Sols 4488-4490: Progress Through the Ankle-Breaking Terrain
by Lucy Lim, Planetary Scientist at NASA’s Goddard Space Flight Center
Pasadena CA (JPL) Mar 26, 2025
Earth planning date: Friday, March 21, 2025: It’s the start of spring here in the Northern Hemisphere on Earth, but in Gale Crater on Mars our rover is still heading into the depths of Martian winter. We’re just a few weeks away from Mars’ aphelion – the time when it’s farthest from the Sun. The Mars-Sun distance varies more significantly than the Earth-Sun distance because of the greater eccentricity of Mars’ orbit, and its effect on the Martian weather is correspondingly more important.
As my colleague mentioned in the previous blog post, the layered sulfate bedrock in this region is broken up into large blocks that often make the driving tough going. The drive in the sol 4486 plan went very well, however, moving Curiosity nearly 35 meters (about 115 feet) southward and upward. Our new workspace is in one of the “light-toned” stripes that can be seen in the orbital imagery and is correspondingly full of light-toned laminated blocks typical of what we’ve seen before in this geologic unit.
For the second plan in a row we were also able to use the rover arm, due to the rover having parked in a stable position – not always a given in this terrain! This enabled us to plan a pair of compositional measurements by the APXS on a bedrock target (“Solstice Canyon”) to assess both the bedrock composition after dust removal and the effect of the ubiquitous dust on the instrument at other locations where the rock cannot be brushed. Our other compositional measurement tool, the LIBS, was also recruited for a co-targeted measurement on Solstice Canyon.
The second LIBS measurement and a MAHLI observation went to the one distinctive, potentially diagenetic, feature visible among all of the light-toned workspace blocks, a small grayish patch that looks like a vein or a coating in the images available at planning (“Black Oak”). The planned observations will give us both the composition and morphology of it in much greater detail.
A long-distance RMI imaging mosaic was planned to investigate some ridges on an as-yet-unnamed butte off to the west. The ridges may be evidence of the same type of diagenetic activity that produced the boxwork structures that are the next major science target for Curiosity. A passive spectral raster was also planned for a potential boxwork region. As we won’t be able to rove to every potential boxwork on Aeolis Mons, longer-distance views such as these can give us a sense of how widespread the boxwork-forming activity may have been.
Mastcam imaging included some follow-up on a hummocky sedimentary feature (“Pino Alto”) and documentation of textures in the nearby local bedrock (“Piedra Blanca”) as well as documentation imagery for the two LIBS targets.
Finally, the modern Martian atmosphere was investigated with measurements by APXS and the ChemCam passive imager to track abundances of argon and oxygen, respectively, as they vary with the Martian seasons.
Sols 4486-4487: Ankle-Breaking Kind of Terrain!
by Catherine O’Connell-Cooper, Planetary Geologist at University of New Brunswick
Earth planning date: Wednesday, March 19, 2025: This terrain is a tricky drive, with rocks angled chaotically all around. One of our geologists remarked that they wouldn’t like to even walk over this without solid boots coming way up over the ankles – this is definitely the kind of terrain to result in twisted and broken ankles! So it wasn’t too unexpected that the drive we had planned on Monday cut short after 18 meters (about 59 feet). Fortunately, we ended up both at a workspace with abundant bedrock and in an orientation that allowed us to pass SRAP (our “Slip Risk Assessment Process”).
The rover planners were quickly able to find a spot to brush, so we have a coordinated target on “Palm Grove,” one of the laminated rocks in the lower half of the accompanying image. APXS and MAHLI will look at this target on the first sol of the plan, and then ChemCam LIBS and Mastcam will look at it on the second sol. Although the bulk of the bedrock is relatively nodule free, ChemCam will look at the nodular target “Refugio” to compare to the more dominant, nodule-poor bedrock.
On Monday, our workspace included some very interesting layers in the bedrock that might represent preserved sand ripples, but sadly, as Conor reported on Monday, we didn’t pass SRAP, which precluded any contact science. However, today we ended up near rocks that had similar layer geometry, and will acquire a MAHLI “Dog’s Eye” or mosaic image of these rocks at “Duna Vista” and two Mastcam 5×3 mosaics (“Bayside Trail” and “Oso Flaco”) on other examples.
Mastcam is taking several other images here. A 14×3 mosaic will capture the “nearfield” or area close to the rover, and a set of four further images focus on four distinct trough features, to help us better understand ongoing modification of the surface. Further afield, the “Quartz Hill” and “Pino Alto” mosaics look at areas of fragmented bedrock which may be similar to the “Humber Park” outcrop we analyzed this past weekend. Even further from the rover, ChemCam will acquire RMI (Remote Micro Imager) images of the “Boxworks” and an almost circular depression (“Torote Bowl”) whose origin is not clear.
The environmental theme group (ENV) planned a Mastcam tau (to look at dust in the atmosphere) and a Navcam dust-devil survey (to look for dust devils!) for the first sol of the plan. On the second sol, we fill out the movies with Navcam movies looking toward the south of the crater (suprahorizon, cloud shadow, and zenith movies) and a Mastcam sky survey.
In between the movies on the second sol, our drive is planned to take us another 34 meters (about 112 feet)… but we will have to see how far our intrepid rover will make it on this tricky terrain. Slow and steady will win this race!
Related Links
MSL Updates
Mars News and Information at MarsDaily.com
Lunar Dreams and more
