• 23 Posts
  • 77 Comments
Joined 1 year ago
cake
Cake day: February 3rd, 2024

help-circle



  • 😃 Yes, these comparisons are pretty illuminating. I feel like the rover wheels really tell the tale here. If you squint hard enough, Curiosity is almost like Spirit - it faces rougher terrain than its “twin”, and has faced more adversity. Mt. Sharp/Aeolis is pretty unique geologically, and the place is just so mountainous, that the ripped-up wheels seem justified, somehow. Percy is kind of like “Oppy”, the golden child that was sent to a more benign environment, and literally bounced onto on the very thing we had dreamed of finding. Sample acquisition problems aside, Jezero Crater has been pretty good to us, as you can see from those very healthy wheels that Percy’s still sporting. I’d say Curiosity has fully earned those extra 30 metres 😁


  • Ah hahahahahahahahaah

    • We have 3rd-gen satellites that can correctly identify minerals from orbit, hundreds of kilometres away
    • We launch a huge, complex lander with an outstanding geology toolset, far better than the Apollo generation could have dreamed of
    • We send this technological marvel to a dry, eroded, pockmarked river delta billions of years old
    • The sampling system flawlessly acquires samples of “weak”, sometimes heavily-altered rocks that started off as loose sand, some even containing clay
    • We can plan the vehicle’s traverse so accurately that rover drivers can take weekends off without killing productivity

    … and even now, years after landing, this planet still throws us!

    I’m not even mad. I’m fascinated. The most difficult samples to acquire, our biggest “failures”, have been found at the literal lowest and highest elevations the rover has reached. Seriously, this apparent failure on 1409 has happened at a site almost 800 metres above the crater floor Percy first sampled in 2021. And both of these “problem” sampling sites clearly read as volcanic rocks… stuff that you’d think would be much easier to collect than old river sediment.

    Oh yes, this is Mars.


  • For reference, we are within sight of the patch abraded on sol 1360 (abrasion patch #32), the first Percy made on this side the rim.

    Being near the rim crest, #32 is the highest-elevation hole we’ve made, and will probably remain so, at least for a long while. As the highest bedrock layer on Witch Hazel Hill, it has something to say about the formation of Jezero, long before Neretva Vallis ever formed. 32 looks markedly different from the other three we’ve made on the hill, with all the well-defined brown grains on the right side and “fuzzy” whitish material in the middle. It looks quite different even from the two that are only slightly lower in elevation (famously crumbly #33 and the uniform-looking #35), only ~150 m away. It’s not entirely surprising to see the variety on display among the different patches we’ve sampled, but it is super neat to see the geologic diversity that this one hillside has to offer, considering that we haven’t even seen half of it yet!




  • I haven’t read the entire paper yet, but these bits in the intro caught my eye:

    the Ingenuity helicopter carries no scientific instrumentation, has a mass of less than 2 kg, and can only fly a few hundred meters at a stretch. Better-equipped aircraft may be possible on Mars, but even with a specialized entry-descent-and-landing approach to maximize the feasible payload, Mars rotorcraft will likely be limited to only a few kilograms, in part due to limitations of motor cooling in the thin Mars atmosphere.

    These limitations for Mars aerial exploration mean that any way to reduce payload without reducing scientific output would be advantageous, and one obvious avenue is using the drone itself as an environmental probe. Motivated by these considerations, B. Jackson recently explored using a drone to measure the near-surface wind profile, i.e., wind speed as a function of altitude. As a proof of concept, this effort followed on considerable previous work that showed that the tilt of a stably hovering drone can scale with wind speed—since a rotorcraft generates forward thrust, in part, by tilting into the thrust direction, the rotorcraft would have to tilt more into a stronger headwind. Drone attitude, including yaw, pitch, and roll, must be recorded for successful navigation on Mars anyway, so these data could be a way of retrieving the near-surface wind vector without requiring additional instrumentation.

    EDITED TO ADD: the paper surprisingly doesn’t mention dust devils, which would be a very exciting and important avenue of research for a drone. Long live Ingenuity!



  • Well, the atmosphere types aren’t going to be unhappy with this sample, anyway. I understand they had already collected the minimum mass that was specified pre-launch, but I was sure the mission would collect more, and I can’t blame the atmosphere people for asking. So I suppose having more “headspace” in this sample tube is OK.

    Assuming, though, that Steve Ruff (Mars Guy) is correct about this material being created or modified by the original Jezero impact event - I wonder if this much rock sample will be enough. The very thing that makes impact breccia/melt/glass so exotic and sexy is the same thing that makes it difficult to contextualize, i.e. the stuff is a mess! It could be a big grab bag of materials from different sources, and this site is already on the edge of Nili Planum, purportedly one of the oldest surfaces on Mars.

    On the other hand… if this stuff allows us to get a firm date on the Jezero impact itself… yeah, it would definitely be worth it.




  • This is one of the best dust devil videos ever captured, IMO. Spirit used to catch whole packs of them roaming the great prairie-like floor of Gusev Crater (back when that rover was perched up in the Columbia Hills, I believe), but this devil in the foreground here shows a lot of detail, and is quite close to the camera, unlike those in old shots from Spirit. From what I recall, Percy has been able to capture some nearby dust devils in similar detail, which is unsurprising given that the Jezero region is supposed to be the windiest site we’ve visited on Mars… but awesome nonetheless.

    Just looking at the shadows it casts is very revealing, and watching the thick white patches of the vortex really gives you an idea of the turbulence involved here. It’s really cool that we can see the entire length of the shadows being cast; I wonder if this is one reason why these shots were taken near noon, rather than later in the afternoon, around the time of maximum daily heating.

    For scale, the crater at the bottom left is 300 m across from left to right, so you can tell that the “foot” of the foreground devil is quite a bit bigger than Percy itself. So much to see here!



  • Hahaha I hear you, Paul. In the end, I’m just going to have to bite the bullet and learn how to work with images myself. I didn’t mean to put everything off onto you 😄

    As for people not appreciating the images, or the general stream of information from the rover(s), I’m proceeding on the theory that it’s hard to appreciate what these missions do without the context being readily available. Even in sifting through aaaall the images I needed to assemble my overview of the abrasion patches, I could see that I needed to rapidly compare and contrast several different abrasion sites to get a quick visual feel for the differences between them. And if someone like me feels this way, I can only imagine how difficult it might be for the casual social media user to see how exciting “another red rock” might be. Geologists aren’t always the best at outreach, but I believe the attempt is worth it in my case.

    I can’t help with the 3D images just yet, but I’ll see what I can do after I post my overview.





  • Younger (stupider) me thought that geotechnical engineering was boring and tedious, but as time goes on, and I see how much trouble it is to drill and collect samples from places like Mars, Luna, or the asteroids, I admit I’m changing my mind here. Between InSight’s troubles with the mole burrowing into that clumpy regolith in Elysium and the crumbly stuff Percy has to deal with, I’m realizing that we need some bright people to address these unexpected material properties with good hardware. I’ll add “sampling engineers” to the list of unsung heroes I’d love to hear more from, like the people behind Ingenuity!