The Top of Vera Rubin Ridge Part 2, Site 67-73, sol 1944-2297, 24 Jan 2018-22 Jan 2019 Options

[Gerald]

IIRC, the drill is designed to efficiently chip and remove rock, not grind it into fine dust.

The CheMin instrument requires powdered samples:

The sample introduced into the funnel consists of <= 65 mm^3 of powdered material with a grain size of <150 µm.

The drill is designed to deliver samples with a sufficient portion of the required range of grain sizes.

But you might be right, that some kind of silt stone with hematite as siltgrain-sized clusts instead of matrix material could be conceivable. (Although I'm unaware of an according example)
So, let's see, whether MAHLI can give us a hint towards the grain size of the drilled rock.
The remaining question would then be, whether hematite grains small enough to escape MAHLI's resolution can still be light grey instead of dark red.
(APXS can't distinguish unambiguously between hematite-bearing silicate rock and clay minerals of high iron abundance like nontronite, but CheMin can.)

[jvandriel]

Sol 2224 FrontHazcam Drilling Animation.

Jan van Driel

[fredk]

I've compared the color of the drill tailings in Paul's Sol 2224 MR image with early drill tailings taken by MAHLI

Apart from different cameras as you pointed out, tau can also have a large effect on the uncalibrated colours, as we've seen recently with the dust storm. Higher tau gives relatively more scattered light from the sky, and hence redder colours. Even at fixed tau the elevation of the sun will effect the colours.

[serpens]

If hematite formation was a late event (during the net erosion rather than deposition period) then different permeability of the rock or buffering effects of variable mineralogy could result in patchy oxidation to the ferric state. At low pH the reaction is very slow and and as a very rough rule of thumb a pH rise of 1 requires 100 times more oxygen availability.




.

[Phil Stooke]

This is Jan's panorama for sol 2222 in circular format.

Phil

[jvandriel]

Curiosity spotted a windgust on Sol 2230

Jan van Driel

[fredk]

Animation of the differences between the full set of 30 2230 frames and their average:

[paraisosdelsiste...]

Sunset on 14th was pretty beautiful...

[PaulH51]

Processed flicker GIF using two RMI frames from Sol 2232. Looks like a strong candidate for another iron meteorite judging by the external texture and the bright spots at the LIBS sites.

The mission update refers to this target as 'possible meteorite Little Todday'.

EDIT 2 : Sol 2231 R-MastCam (raw) and the 2232 with LIBS scars

[PaulH51]

4 overlapping ChemCam RMI's from sol 2232, roughly stitched in MS ICE.
Also another candidate iron meteorite zapped on sol 2233, estimated size using AlgorimancerPG

[neo56]

Nice sunset also on November 17th, aka sol 2233:

[fredk]

Some DD action from 2228:


And we are seeing some subtle clouds drifting by in some of the navcam sequences, eg:

[PaulH51]

Some DD action from 2228:
And we are seeing some subtle clouds drifting by in some of the navcam sequences, eg:

Nice spot, and those winds are continuing to move the cuttings (tailings) away from the recent drill hole as seen in this R-MastCam from 2238.

[SteveM]

Some DD action from 2228:

Nice image of the Dust Devils. I imagine you're taking the difference from the average, which for only three images produces unpleasant artifacts from the other two images. Why not take a median image as your basis — analogous to astronomical flat fields?

[Phil Stooke]

Here is a dust devil from sol 2238. In my version, I take the difference between two successive images. The top section is one of the images. The bottom is the difference between the two frames, enormously contrast-stretched. In the middle I superimpose the bottom over the top image to help locate it.

Phil