A SHERLOC WATSON and NavCam image of the latest abrasion patch acquired on sol 1375 (January 1, 2025).

The patch has a diameter of roughly 2 inches (5cm). The close up from the SHERLOC WATSON image shows the rough granular texture of the abraded surface.

Image credits: NASA/JPL-Caltech

  • SpecialSetOfSieves@lemmy.worldEnglish
    3·
    4 days ago

    Well well, this one is certainly different from the last few around the rim interior! This stuff doesn’t seem like a good candidate for coring, given the evident weakness/crumbliness.

    When looking at some of the LED-lit night-time imagery of this new one, I was immediately reminded of the sandstone/conglomerate-type rocks we analyzed down on the delta fan (Ouzel Falls and Thunderbolt Peak), but those were evidently more “solid” in bulk, despite their “messy”, pebbly appearance (or so I considered them at the time!)

    The friability of this latest one is pretty unprecedented - we’ve definitely seen prior examples of targeted rock breaking under the abrasion bit, but in a much cleaner way (Malgosa Crest, taken on the edge of Neretva Vallis, was the last one to do this, but that one has distinct vugs, and was definitely a harder material; Elkwallow Gap, from the delta front/“bacon strip” region, was surprisingly weak, but broke clean in two - and that only after digging into the rock a fair distance, it seems).

    I find it particularly interesting that the points where the rock is most brittle/cracked align very neatly with darkest material in the patch… and there is quite a bit more to see here besides. This mission is just so much fun. Happy terrestrial New Year!

    • paulhammond5155@lemmy.worldOPEnglish
      3·
      4 days ago

      Agreed fully regarding being a poor candidate for coring.

      The night shots were not down when I posted the other images, the colours under the white LEDs are interesting :) I wish they would take more at night with those white LED, not just cored holes and abrasions :)

      My brain refused to recall ‘Friability’ when I made the post… LOL

      What vistas and rock types await… It’s going to be a fun year ahead :)

    • SpecialSetOfSieves@lemmy.worldEnglish
      3·
      4 days ago

      Geologist lingo:

      • Coring - Drilling in order to acquire a “core sample”, in this case for return to Earth (hopefully). Often proves difficult, on every planet we’ve tried it.
      • Conglomerate - Sedimentary rock that contains rounded pebbles surrounded by finer-grained stuff (e.g. mud, sand), like raisins sprinkled in dough. Not surprising to find these where a river flowed, naturally.
      • Delta fan - the flattish “platform” of sediment dumped by a river entering a larger, calmer body of water.
      • Vug - Small cavity inside a rock, as distinct from a mineral vein (which are long, narrow, and filled in). Can be created by a variety of causes. Sometimes filled in later, by agents such as flowing groundwater.