Some further navigation info for context here. Updated map of Percy’s immediate whereabouts below (with recent abrasion, #44, marked):
For a broader view of Percy’s activities since crossing over to the exterior of the Jezero rim, please see this rudimentary guide (sorry, it’s a work in progress).
Judging from the last two weeks of short drives up the current slope (zoom in on the map above to see what I mean), it would appear that the science team is very carefully documenting the different outcrops/rock types we can see around here.
I’ve only noticed this level of interest concentrated in one small area twice before this year, in two spots further north (Witch Hazel hill), where the rover acquired quite a few samples. Based on the topography, I’m speculating that this layer/set of strata wasn’t exposed further north. No geologist likes a gap in their wedding cake, of course - and that’s even before you consider that the rim of this crater is not recording a gently-deposited set of flat layers, but a wild sequence of different rocks, altered in different ways, and quite possibly at different times. So what we’ve found on the rim already demands we be complete with our investigation; OTOH, it may be that they’ve spotted something interesting in the mineralogy here that warrants this kind of careful mapping.
There is a basic question to be asked here: how much of the these flattish rocks we find on the slope are basically volcanic in origin (as Mars Guy would only be too happy to tell you about), and how much is due to the mind-bending, one-and-done violence of the original Jezero impact, which punched out a basin 50 km across and half a kilometre deep (at the very least)? Though Curiosity has been climbing its mountain for many years, Percy has experienced an elevation change almost as great in its much shorter mission, simply by driving out of the crater and onto the Nili plateau - and Jezero is a fairly modest-sized crater by Martian standards.
When you consider that this landscape might preserve evidence of a much larger impact found far downriver from Jezero (the one that made the Isidis basin, a mere 1500 km across), not to mention the immense age of the Nili countryside, which still shows traces of eruptions originating far underground, the question of “impact vs. volcanism” no longer seems like a small question, but a global one.
I feel small now.
