol 1883 Site Departure: Sol 1890
Date: Sol 1870 (Ls 289º, Year 38) / (25 May 2026) Campaign: Crater Rim (30th abrasion) Location: Nili Planum/Lac de Charmes Elevation: 1958 metres below datum Map Quadrangle: Forêts RMC Site: 88_1214 Site Arrival: Sol 1867 Site Departure: Sol 1877
Date: Sol 1851 (Ls 277º, Year 38) / (5 May 2026) Campaign: Crater Rim (29th abrasion) Location: Nili Planum/Lac de Charmes Elevation: 1974 metres below datum Map Quadrangle: Forêts RMC Site: 88_206 Site Arrival: Sol 1842 Site Departure: Sol 1849
Date: Sol 1844 (Ls 272º, Year 38) / (28 April 2026) Campaign: Crater Rim (28th abrasion) Location: Nili Planum/Lac de Charmes Elevation: 1968 metres below datum Map Quadrangle: Forêts RMC Site: 88_0 Site Arrival: Sol 1842 Site Departure: Sol 1849
Date: Sol 1821 (Ls 257º, Year 38) / (4 April 2026) Campaign: Crater Rim (27th abrasion) Location: Nili Planum/Lac de Charmes Elevation: 1978 metres below datum Map Quadrangle: Forêts RMC Site: 87_4084 Site Arrival: Sol 1819 Site Departure: Sol 1825
Date: Sol 1794 (Ls 240º, Year 38) / (8 March 2026) Campaign: Crater Rim (26th abrasion) Location: Nili Planum/Lac de Charmes Elevation: 1958 metres below datum Map Quadrangle: Kruger RMC Site: 87_0 Site Arrival: Sol 1792 Site Departure: Sol 1805
I'm sensing jest here, but for those not in the know, the rover makes these patches with its Rock Abrasion Tool:
https://www.youtube.com/watch?v=INlSAGD01q8
The purpose of the abrasion is to grind awway the outer rind of material on the surface of the rock. We do that because that outer "skin" has been eroded by sand, wind and even moisture for up to billions of years. Geologists would like to see the fresh, untouched interior of the rock, so Percy abrades the outer few millimetres. In the case of this abrasion, we got a truly glorious result in doing so.
I need to write up a FAQ for the whole process and science of abrasions that this rover makes, but I'm a little delayed right now by all the amazing stuff this mission keeps throwing at us...
I'm not sure. In the case of Perseverance, I know that they block out those goddamned instances when the sandworms photobomb the panoramas, but I don't blame JPL for that - those things are repulsive.
We do know that Curiosity has some overly aggressive tendencies when it comes to small furry mammals. I hope the rover AI hasn't gone on another rampage and tried to hide the evidence again. It takes months to remove the organic matter contamination from the instruments.
All of that being said, I can imagine that there could be some utility in operating a rover prototype in the lab or in a sandbox via a gaming device like this. It would have some advantages over a laptop, assuming the wireless connection is solid and latency is low.
Provided the Steam Deck is in the same room as the rover, not 200 million km away.
JPL actually released some of the software that they used to plan drives for Spirit and Opportunity, but they haven't done so for the current rover missions.
I would absolutely adore anything that simulates actually rover planning and driving.
It's not often that I downvote anything posted to this community, but I've done so here. A few notes of caution about this article are required:
In short, the suggestion that a handheld gaming device would be used for operating a currently active spacecraft, lander or rover is absurd.
Abrasion date and location
Date: Sol 1931 (L
s325º, Year 38) / (26 July 2026)Campaign: Crater Rim (33rd abrasion)
Location: Nili Planum/Lac de Charmes
Elevation: 1959 metres below datum
Map Quadrangle: Forêts
RMC Site: 89_4246
Site Arrival: Sol 1927
Site Departure: Sol 1935
Associated samples
None
Geology
Mapped unit:
Formation: Undefined
Rock Type:
Interpretation:
Chisel marks: Yes (prominent)
Mission analysis
Blog entries: None
Depth of abrasion: ?
