If I ever meet someone who says planning traverses on the Moon, or any planetary body for that matter,was easy then I will laugh out loud. Numerous steps need to be taken when planning a traverse for rovers and human crewed missions. Incorporation of several remote sensing datasets is vital, and you need to have a clear understanding of the surface processes and the diverse lithologies of the Moon. I am mentioning all of this because I have spent the past week with my graduate internship team compiling and interpreting Lunar Reconnaissance Orbiter (LRO) Narrow Angle Camera (NAC) images, Vis-IR and UV data from Clementine, spectral profiles (resolution per pixel: 562 x 400 m) from SELENE, reflectance spectra from the Moon Mineralogy Mapper (M3), and robotic traverses proposed by Steenstra et al. (2016). It has been a long week, and staring at computer screens for hours looking for outcrops, boulder and boulder tracks, and "fresh" impact craters does strain your eyes. If any of you can remember a previous blog I posted I discussed the use of ISIS3 cube files and image processing. The basic skills I picked up teaching myself ISIS image processing has really come in handy for this internship, although my current roommate,Valentin Bickel's skills using ISIS3 are a lot more developed and refined than my own. He has helped me write a script for calibrating and projecting LRO NAC images.
Image of Schrodinger Basin taken by the Clementine spacecraft. Red box highlights our general study area at Schrodinger.
Until I know how much I am allowed to tell you about our projects here at LPI, I will give you a brief overview. We have been looking at the SW portion of the peak-ring structure in Schrodinger Basin to determine whether we should plan another robotic traverse to answer more science goals announced by the National Research Council (NRC) in 2007, or create a detailed geological map using a variety of remote sensing datasets. We are currently at the stage of selecting sample stations around the SW peak-ring structure. Stations will first be chosen based off LRO NAC images. Next, we will remove stations that are on slopes greater than 16 degrees because it is the maximum slope a lunar rover can climb according to the specifications reported by Steenstra et al. (2016). The NRC science goals we plan to expand on are, investigating the structure of peak rings in impact basins, constraining the impact cataclysm that occurred approximately 4 to 4.1 billion years ago, and create a stratigraphy of the lunar farside crust by analysing the peak ring material (troctolite, norite, pyroxene-anorthosite, and anorthosite).
Our second project is calculating the trafficability of pyroclastic material and regolith in Permanently Shadowed Regions (PSR) on the Moon. When planning a rover traverse, we need to know what the maximum speed of the rover will be on the surface, which will change depending on the physical properties of the regolith. Pyroclastics are an important science target for understanding the internal heat engine (heat distribution in the lunar crust and mantle) of the Moon, and for in situ resource utilization (ISRU). Landers, rovers, and eventually human crews will be sent to sites with pyroclastic deposits. By calculating the trafficability of the material we will know how traversable the surface will be for rovers. PSRs are hot spots for volatiles (get it, its ironic because volatiles prefer cold environments...), but little is known about the physical properties of regolith in these regions. Sending a rover into a PSR would fix this, however there is concern about sending a rover into a PSR when little is known about its surface environment and rock abundance.
Now calculating the trafficability of pyroclastics and PSRs (especially PSRs!) is challenging when you only have access to remote sensing datasets and a limited selection of Apollo data. What we have to do is look for areas in pyroclastic deposits and PSRs where the regolith has been disturbed. One feature that disturbs the regolith on the Moon are boulders, which leave tracks when they fall down slopes and impact basin peak rings. The team is currently running calculations on ArcGIS, so we will soon know the trafficabiltiy of pyroclastic material and regolith in PSRs.
I was going to talk about the calculations but that will require another blog post. I will be posting more about this next week when I have more information to share with all of you.
Sorry this weeks blog is short, next weeks will be longer! See you all soon.