Written by Lucy Lim, a planetary scientist at NASA's Goddard Space Flight Center

Earth Plan Date: Monday, June 2, 2025

Now that curiosity has spent some sols to collect close-up measurements of rocks at the outer edge of the fait geological unit, the team has decided it’s time to collect drilling samples. Geochemical measurements of APX and Chemcam have shown changes since we spanned from previous sulfate units, but we cannot find out mineralogy based solely on these data. As we often see on Mars, the same chemical elements can crystallize into many different mineral combinations. This is even more so in sedimentary rocks like those we are driving, where different grains may form in our rocks at different times and places. This also means that when we get mineral data, these minerals tell us a lot about the history of these new rocks.

In curiosity, mineral analysis is the work of the Chemin instrument, which uses X-ray diffraction to identify minerals. Chemin shines through the powder sample with a narrow X-ray beam to generate a diffraction pattern, meaning it requires drilling the sample. So today's team is busy finding locations to drill. Unfortunately, the drill bits of the rover extend from today's parking space only have rocks that are too broken or too much debris sitting on them are thought to produce a good sample of drilling, so we have to move or "bump" at least and then do a drill bit again before drilling pre-tightening tests, which is the next step of drilling.

Meanwhile, we are doing more measurements to understand the range of compositions that can be found in this rock layer. Dust removal (DRT) + APXS + LIBS + MAHLI are all planned for the target "Holcomb Valley" while the second drt/apxs/mahli measurements are planned for the "Santa Ysabel Valley" and in the other direction, the second Libs are used for the "Stoff Saddle". Plan to cover a long-distance Chemcam remote imaging mosaic in the distance. MastCam's imaging day was relatively light, and apart from recording two LIBS targets, only a few small mosaics covered nearby slot functions and provided background for the RMI she wanted to structure. The modern Martian environment also records several movies to look for dust activity, measurements of atmospheric opacity, and a pair of suprahorizon observations to find clouds, and the usual passive observations of Dan and REMS to monitor neutron environments, temperatures and humidity.

I'm going to be doing the ROVER program under the theme of "Geology and Mineralology Science" on Wednesday and look forward to what we've found - hopefully there are some drillable boxing units on the bed!