Night-time LED images: Sols
Flourescent images: Sol
Abrasion animation: Yes
PIXL images:
SuperCam images:
Abrasion date and location
Date: Sol 1914 (L
s315º, Year 38) / (9 July 2026)Campaign: Crater Rim (32nd abrasion)
Location: Nili Planum/Lac de Charmes
Elevation: 1973 metres below datum
Map Quadrangle: Forêts
RMC Site: 89_2556
Site Arrival: Sol 1913
Site Departure: Sol 1917
Associated samples
None
Geology
Mapped unit:
Formation: Undefined
Rock Type:
Interpretation:
Chisel marks: Yes (prominent)
Mission analysis
Blog entries: None
Depth of abrasion: ?
Night-time LED images: Sols
Flourescent images: Sol
Abrasion animation: Yes
PIXL images:
SuperCam images:
It won't, certainly not directly. It would help individual scientists if they can land funding from non-governmental sources, though.
I like your way of thinking here. I'm honestly not sure if the actual geologists working on lunar soil simulants today are more hardcore than Kubrick was back then.
With all the cuts to NASA and the American scientific enterprise generally, we could use this kind of angel perfectionist director these days. I wonder if Denis Villeneuve could be convinced to forget about Arrakis for a while and work closer to home...
I don't know if Prof. Ruff (Mars Guy) writes the headlines himself, and he was quite upbeat about the coating itself, but -
I've seen people laugh at geologists, who complain about Earth's abundant vegetation getting in the way of access to the rocks. I don't think we're allowed to complain about rock coatings, which really do say a lot...
This is a very good explanation, and I would assume you're correct!
I would love to know if the exposed ribbon cable which I apparently mistook for a coating has any of the shallow grooves apparent in your image. I don't see evidence of any in the MastCam image which started all this.
I would, however, seriously like to know why they manufacture those ribbon cables in that particular hue.... All of this would explain why I've struggled to find any further evidence of "purple coatings" elsewhere on the rover deck.
Anyhow, I think Paul's engineering-oriented insight prevails over my weekend-long, productivity-killing literature review and general rabbit hole-oriented science head...
Some notes --
I have struggled to find earlier MastCam images of this difficult-to-reach part of Percy, but I will post updates if I find any. The science team doesn't image this part of the rover deck very often - at least not of late:
This location at the base of the rover's "neck" (mast) appears partly sheltered from the wind, which is interesting.
Image sources:
Abrasion patch #2
Abrasion patch #18
"Bizarre" purple coating (left)
"Bizarre" purple coating (right)
I'd be rather surprised if this is a meteorite, especially an iron meteorite. I'm not seeing enough in terms of regmaglypts or any of the usual telltales (e.g. Widmanstätten).
Could this be a stony meteorite? I can't bring myself to see a fusion crust here in any wise. There are no flow lines that I can identify. The sharp, small protuberances at the bottom right would also be very unusual for a meteorite in my experience.
Of course, I could be wrong, but it doesn't resemble any that I've seen. The science team doesn't seem to be showing much interest in this one; and I would swear I've seen similar rocks on this mission, but none are coming to mind at the moment. I'll see if I can scare up anything similar...
Thanks for this post. People don't understand about geology and context, I find. I would love to see more of your commentary in the Perseverance rover and Curiosity rover communities, although I do remember seeing you there in the past. My mineralogy is still rather basic, all told, and with the exotic lithologies Perseverance is uncovering (well, by Martian standards - granite and serpentine, yet!), your participation would be most welcome.
Abrasion date and location
Date: Sol 1885 (L
s298º, Year 38) / (9 June 2026)Campaign: Crater Rim (31st abrasion)
Location: Nili Planum/Lac de Charmes
Elevation: 1952 metres below datum
Map Quadrangle: Forêts
RMC Site: 88_1722
Site Arrival: Sol 1883
Site Departure: Sol 1890
Associated samples
None
Geology
Mapped unit:
Formation: Undefined
Rock Type:
Interpretation:
Chisel marks: Yes (prominent)
Mission analysis
Blog entries: None
Depth of abrasion: ?
Night-time LED images: Sols
Flourescent images: Sol
Abrasion animation: Yes
PIXL images:
SuperCam images:
Abrasion date and location
Date: Sol 1870 (L
s289º, Year 38) / (25 May 2026)Campaign: Crater Rim (30th abrasion)
Location: Nili Planum/Lac de Charmes
Elevation: 1958 metres below datum
Map Quadrangle: Forêts
RMC Site: 88_1214
Site Arrival: Sol 1867
Site Departure: Sol 1877
Associated samples
None
Geology
Mapped unit:
Formation: Undefined
Rock Type:
Interpretation:
Chisel marks: Yes (prominent)
Mission analysis
Blog entries: None
Depth of abrasion: ?
Night-time LED images: Sols
Flourescent images: Sol
Abrasion animation: Yes
PIXL images:
SuperCam images:
Abrasion date and location
Date: Sol 1851 (L
s277º, Year 38) / (5 May 2026)Campaign: Crater Rim (29th abrasion)
Location: Nili Planum/Lac de Charmes
Elevation: 1974 metres below datum
Map Quadrangle: Forêts
RMC Site: 88_206
Site Arrival: Sol 1842
Site Departure: Sol 1849
Associated samples
None
Geology
Mapped unit:
Formation: Undefined
Rock Type:
Interpretation:
Chisel marks: Yes (prominent)
Mission analysis
Blog entries: None
Depth of abrasion: ?
Night-time LED images: Sols
Flourescent images: Sol
Abrasion animation: Yes
PIXL images:
SuperCam images:
Abrasion date and location
Date: Sol 1844 (L
s272º, Year 38) / (28 April 2026)Campaign: Crater Rim (28th abrasion)
Location: Nili Planum/Lac de Charmes
Elevation: 1968 metres below datum
Map Quadrangle: Forêts
RMC Site: 88_0
Site Arrival: Sol 1842
Site Departure: Sol 1849
Associated samples
None
Geology
Mapped unit:
Formation: Undefined
Rock Type:
Interpretation:
Chisel marks: Yes (prominent)
Mission analysis
Blog entries: None
Depth of abrasion: ?
Night-time LED images: Sols
Flourescent images: Sol
Abrasion animation: Yes
PIXL images:
SuperCam images:
Abrasion date and location
Date: Sol 1821 (L
s257º, Year 38) / (4 April 2026)Campaign: Crater Rim (27th abrasion)
Location: Nili Planum/Lac de Charmes
Elevation: 1978 metres below datum
Map Quadrangle: Forêts
RMC Site: 87_4084
Site Arrival: Sol 1819
Site Departure: Sol 1825
Associated samples
None
Geology
Mapped unit:
Formation: Undefined
Rock Type:
Interpretation:
Chisel marks: Yes (prominent)
Mission analysis
Blog entries: None
Depth of abrasion: ?
Night-time LED images: Sols
Flourescent images: Sol
Abrasion animation: Yes
PIXL images:
SuperCam images:
Abrasion date and location
Date: Sol 1794 (L
s240º, Year 38) / (8 March 2026)Campaign: Crater Rim (26th abrasion)
Location: Nili Planum/Lac de Charmes
Elevation: 1958 metres below datum
Map Quadrangle: Kruger
RMC Site: 87_0
Site Arrival: Sol 1792
Site Departure: Sol 1805
Associated samples
None
Geology
Mapped unit:
Formation: Undefined
Rock Type:
Interpretation:
Chisel marks: Yes (prominent)
Mission analysis
Blog entries: None
Depth of abrasion: ?
Night-time LED images: Sols
Flourescent images: Sol
Abrasion animation: Yes
PIXL images:
SuperCam images: